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                                                                    EXHIBIT 10.3

                                 CERTICOM CORP.



                                       and



                      COMPUTERSHARE TRUST COMPANY OF CANADA



                                   as Trustee






                        ________________________________



                                 TRUST INDENTURE


                        ________________________________




                             7.25% Convertible Notes



                           Dated as of August 30, 2001

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     THIS CONVERTIBLE NOTE INDENTURE is made as of August 30, 2001.

BETWEEN:

          CERTICOM CORP., a corporation continued under the laws
          of the Yukon Territory and having an office in the City
          of Toronto, in the Province of Ontario (hereinafter
          referred to as the "Corporation")

                                      -and-

          COMPUTERSHARE TRUST COMPANY OF CANADA, a trust company
          organized under the laws of Canada and having an office
          in the City of Toronto, in the Province of Ontario
          (hereinafter referred to as the "Trustee")

     WHEREAS the Corporation is proposing to issue Convertible Notes in the
manner herein set forth;

     AND WHEREAS each Convertible Note shall entitle the holder thereof to
acquire an aggregate principal amount of Convertible Debentures equal to the
aggregate principal amount represented by such Convertible Note, at no
additional cost and upon the terms and conditions herein set forth;

     AND WHEREAS the Corporation represents to the Trustee that all necessary
resolutions of the Corporation have been duly enacted, passed or confirmed and
all other proceedings taken and conditions complied with to authorize the
execution and delivery of this Indenture and the execution and issue of the
Convertible Notes and to make the same legal and valid and binding on the
Corporation in accordance with the laws applicable to the Corporation;

     AND WHEREAS the Trustee has agreed to act as trustee for the Convertible
Noteholders on the terms and conditions herein set forth;

     AND WHEREAS all acts and deeds necessary have been done and performed to
make the Convertible Notes, when certified by the Trustee and issued as provided
for in this Indenture, legal and valid and binding upon the Corporation with the
benefits and subject to the terms of this Indenture;

     AND WHEREAS the foregoing recitals are made as representations and
statements of fact by the Corporation and not by the Trustee.

     NOW THEREFORE, THIS INDENTURE WITNESSETH that for good and valuable
consideration mutually given and received, the receipt and sufficiency of which
is hereby acknowledged, the parties hereto agree as follows:

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                                       -3-

                           ARTICLE 1 - INTERPRETATION

1.1  Definitions

     In this Indenture, including the recitals and schedules hereto, and in all
indentures supplemental hereto, the following words and terms shall have the
indicated meanings:

     (a)  "Affiliate" has the meaning ascribed to such term in the Business
          Corporations Act (Ontario);

     (b)  "Applicable Legislation" means the provisions of the Business
          Corporations Act (Ontario), as from time to time amended, and any
          other statute of Canada or a province thereof, and the regulations and
          rules under any such named or other statute, relating to trust
          indentures or to the rights, duties and obligations of trustees and of
          corporations under trust indentures, to the extent that such
          provisions are at the time in force and applicable to this Indenture;

     (c)  "Applicable Securities Law" means, collectively, the applicable
          securities laws of each of the Qualifying Jurisdictions and the
          respective regulations and rules made thereunder together with all
          applicable published policy statements, blanket orders and rulings of
          the Securities Commissions and all discretionary orders or rulings, if
          any, of the Securities Commissions made in connection with the
          transactions contemplated hereunder;

     (d)  "Business Day" means a day other than a Saturday, Sunday or statutory
          holiday in Toronto, Ontario;

     (e)  "Change of Control" means the occurrence of (i) a Person, including
          the Person's Affiliates and Associates, becoming the beneficial owner
          of directly or indirectly, or, exercising control or direction over,
          Common Shares carrying in excess of 50.1% of the total voting rights
          attached to the Common Shares; or (ii) the Corporation consolidating
          or amalgamating with, or merging with or into, another Person or
          selling, assigning, conveying, transferring, leasing or otherwise
          disposing of all or substantially all of its assets to any Person, or
          any Person consolidating or amalgamating with, or merging with or
          into, the Corporation, in any such event pursuant to a transaction in
          which any of the outstanding Common Shares are converted into or
          exchanged for cash, securities or other property, other than any such
          transaction in which the outstanding Common Shares are converted into
          or exchanged for, or the assets of the Corporation are exchanged for,
          voting securities or securities exchangeable at the option of the
          holder into voting securities of the surviving or transferee Person
          constituting a majority of such voting securities (giving effect to
          such issuance and the exercise of any rights to exchange such
          securities into voting securities);

     (f)  "Common Shares" means common shares in the capital of the Corporation;

     (g)  "Contingent Obligation" shall mean, as to any Person, any obligation,
          whether secured or unsecured, of such Person guaranteeing or
          indemnifying, or in effect

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                                       -4-


          guaranteeing or indemnifying, for any indebtedness, leases, dividends,
          letters of credit or other monetary obligations (the "primary
          obligations") of any other Person (the "primary obligor") in any
          manner, whether directly or indirectly, including any obligation of
          such Person as an account party in respect of a letter of credit or
          letter of guarantee issued to assure payment by the primary obligor of
          any such primary obligation and any obligation of such Person, whether
          or not contingent, (a) to purchase any such primary obligation or any
          property constituting direct or indirect security therefor, (b) to
          advance or supply funds for the purchase or payment of any such
          primary obligation or to maintain working capital or equity capital of
          the primary obligor or otherwise to maintain the net worth or solvency
          of the primary obligor, (c) to purchase property, securities or
          services primarily for the purpose of assuring the obligee under any
          such primary obligation of the ability of the primary obligor to make
          payment of such primary obligation, or (d) otherwise to assure or hold
          harmless the obligee under such primary obligation against loss in
          respect of such primary obligation; provided, however, that the term
          Contingent Obligation shall not include endorsements of instruments
          for deposit or collection in the ordinary course of business;

     (h)  "Convertible Debentures" means the debentures of the Corporation
          issuable under the Trust Indenture to holders of the Convertible
          Notes;

     (i)  "Convertible Note Agency" means the principal office of the Trustee in
          the City of Toronto or such other place as may be designated in
          accordance with subsection 3.1(c);

     (j)  "Convertible Note Certificate" means a certificate issued pursuant to
          this Indenture, in substantially the form set forth in Schedule "A",
          issued on or after the Effective Date to evidence Convertible Notes;

     (k)  "Convertible Noteholders" or "holders" without reference to
          Convertible Notes or Common Shares, means the Persons who, on and
          after the Effective Date, are registered owners of Convertible Notes;

     (l)  "Convertible Noteholders' Request" means an instrument signed in one
          or more counterparts by Convertible Noteholders representing in the
          aggregate not less than 25% of the aggregate principal amount of all
          Convertible Notes then unexercised and outstanding, requesting the
          Trustee to take or refrain from taking some action or proceeding
          specified therein;

     (m)  "Convertible Notes" means the convertible notes issued and certified
          hereunder and for the time being outstanding and entitling the holder
          to acquire Convertible Debentures in accordance with the terms and
          conditions hereof;

     (n)  "Counsel" means a barrister or solicitor or a firm of barristers and
          solicitors retained by the Trustee or retained by the Corporation and
          acceptable to the Trustee;

     (o)  "Debt" shall mean, at any time:

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                                       -5-


          (a)  all items which would then be classified as a liability on a
               consolidated balance sheet of the Corporation or in the notes
               thereto; and

          (b)  to the extent not otherwise included as Debt pursuant to the
               provisions of paragraph (a) of this definition, without
               duplication, any item which is

                    (i) an obligation of the Corporation or any of its
                    Subsidiaries in respect of borrowed money or for the
                    deferred purchase price of property or services or an
                    obligation of the Corporation which is evidenced by a note,
                    bond, debenture or other similar instrument,

                    (ii) a transfer with recourse or with an obligation to
                    repurchase, to the extent of the liability of the
                    Corporation or any of its Subsidiaries with respect thereto,

                    (iii) an obligation secured by any Lien on any property of
                    the Corporation or any of its Subsidiaries to the extent
                    attributable to its respective interest in such property,
                    even though it has not assumed or become liable for the
                    payment thereof,

                    (iv) an obligation of the Corporation or any of its
                    Subsidiaries arising in connection with an acceptance
                    facility or letter of credit or letter of guarantee issued
                    by or for the account of the Corporation or any of its
                    Subsidiaries, or

                    (v) a Contingent Obligation of the Corporation or any of its
                    Subsidiaries to the extent that the primary obligation so
                    guaranteed is not otherwise classified as a liability on the
                    consolidated balance sheet of the Corporation,

                    provided, however, that there shall not be included for the
                    purpose of this definition any item which is on account of
                    (w) issued share capital or surplus, (x) reserves for
                    deferred income taxes or general contingencies, (y) minority
                    interests in Subsidiaries, or (z) trade debt;

     (p)  "director" means a director of the Corporation for the time being and,
          unless otherwise specified herein, reference to action "by the
          directors" means action by the directors of the Corporation as a board
          or, whenever duly empowered, action by any committee of such board;

     (q)  "Effective Date" means August 30, 2001;

     (r)  "Escrow Agent" means Computershare Trust Company of Canada;

     (s)  "Escrow Agreement" means the escrow and custodial agreement dated as
          of August 30, 2001 among the Corporation, the Underwriter and the
          Escrow Agent;

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                                       -6-


     (t)  "Escrow Direction" means a direction substantially in the form
          attached hereto as Schedule "B";

     (u)  "Event of Default" means any event specified in Section 6.1, continued
          for a period of time, if any, therein designated;

     (v)  "Exercise Date" means, with respect to any Convertible Note, the date
          on which the Convertible Note is exercised in accordance with Section
          3.1 or Section 3.7, as applicable;

     (w)  "Exercise Form" means the exercise form attached to or applicable to a
          Convertible Note;

     (x)  "Expiry Date" means the earlier of:

          (i)    the date which is five Business Days following the date on
                 which the Receipt is issued; and

          (ii)   August 30, 2002;

     (y)  "Extraordinary Resolution" has the meaning Set forth in Section 7.11;

     (z)  "Final Prospectus" means the final short form prospectus of the
          Corporation qualifying the distribution, in the Qualifying
          Jurisdictions, of the Convertible Debentures to the holders of
          Convertible Notes upon exercise of the Convertible Notes;

     (aa) "Lien" means any lien, encumbrance, mortgage, pledge, charge, security
          interest or other encumbrance;

     (bb) "NASDAQ" means the Nasdaq National Market;

     (cc) "Permitted Secured Debt" means, with respect to the Corporation or any
          of its Subsidiaries:

          (i)    indebtedness (other than trade debt) created, incurred, assumed
          or guaranteed, for moneys borrowed or raised by whatever means
          (including, without limitation, by means of commercial paper, bankers'
          acceptances, debt instruments, bank debt and financial leases, and any
          liability evidenced by bonds, debentures, notes or similar
          instruments);

          (ii)   indebtedness created, incurred, assumed or guaranteed after the
          date of this Indenture to finance the cost of the acquisition by the
          Corporation or any of its Subsidiaries of any assets or services;

          (iii)  any guarantee of any indebtedness of a type described in clause
          (i) or (ii); and

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                                       -7-


          (iv)   renewals, extensions or refunds of any indebtedness or
          guarantee referred to in clauses (i), (ii) or (iii);

          provided that, in each case, such indebtedness or guarantee is secured
          by a Lien and such Lien has been created or granted for bona fide
          purposes of the Corporation or any of its Subsidiaries and not for the
          purpose of avoiding the Corporation's obligations under section
          5.2(q);

     (dd) "Person" means an individual, body corporate, partnership, trust,
          trustee, executor, administrator, legal representative or any
          unincorporated organization;

     (ee) "Preliminary Prospectus" means the preliminary short form prospectus
          of the Corporation qualifying the distribution, in the Qualifying
          Jurisdictions, of the Convertible Debentures to holders of Convertible
          Notes upon the exercise of Convertible Notes;

     (ff) "Qualifying Jurisdictions" means, collectively, the provinces of
          Ontario and Quebec;

     (gg) "Receipt" means collectively the receipts required to be issued by
          each of the Securities Commissions for the Final Prospectus;

     (hh) "Receipt Deadline" means 4:00 p.m. (Toronto time) on September 29,
          2001 or such later date as agreed to in writing by the Corporation and
          the Underwriter;

     (ii) "Securities Commissions" means the securities commission or regulatory
          authority in each of the Qualifying Jurisdictions;

     (jj) "Shareholder" means a holder of record of one or more Common Shares;

     (kk) "Subscription Funds" means the aggregate amount of the funds paid or
          consideration provided by purchasers of the Convertible Notes for such
          Convertible Notes;

     (ll) "Subsidiary" has the meaning attributed thereto in the Business
          Corporations Act (Ontario);

     (mm) "Successor Corporation" has the meaning ascribed thereto in Section
          8.2;

     (nn) "this Indenture", "herein", "hereby", "hereof" and similar expressions
          mean and refer to this Indenture and any indenture, deed or instrument
          supplemental hereto; and the expressions "Article", "Section",
          "subsection" and "paragraph" followed by a number, letter or both mean
          and refer to the specified article, section, subsection or paragraph
          of this Indenture;

     (oo) "Time of Expiry" means 5:00 p.m. (Toronto time) on the Expiry Date;

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                                       -8-


     (pp) "trade debt" means all unsecured debt of the Corporation incurred in
          connection with the purchase of goods or services in the ordinary
          course of business;

     (qq) "Trust Indenture" means the convertible debenture trust indenture
          dated as of August 30, 2001 between the Corporation and the Trustee
          providing for the issuance of $13,500,000 aggregate principal amount
          of Convertible Debentures;

     (rr) "Trustee" means Computershare Trust Company of Canada or its
          successors from time to time in the trust hereby created;

     (ss) "TSE" means The Toronto Stock Exchange;

     (tt) "Underwriter" means Yorkton Securities Inc.; and

     (uu) "written request of the Corporation" and "certificate of the
          Corporation" mean, respectively, a written order, request, consent and
          certificate signed in the name of the Corporation by its President or
          a Vice-President; and may consist of one or more instruments so
          executed.

1.2  Gender and Number

     Unless herein otherwise expressly provided or unless the context otherwise
requires, words importing the singular include the plural and vice versa and
words importing gender include all genders.

1.3  Interpretation not Affected by-Headings, etc.

     The division of this Indenture into Articles and Sections; the provision of
a table of contents and the insertion of headings are for convenience of
reference only and shall not affect the construction or interpretation of this
Indenture or any provision hereof.

1.4  Day not a Business Day

     In the event that any day on which any action is required to be taken under
this Indenture is not a Business Day, then such action shall be required to be
taken at or before the requisite time on the next succeeding day that is a
Business Day.

1.5  Time of the Essence

     Time shall be of the essence of this Indenture.

1.6  Currency

     Except as otherwise specified herein, all dollar amounts herein are
expressed in lawful money of Canada.

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                                       -9-


1.7   Meaning of "Outstanding"

      Every Convertible Note represented by a Convertible Note Certificate
countersigned and delivered by the Trustee hereunder shall be deemed to be
outstanding until it shall be cancelled or exercised pursuant to Article 3,
provided that where a new Convertible Note Certificate has been issued pursuant
to Section 2.11 hereof to replace one which has been mutilated, lost, destroyed
or stolen, the Convertible Notes represented by only one of such Convertible
Note Certificates shall be counted for the purpose of determining the aggregate
number of Convertible Notes outstanding.

1.8   Severability

      In the event that any provision hereof shall be determined to be invalid,
illegal or unenforceable in any respect, the validity, legality and
enforceability of the remainder of such provision and any other provision hereof
shall not be affected or impaired thereby.

1.9   English Language Only

      The parties to this Indenture hereby agree and request that this
Indenture, and any documents related hereto, including without limitation the
Convertible Note Certificates, be drafted only in the English language.

1.10  Schedules

      The following schedules are appended to this Indenture and are
incorporated as fully as though contained in the body of this Indenture.

      Schedule "A" - Form of Convertible Note Certificate
      Schedule "B" - Escrow Direction
      Schedule "C" - Redemption Election Notice

1.11  Date of Issue of Receipt

      The Receipt shall conclusively be deemed to be issued on the date
appearing on such Receipt as the Receipt's date.

1.12  Beneficiaries

      This Indenture is entered into by the Trustee for the benefit of all such
Persons who subscribe for and purchase Convertible Notes and each of them shall,
upon such subscription and purchase, be entered in the register as Convertible
Noteholders. The Trustee hereby declares that it holds all rights, interest and
benefits to be derived therefrom for and on behalf of all such Persons in
accordance with the terms and restrictions contained herein.

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                                      -10-


                     ARTICLE 2 - ISSUE OF CONVERTIBLE NOTES

2.1   Issue of Convertible Notes

      The aggregate principal amount of Convertible Notes authorized for issue
hereunder is limited to $13,500,000. The Corporation shall not have the right to
prepay the Convertible Notes. Notwithstanding anything to the contrary contained
in this Indenture, this Section 2.1 shall not be amended so as to increase the
aggregate principal amount of Convertible Notes that may be created and
authorized for issue hereunder without the approval of the Convertible
Noteholders by Extraordinary Resolution.

2.2   Subscription Funds

      Upon issuance of the Convertible Notes all Subscription Funds shall be
paid to the Escrow Agent in accordance with the terms of the Escrow Agreement.
Upon the earlier of (i) receipt by the Escrow Agent of an Escrow Direction, and
(ii) the Time of Expiry, the Subscription Funds, together with interest thereon,
shall be paid by the Escrow Agent to the Trustee or the Corporation, as
applicable in accordance with the provisions of Section 4.1.

2.3   Exercise of Convertible Notes

      Each Convertible Note shall entitle the holder thereof, upon exercise, to
acquire an aggregate principal amount of Convertible Debentures equal to the
aggregate principal amount of such Convertible Note, at any time until the Time
of Expiry at no additional cost to the holder.

2.4   Interest

      (a)  Each Convertible Note shall bear interest on the principal amount
           thereof from the Effective Date or the date of issue, whichever is
           later, at the rate of 7.25% per annum, after as well as before
           default, with interest on overdue interest at the same rate. Interest
           shall be based on a 365 or 366 day year, as the case may be, and
           shall be calculated semi-annually not in advance from the Effective
           Date or the date of issue of a Convertible Note, whichever is later,
           or from the last interest payment date to which interest has been
           paid or made available for payment on the Convertible Notes,
           whichever is later, and shall be paid in like money semi-annually on
           February 28 and August 30, commencing on February 28, 2002 (unless a
           Convertible Note shall have been previously exercised as duly
           provided for).

      (b)  In the event of exercise of a Convertible Note all accrued and unpaid
           interest on a Convertible Note shall be paid on then first date for
           the payment of interest following the exercise of such Convertible
           Note provided for under the terms of the Convertible Debenture into
           which such Convertible Note is exercised to the Person to whom
           interest on such Convertible Debenture is payable on such date, and
           such Person shall be entitled to the interest accrued hereunder on
           the same basis as if such interest had accrued on such Convertible
           Debenture and was payable on such interest payment date.

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                                      -11-


2.5   Payment

      (a)  As the interest on the Convertible Notes becomes due (except interest
           payable at maturity which may be paid upon presentation and surrender
           of such Convertible Notes for payment), the Corporation, either
           directly or indirectly through the Trustee, shall forward or cause to
           be forwarded by prepaid ordinary mail at least three (3) Business
           Days prior to the interest payment date, to the holder for the time
           being, or, in the case of joint holders, to one of such joint holders
           (failing written instructions to the contrary from all of such joint
           holders), at his address appearing on the register, a cheque for such
           interest (less any tax required to be deducted), payable to or to the
           order of such holder or holders and negotiable at par. The forwarding
           of such cheque shall satisfy and discharge the liability for the
           interest upon the Convertible Notes to the extent of the sums
           represented thereby (plus the amount of any tax deducted as
           aforesaid) unless such cheque is not paid on presentation; provided
           that in the event of the non-receipt of such cheque by such
           registered holder or the loss or destruction thereof, the
           Corporation, upon being furnished with reasonable evidence of such
           non-receipt, loss or destruction and indemnity reasonably
           satisfactory to it, shall issue or cause to be issued to such
           registered holder a replacement cheque for the amount of such cheque.

      (b)  The holder for the time being of any Convertible Note shall be
           entitled to the principal moneys and interest evidenced by such
           Convertible Notes, free from all equities or rights of set-off or
           counterclaim between the Corporation and the original or any
           intermediate holder thereof and all Persons may act accordingly.

2.6   Convertible Noteholder not a Shareholder

      Nothing in this Indenture nor in the holding of a Convertible Note or
Convertible Note Certificate or otherwise, shall, in itself, confer, or be
construed as conferring upon a Convertible Noteholder any right or interest
whatsoever as a Shareholder or as any other shareholder of the Corporation,
including, but not limited to, the right to vote at, to receive notice of, or to
attend meetings of shareholders or any other proceedings of the Corporation, or
the right to receive dividends and other distributions.

2.7   Convertible Notes to Rank Pari Passu

      All Convertible Notes and Convertible Debentures shall rank pari passu,
whatever may be the actual date of issue thereof.

2.8   Form and Denomination of Convertible Notes

      The Convertible Note Certificates (including all replacements issued in
accordance with this Indenture) shall be substantially in the form set out in
Schedule "A" hereto, shall be dated on or after the Effective Date, shall bear
such distinguishing letters and numbers as the Corporation may, with the
approval of the Trustee, prescribe, shall be issuable only in fully registered
form and only in integral multiples of $1,000.

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                                      -12-


2.9   Signing of Convertible Note Certificates

      The Convertible Note Certificates shall be signed by any one (1) director
or officer of the Corporation. The signatures of any such director or officer
may be mechanically reproduced by way of photocopy or facsimile and Convertible
Note Certificates bearing such photocopy or facsimile signatures shall be
binding upon the Corporation as if they had been manually signed by such
director or officer. Notwithstanding that any Person whose manual or facsimile
signature appears on any Convertible Note Certificate as a director or officer
may no longer hold office at the date of such Convertible Note Certificate or at
the date of certification or delivery thereof, any Convertible Note Certificate
signed as aforesaid shall, subject to Section 2.10, be valid and binding upon
the Corporation and the holder thereof shall be entitled to the benefits of this
Indenture.

2.10  Certification by the Trustee

      (a)  The Trustee shall certify Convertible Note Certificates upon the
           written direction of the Corporation. No Convertible Note Certificate
           shall be issued or, if issued, shall be valid for any purpose or
           entitle the holder to the benefit of this Indenture until it has been
           certified by manual signature by or on behalf of the Trustee
           substantially in the form of the certificate set out in Schedule "A"
           and such certification by the Trustee upon any Convertible Note
           Certificate shall be conclusive evidence as against the Corporation
           that the Convertible Note Certificate so certified has been duly
           issued hereunder and that the holder is entitled to the benefits of
           this Indenture.

      (b)  The certification of the Trustee on a Convertible Note Certificate
           issued hereunder shall not be construed as a representation or
           warranty by the Trustee as to the validity of this Indenture or the
           Convertible Note Certificate (except the due certification thereof)
           and the Trustee shall in no respect be liable or answerable for the
           use made of the Convertible Note Certificate or any of them or of the
           consideration therefor except as otherwise specified herein.

2.11  Issue in Substitution for Convertible Note Certificates Lost, etc.

      (a)  If any Convertible Note Certificate becomes mutilated or is lost,
           destroyed or stolen, the Corporation, subject to applicable law,
           shall issue and thereupon the Trustee shall certify and deliver, a
           new Convertible Note Certificate of like tenor as the one mutilated,
           lost, destroyed or stolen in exchange for and in place of and upon
           cancellation of such mutilated Convertible Note Certificate, or in
           lieu of and in substitution for such lost, destroyed or stolen
           Convertible Note Certificate, and the substituted Convertible Note
           Certificate shall be in a form approved by the Trustee and the
           Convertible Notes evidenced thereby shall be entitled to the benefits
           hereof and shall rank equally, in accordance with their terms, with
           all other Convertible Notes issued or to be issued hereunder.

      (b)  The applicant for the issue of a new Convertible Note Certificate
           pursuant to this Section 2.11 shall bear the cost of the issue
           thereof and in case of loss, destruction

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                                      -13-


           or theft shall, as a condition precedent to the issue thereof,
           furnish to the Corporation and to the Trustee such evidence of
           ownership and of the loss, destruction or theft of the Convertible
           Note Certificate so lost, destroyed or stolen as shall be
           satisfactory to the Corporation and to the Trustee, in their sole
           discretion, and such applicant may also be required to furnish an
           indemnity or security in amount and form satisfactory to the
           Corporation and the Trustee, in their sole discretion, and shall pay
           the reasonable charges of the Corporation and the Trustee in
           connection therewith.

2.12  Exchange of Convertible Note Certificates

      (a)  Any one or more Convertible Note Certificates representing any amount
           of Convertible Notes may, upon compliance with the reasonable
           requirements of the Trustee, be exchanged for one or more other
           Convertible Note Certificates in authorized denominations
           representing the same aggregate principal amount of Convertible Notes
           as represented by the Convertible Note Certificate or Convertible
           Note Certificates so exchanged.

      (b)  Convertible Note Certificates may be exchanged only at the
           Convertible Note Agency or at any other place that is designated by
           the Corporation, with the approval of the Trustee. Any Convertible
           Note Certificate tendered for exchange shall be cancelled and
           surrendered to the Trustee.

2.13  Registration and Transfer

      The Corporation shall, at all times while any Convertible Notes are
outstanding, cause the Trustee to maintain a register in which will be entered
the names, latest known addresses of the Convertible Noteholders and if
available, facsimile numbers of the holders and particulars of the Convertible
Notes held by them, and a register of transfers in which shall be entered the
particulars of all transfers of Convertible Notes, such registers to be kept by
and at the Convertible Note Agency.

      The Convertible Notes may only be transferred on the register kept at the
principal office of the Trustee in the City of Toronto by the holder or its
legal representatives or its attorney duly appointed by an instrument in writing
in form and execution satisfactory to the Trustee only upon surrendering to the
Trustee the Convertible Note Certificates representing the Convertible Notes to
be transferred and upon compliance with:

      (a)  the conditions herein;

      (b)  such reasonable requirements as the Trustee may prescribe (including
           evidence of compliance with item (c) of this Section 2.13 in such
           form as is satisfactory to the Trustee acting reasonably);

      (c)  all applicable securities legislation and requirements of regulatory
           authorities; and

      (d)  payment of the applicable transfer fee as per section 2.14;

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                                      -14-


and such transfer shall be duly noted in such register by the Trustee. Upon
compliance with such requirements, the Trustee shall issue to the transferee a
Convertible Note Certificate representing the Convertible Notes transferred.

2.14  Charges for Exchange or Transfer

      Except as otherwise herein provided, the Trustee may charge to a holder
requesting an exchange of a Convertible Note Certificate a reasonable sum for
each new Convertible Note Certificate issued in exchange for an existing
Convertible Note Certificate and payment of such charges and reimbursement of
the Trustee or the Corporation for any and all transfer, stamp or similar taxes
or other governmental charges required to be paid shall be made by the holder
requesting such transfer or exchange as a condition precedent to such transfer
or exchange.

2.15  Cancellation of Surrendered Convertible Notes

      All Convertible Note Certificates surrendered or purchased pursuant to
Sections 2.11, 2.12, 2.13, 3.1, 3.7, 4.1 or 5.1 shall be returned to the Trustee
for cancellation and, after the expiry of any period of retention prescribed by
law, destroyed by the Trustee. Upon request by the Corporation, the Trustee
shall furnish to the Corporation a destruction certificate identifying the
Convertible Note Certificates so destroyed, the number of Convertible Notes
evidenced thereby, the number of Convertible Debentures, if any, issued pursuant
to the exercise of such Convertible Notes and the details of any Convertible
Note Certificates issued in substitution or exchange for such Convertible Note
Certificates destroyed.

2.16  Persons Entitled to Payment

      (a)  The Corporation and Trustee will deem and treat the Person in whose
           name any Convertible Note is registered as the absolute owner thereof
           for all purposes of this Indenture and payment of or on account of
           principal or interest on such Convertible Note shall be made only to
           or to the order in writing of such holder, and neither the
           Corporation nor the Trustee shall be affected by any notice to the
           contrary, except where the Corporation or the Trustee is required to
           take notice by statutes or by order of a court of competent
           jurisdiction, and such payment shall be a good and sufficient
           discharge to the Corporation and the Trustee for all amounts so paid.

      (b)  The holder for the time being of any Convertible Note shall be
           entitled to the principal and interest evidenced by such Convertible
           Note, free from all equities or rights of set-off or counterclaim,
           between the Corporation and the original or any intermediate holder
           thereof and all Persons may act accordingly, and a transferee of a
           Convertible Note shall, after the appropriate form of transfer is
           lodged with the Trustee and upon compliance with all other conditions
           in that behalf required by this Indenture or by any conditions
           contained in such Convertible Note, be entitled to the principal and
           interest evidenced by such Convertible Note free from all equities or
           rights of set-off or counterclaim between the Corporation and his or
           her transferor or any previous holder thereof,

<PAGE>

                                       -15-


           save in respect of equities of which the Corporation is required to
           take notice by statute or by order of a court of competent
           jurisdiction.

      (c)  In the case of the death of one or more joint holders, principal or
           interest on any Convertible Note registered in their names may be
           paid to the survivor of such holders whose receipt therefor shall
           constitute a valid discharge to the Corporation and the Trustee.

2.17  U. S. Legend

      (a)  The Convertible Notes have not been and will not be registered under
           the U.S. Securities Act and may not be sold or otherwise transferred
           except pursuant to sales or other transfers that satisfy the
           requirements of Rule 904 of Regulation S under the U.S. Securities
           Act. Each Convertible Note certificate originally issued in the
           United States or to, or for the account of, a U.S. Person, and each
           Convertible Note Certificate issued in exchange therefor or in
           substitution thereof (each a "Restricted Convertible Note") shall
           bear the following legend:

      "THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
      UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE "U.S. SECURITIES
      ACT") OR UNDER ANY STATE SECURITIES LAWS. THE HOLDER HEREOF, BY PURCHASING
      SUCH SECURITIES, AGREES FOR THE BENEFIT OF CERTICOM CORP. THAT SUCH
      SECURITIES MAY BE OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO
      CERTICOM CORP., (B) OUTSIDE THE UNITED STATES IN ACCORDANCE WITH RULE 904
      OF REGULATION S UNDER THE U.S. SECURITIES ACT, (C) PURSUANT TO THE
      EXEMPTION FROM REGISTRATION UNDER THE U.S. SECURITIES ACT PROVIDED BY RULE
      144 THEREUNDER, IF AVAILABLE, OR (D) IN COMPLIANCE WITH CERTAIN OTHER
      PROCEDURES SATISFACTORY TO CERTICOM CORP. DELIVERY OF THIS CERTIFICATE MAY
      NOT CONSTITUTE "GOOD DELIVERY" IN SETTLEMENT OF TRANSACTIONS ON STOCK
      EXCHANGES IN CANADA. A NEW CERTIFICATE, BEARING NO LEGEND, DELIVERY OF
      WHICH WILL CONSTITUTE "GOOD DELIVERY" MAY BE OBTAINED FROM COMPUTERSHARE
      TRUST COMPANY OF CANADA. UPON DELIVERY OF THIS CERTIFICATE AND A DULY
      EXECUTED DECLARATION, IN A FORM SATISFACTORY TO COMPUTERSHARE TRUST
      COMPANY OF CANADA AND THE CORPORATION TO THE EFFECT THAT THE SALE OF THE
      SECURITIES REPRESENTED HEREBY IS BEING MADE IN COMPLIANCE WITH RULE 904 OF
      REGULATION S UNDER THE U.S. SECURITIES ACT;"

provided, that if the Securities are being sold in compliance with the
requirements of Rule 904 of Regulation S under the U.S. Securities Act and in
compliance with Canadian local laws and regulations, the legend may be removed
by providing a declaration to Computershare Trust Company of Canada, as
registrar and transfer agent for the Securities, to the following effect (or as
the Corporation may prescribe from time to time):

<PAGE>

                                      -16-


     The undersigned (A) acknowledges that the sale of the Securities to which
     this declaration relates is being made in reliance on Rule 904 of
     Regulation S under the United States Securities Act of 1933, as amended
     (the "U.S. Securities Act"), and (B) certifies that (1) it is not an
     "affiliate" (as defined in Rule 405 under the U.S. Securities Act) of
     Certicom Corp., (2) the offer of such Securities was not made to a person
     in the United States and either (a) at the time the buy order was
     originated, the buyer was outside the United States, or the seller and any
     person acting on its behalf reasonably believed that the buyer was outside
     the United States or (b) the transaction was executed on or through the
     facilities of The Toronto Stock Exchange and neither the seller nor any
     person acting on its behalf knows that the transaction has been prearranged
     with a buyer in the United States and (3) neither the seller nor any person
     acting on its behalf engaged in any directed selling efforts in connection
     with the offer and sale of such Securities. Terms used herein have the
     meanings given to them by Regulation S;

provided, further, that, if any such Securities are being sold pursuant to Rule
144 of the U.S. Securities Act, the legend may be removed by delivery to
Computershare Trust Company of Canada of an opinion of counsel, of recognized
standing reasonably satisfactory to the Corporation, to the effect that such
legend is no longer required under applicable requirements of the U.S.
Securities Act or state securities laws.

     (b)  Notwithstanding any other provisions of this Indenture, in processing
          and registering transfers of Convertible Notes, no duty or
          responsibility whatsoever shall rest upon the Trustee to determine the
          compliance by any transferor or transferee with the terms of the
          legend contained in subsection 2.17(a), or with the relevant
          securities laws or regulations, including, without limitation,
          Regulation S and the Trustee shall be entitled to assume that all
          transfers are legal and proper.

                   ARTICLE 3 - EXERCISE OF CONVERTIBLE NOTES

3.1  Exercise of Convertible Notes

     (a)  Subject to Section 3.4, the holder of any Convertible Note may
          exercise the right conferred on such holder to acquire Convertible
          Debentures by surrendering, prior to the Time of Expiry, at the
          Convertible Note Agency the Convertible Notes Certificate representing
          such Convertible Note with a duly completed and executed Exercise
          Form.

          A Convertible Note Certificate with the duly completed and executed
          Exercise Form referred to in this subsection 3.1(a) shall be deemed to
          be surrendered only upon personal delivery thereof or, if sent by mail
          or other means of transmission, upon actual receipt thereof at, in
          each case, the Convertible Note Agency.

     (b)  Any Exercise Form referred to in subsection 3.1(a) shall be signed by
          the Convertible Noteholder and shall specify:

          (i)    the aggregate principal amount of Convertible Debentures which
                 the holder wishes to acquire (being not more than that amount
                 which the

<PAGE>

                                      -17-


                 holder is entitled to acquire pursuant to the Convertible Note
                 Certificate(s) surrendered);

          (ii)   the Person or Persons in whose name or names such Convertible
                 Debentures are to be issued;

          (iii)  the address or addresses of such Persons;

          (iv)   the aggregate principal amount of Convertible Debentures to be
                 issued to each such Person if more than one Person is so
                 specified; and

          (v)    social insurance number, if applicable.

          If any of the Convertible Debentures subscribed for are to be issued
          to a Person or Persons other than the Convertible Noteholder, the
          Convertible Noteholder shall pay to the Corporation, or the Trustee on
          behalf of the Corporation, all applicable transfer or similar taxes
          and the Corporation shall not be required to issue or deliver
          certificates evidencing Convertible Debentures unless or until such
          Convertible Noteholder shall have paid to the Corporation, or the
          Trustee on behalf of the Corporation, the amount of such tax or shall
          have established to the satisfaction of the Corporation that such tax
          has been paid or that no tax is due.

     (c)  In connection with the exchange or transfer of Convertible Note
          Certificates and the exercise of Convertible Notes, the Corporation
          hereby appoints the principal office of the Trustee in the City of
          Toronto as the agency at which Convertible Note Certificates may be
          surrendered for exchange or transfer or at which Convertible Notes may
          be exercised. The Corporation may from time to time designate
          alternate or additional places as the Convertible Note Agency and
          shall give notice to the Trustee of any change of the Convertible Note
          Agency.

3.2  Effect of Exercise of Convertible Notes

     (a)  Upon the exercise of Convertible Notes pursuant to Section 3.1 or
          Section 3.7, and subject to Section 3.3 the aggregate principal amount
          of Convertible Debentures into which Convertible Notes are exercised
          shall be deemed to have been issued and the Person or Persons to whom
          such Convertible Debentures are to be issued shall be deemed to have
          become the holder or holders of record of such aggregate principal
          amount of Convertible Debentures on the Exercise Date or, if the
          transfer registers of the Corporation shall be closed on such date, on
          the date on which such transfer registers are reopened.

     (b)  Subject to Section 3.7, within five Business Days after the Exercise
          Date with respect to a Convertible Note, the Corporation shall cause
          to be mailed or delivered to the Person or Persons in whose name or
          names the Convertible Debentures are to be issued, in such aggregate
          principal amount or number as specified in the applicable Exercise
          Form, at the address specified in such Exercise Form or, if so
          specified in such Exercise Form, delivered at the Convertible Note
          Agency where the applicable Convertible Note Certificate was

<PAGE>

                                      -18-


          surrendered, a certificate or certificates for the appropriate
          aggregate principal amount of Convertible Debentures into which such
          Convertible Note is exercised.

3.3  Partial Exercise of Convertible Notes; Fractions

     (a)  The holder of any Convertible Notes may acquire an aggregate principal
          amount of Convertible Debentures less than the aggregate principal
          amount which the holder is entitled to acquire pursuant to any
          surrendered Convertible Note Certificate for exercise. In the event of
          any exercise of an aggregate principal amount of Convertible Notes
          less than the aggregate principal amount into which a Convertible Note
          is exercisable the holder of the Convertible Notes upon such exercise
          shall, in addition, be entitled to receive, without charge therefor, a
          new Convertible Note Certificate in respect of the balance of the
          principal amount of Convertible Notes represented by the unexercised
          portion of the surrendered Convertible Note Certificate.

     (b)  Notwithstanding anything herein contained, the Corporation shall not
          be required, upon the exercise of any Convertible Notes, to issue
          Convertible Debentures in denominations of less than $1,000 and
          multiples thereof or to distribute certificates which evidence
          Convertible Debentures other than in $1,000 denominations and
          multiples thereof.

3.4  Exercise by Certain Persons Restricted

     The Convertible Notes may not be exercised by any Person resident in a
jurisdiction which is not a Qualifying Jurisdiction unless the distribution of
Convertible Debentures to such Person can be lawfully made without the
Corporation being required to qualify such distribution in any manner under
applicable law.

3.5  Reliance By Trustee

     The Trustee shall have no obligation to ensure or verify compliance with
any Applicable Legislation or regulatory requirements on the issue, exercise or
transfer of any Convertible Notes or any underlying Convertible Debentures or
Common Shares or other securities issuable upon the exercise of any Convertible
Notes. The Trustee shall be entitled to process all proffered transfers and
exercises of Convertible Notes upon the presumption that such transfers or
exercises are permissible pursuant to all Applicable Legislation and regulatory
requirements and the terms of the Indenture and the related Convertible Note
Certificates, provided that transfers and exercises of Convertible Notes, or the
underlying Convertible Debentures or Common Shares or other securities issuable
upon the exercise of any Convertible Notes, bearing the U.S. Legend may only be
processed by the Trustee upon written instruction of the Corporation to the
Trustee, which instruction may be based, in the Corporation's discretion, upon
certificates, opinions and other documentation of the holders of such
Convertible Notes or underlying Convertible Debentures or Common Shares. The
Trustee may assume for the purposes of this Indenture that the address on the
register of Convertible Noteholders of any Convertible Notes is the Convertible
Noteholder's actual address and is also determinative of the Convertible
Noteholder's residency and that the address of any transferee to whom any
Convertible Notes or

<PAGE>

                                      -19-


underlying Convertible Debentures or Common Shares or other securities issuable
upon the exercise of any Convertible Notes are to be registered, as shown on the
transfer document, is the transferee's actual address and is also determinative
of the transferee's residency.

3.6  Expiration of Convertible Notes

     (a)  Subject to Section 3.7, immediately after the Time of Expiry, all
          rights to acquire Convertible Debentures under any Convertible Note in
          respect of which such right shall not have been exercised shall cease
          and terminate, and, subject to Section 3.7, such Convertible Note
          shall be void and of no further force or effect.

     (b)  If for any reason, the exercise of Convertible Notes in accordance
          with the terms hereof is prohibited by law or does not take place as
          contemplated herein (including by order of any securities regulatory
          authority or court of competent jurisdiction) such Convertible Notes
          shall, notwithstanding anything to the contrary herein contained,
          remain valid and outstanding, and shall continue to bear interest at
          the rate herein provided and shall be due and payable in full on the
          sixth Business Day following the Expiry Date provided the Convertible
          Notes are then outstanding.

3.7  Accounting and Recording

     (a)  Any securities or other instruments, from time to time received by the
          Trustee shall be received in trust for, and shall be segregated and
          kept apart by the Trustee in trust for, the Corporation.

     (b)  The Trustee shall record the particulars of Convertible Notes
          exercised, which particulars shall include the names and addresses of
          the Persons who become holders of Convertible Debentures on the
          exercise thereof and the Exercise Date, if any, in respect thereof.
          The Trustee shall provide such particulars in writing to the
          Corporation within five Business Days of any request by the
          Corporation therefor.

3.8  Automatic Exercise

     Any Convertible Notes which are not exercised prior to the Expiry Time
shall be deemed to be exercised by the holders thereof immediately prior to the
Expiry Time to convert Convertible Notes into Convertible Debentures without any
further action on behalf of such holder. Following such exercise, such
Convertible Notes shall be cancelled and of no further force and effect other
than evidence of entitlement to receive the Convertible Debentures resulting
from the conversion of Convertible Notes upon the automatic exercise of any
Convertible Notes, which shall be issued upon the surrender of the related
Convertible Note Certificate accompanied with the duly completed and executed
Exercise Form, either by personal delivery thereof to the Trustee at the
Convertible Note Agency or at any other place or places that may be designated
by the Corporation with the approval of the Trustee, or, if sent by mail upon
actual receipt thereof by the Trustee at the Convertible Note Agency. Within two
Business Days of the Expiry Date, the Corporation shall notify holders of the
Convertible Notes that have

<PAGE>

                                      -20-


not exercised such Convertible Notes prior to the Time of Expiry that such
Convertible Notes have been automatically exercised and converted.

3.9  Securities Restrictions

     Notwithstanding anything herein contained, Convertible Debentures will only
be issued upon exercise of any Convertible Note in compliance with the
securities laws of any applicable jurisdiction, and without limiting the
generality of the foregoing, in the event that the Convertible Notes are
exercised pursuant to Section 3.1 prior to the issuance of a Receipt, the
certificates representing the Convertible Debentures thereby issued, or any
Common Shares into which the Convertible Debentures are converted, will bear
such legend as may, in the opinion of counsel to the Corporation, be necessary
in order to avoid a violation of any securities laws of any province in Canada
or to comply with the requirements of any stock exchange on which the Common
Shares are listed, provided that if, at any time, in the opinion of counsel to
the Corporation, such legends are no longer necessary in order to avoid a
violation of any such laws, or the holder of any such legended certificate, at
the holders expense, provides the Corporation with evidence satisfactory in form
and substance to the Corporation (which may include an opinion of counsel
satisfactory to the Corporation, acting reasonably) to the effect that such
holder is entitled to sell or otherwise transfer such Convertible Debentures or
Common Shares in a transaction in which such legends are not required, such
legended certificate may thereafter be surrendered to the Corporation in
exchange for a certificate which does not bear such legend.

ARTICLE 4 - REDEMPTION

4.1  Redemption

     (a)  If the Corporation has not obtained a Receipt on or before the Receipt
          Deadline, then:

          (i)    each Convertible Noteholder will be entitled to elect (the
                 "Redemption Election") to cause the Corporation to redeem all,
                 but not less than all, the Convertible Notes held by such
                 Convertible Noteholder at a price (the "Redemption Price") per
                 Convertible Note equal to the principal amount thereof,
                 together with accrued and unpaid interest on the principal
                 amount of the Convertible Note so redeemed to but not including
                 the date fixed for redemption (the "Redemption Date"), which
                 date shall not be less than 15 Business Days after the date of
                 receipt or deemed receipt of a Redemption Election Notice (as
                 defined herein) by the Convertible Noteholders;

          (ii)   the Redemption Election may be exercised by delivery to the
                 Corporation of a notice of exercise (a "Redemption Election
                 Notice") substantially in the form attached hereto as Schedule
                 "C" prior to 5:00 p.m. (Toronto time) on the third Business Day
                 immediately preceding the Redemption Date by the Convertible
                 Noteholders;

          (iii)  notwithstanding Section 4.1(a)(i), in the event that
                 Convertible Noteholders representing in the aggregate more than
                 50% of the aggregate

<PAGE>

                                      -21-

               principal amount of the Convertible Notes outstanding on
               September 28, 2001 elect to cause the Corporation to redeem the
               Convertible Notes held by such Convertible Noteholders, all
               outstanding Convertible Notes shall be redeemed (a "Mandatory
               Redemption") by the Corporation on the Redemption Date at a price
               per Convertible Note equal to the Redemption Price;

        (iv)   the Corporation shall, on or before October 2, 2001, deliver or
               cause to be delivered to each Convertible Noteholder and the
               Trustee a notice stating (A) that a Receipt was not obtained by
               the Corporation prior to the Receipt Deadline, (b) that each
               Convertible Noteholder has the rights set forth in, and shall be
               subject to the provisions of, Sections 4.1(a)(i), (ii) and (iii),
               as applicable, and (C) the Redemption Date, and including a
               Redemption Election Notice in the form attached hereto as
               Schedule "C".

        (v)    if the Corporation is required to redeem any Convertible Notes
               pursuant to this Section 4.1, the Corporation shall deliver to
               the Escrow Agent, not later than 5:00 p.m. (Toronto time) on the
               second Business Day immediately preceding the Redemption Date, an
               Escrow Direction;

        (vi)   the Corporation shall redeem, on the Redemption Date, (A) in the
               event of a Mandatory Redemption, all of the outstanding
               Convertible Notes, or (B) such aggregate principal amount of
               Convertible Notes as shall be specified in duly completed
               Redemption Election Notices delivered to the Corporation pursuant
               to Section 4.1(a)(ii), as applicable, at a price per Convertible
               Note equal to the Redemption Price; and

        (vii)  except in the case of a Mandatory Redemption, the Escrow Agent
               shall pay or cause to be paid to the Corporation that portion of
               the Subscription Funds, including interest thereon, not required
               to pay the Redemption Price of any Convertible Notes redeemed on
               the Redemption pursuant to a Redemption Election.

(b)     Upon compliance by the Corporation with the provisions of Section
        4.1(a)(v), all of the outstanding Convertible Notes so called for
        redemption shall thereupon become due and payable at the Redemption
        Price on the Redemption Date and from and after the Redemption Date
        such Convertible Notes shall not be considered as outstanding hereunder
        and interest on such Convertible Notes shall cease.

(c)     From the sums deposited with the Trustee by the Escrow Agent pursuant
        to the Escrow Direction, the Trustee shall deliver, pay or cause to be
        delivered and paid to the holders of Convertible Notes so redeemed,
        upon surrender of such Convertible Notes, the moneys to which the
        Convertible Noteholders are respectively entitled on redemption.

<PAGE>
                                       -22-

        (d)    If the Trustee determines that the sums deposited with the
               Trustee by the Escrow Agent will not be sufficient to allow the
               Trustee to pay the Redemption Price with respect to Convertible
               Notes to be redeemed in accordance with this Section 4.1, the
               Trustee shall give notice of such determination to the
               Corporation and the Corporation shall, within three Business Days
               of the date upon which such notice is received, pay to the
               Trustee such amount as shall be sufficient, together with the
               sums deposited with the Trustee by the Escrow Agent, to allow the
               Trustee to pay the Redemption Price with respect to Convertible
               Notes to be redeemed in accordance with this Section 4.1.

        ARTICLE 5 - RIGHTS OF THE CORPORATION AND COVENANTS. REPRESENTATIONS AND
                    WARRANTIES

5.1     Optional Purchases by the Corporation

        The Corporation may from time to time purchase with the consent of the
Convertible Noteholder, by private contract or otherwise any of the Convertible
Notes. Any such purchases shall be offered to all Convertible Noteholders on a
pro rata basis. Any such purchase shall be made at the lowest price or prices at
which, in the opinion of the directors, such Convertible Notes are then
obtainable from such Convertible Noteholder, plus reasonable costs of purchase,
and may be made in such manner, from such Persons and on such other terms as the
Corporation may determine. Any Convertible Note Certificates representing the
Convertible Notes purchased pursuant to this Section 5. 1 shall forthwith be
delivered to and cancelled by the Trustee. No Convertible Notes shall be issued
in replacement thereof.

5.2     General Covenants of the Corporation

        The Corporation covenants and agrees with the Trustee that so long as
any Convertible Notes remain outstanding:

        (a)    it shall duly and punctually pay or cause to be paid to every
               Convertible Noteholder the principal of and interest on each of
               the Convertible Notes (including, in the case of default,
               interest on the amount in default) at the places, at the
               respective times and in the manner provided herein and in the
               Convertible Notes;

        (b)    except as herein otherwise expressly provided, the Corporation
               will at all times maintain its corporate existence and will keep
               proper books of account in accordance with generally accepted
               accounting practices. Upon written notice from the Trustee
               stating that it has reasonable grounds to believe that an Event
               of Default has occurred or may occur, the Corporation will
               furnish or cause to be furnished to the Trustee or its duly
               authorized agent or attorney such information relating to its
               business as the Trustee may reasonably require and the books of
               account will be made available for inspection by the Trustee or
               such agent or attorney;

<PAGE>
                                       -23-

        (c)    the Corporation will furnish to the Trustee a copy of all
               financial statements, whether annual or interim, of the
               Corporation and the report, if any, of the Corporation's auditors
               thereon and of all annual and other periodic reports of the
               Corporation furnished to its shareholders at the same time as
               they are furnished to such shareholders. No obligation shall rest
               with the Trustee to analyze such statements or evaluate the
               performance of the Corporation in any manner whatsoever;

        (d)    the Corporation will reserve and there will remain created and
               unissued a sufficient aggregate principal amount of Convertible
               Debentures to satisfy its obligations upon the exercise of
               Convertible Notes and it will reserve and authorize the issuance
               of a sufficient number of Common Shares for the purpose of
               enabling it to satisfy its obligations to issue Common Shares in
               accordance with the terms of the Convertible Debentures issued
               upon the exercise of the Convertible Notes;

        (e)    the Corporation will cause the Convertible Debentures and
               certificates representing the Convertible Debentures from time to
               time issued pursuant to the exercise of the Convertible Notes to
               be duly issued and delivered in accordance with the Convertible
               Notes and the terms hereof;

        (f)    the Corporation will cause the Common Shares and the certificates
               representing the Common Shares from time to time issued in
               accordance with the terms of the Convertible Debentures to be
               duly issued and delivered in accordance with the Convertible
               Debentures and the terms of the Trust Indenture;

        (g)    all Common Shares issued in accordance with the terms of the
               Convertible Debentures shall be fully paid and non-assessable;

        (h)    the Corporation will use its commercially reasonable efforts to
               obtain a Receipt, as soon as reasonably possible, from the
               Securities Commissions for the Final Prospectus so that the
               resale of such Convertible Debentures and Common Shares issuable
               in accordance with the terms of the Convertible Debentures will
               not generally be subject to the prospectus requirements or any
               "hold period" under Applicable Securities Law in the Qualifying
               Jurisdictions;

        (i)    generally, the Corporation will duly and punctually perform and
               carry out all of the acts or things to be done by it as provided
               in this Indenture;

        (j)    the Corporation shall not, directly or indirectly, declare or pay
               any dividends on account of any shares or any class of its shares
               now or hereafter outstanding or redeem, retire, defease, purchase
               or otherwise acquire any shares of any class of capital stock (or
               set aside or otherwise deposit or invest any sums for any of the
               foregoing purposes) or apply or set apart any sum, or make any
               other distribution (by reduction of capital or otherwise) in
               respect of any such shares or agree to do any of the foregoing;

<PAGE>
                                       -24-

        (k)    in order to prevent any accumulation after maturity of unpaid
               interest on, or of unpaid principal amount of, any Convertible
               Note, the Corporation will not directly or indirectly extend or
               assent to the extension of time for payment of any interest upon
               any Convertible Note or of any principal amount payable in
               respect of any Convertible Note and that it will not directly or
               indirectly be or become a party to or approve any such
               arrangement by purchasing or funding any interest on the
               Convertible Notes or any principal amount thereof or in any other
               manner and that the Corporation will deliver to the Trustee all
               Convertible Notes when paid as evidence of such payment;

        (l)    if the time for the payment of any interest or principal amount
               shall be so extended, whether or not such extension is by or with
               the consent of the Corporation, notwithstanding anything herein
               or in the Convertible Notes contained, such interest or principal
               amount shall not be entitled, in case of default hereunder, to
               the benefit of this Indenture except subject to the prior payment
               in full of the principal amount of all the Convertible Notes then
               outstanding and of all matured interest on such Convertible Notes
               the payment of which has not been so extended;

        (m)    on or before August 30, 2002 and on or before August 30 in each
               subsequent year and at any other reasonable time if requested by
               the Trustee, the Corporation will furnish to the Trustee a
               Certificate of the Corporation stating that the Corporation has
               complied with all covenants, conditions and other requirements
               contained in this Indenture, non-compliance with which would
               constitute an Event of Default hereunder or, if such is not the
               case, specifying the covenant, condition or other requirement
               which has not been complied with and giving particulars of such
               non-compliance and the action, if any, the Corporation proposes
               to take with respect thereto;

        (n)    the Corporation will take all commercially reasonable steps and
               actions and do all such acts and things as may be required to:
               (i) as long as it meets the minimum listing requirements of such
               institutions, maintain the listing and posting for trading, on
               the TSE, of the Common Shares or, in the event of a Change of
               Control, on the TSE, NASDAQ or the New York Stock Exchange the
               securities for which the Common Shares were exchanged or
               converted in connection with the Change of Control, and (ii)
               maintain its status as a reporting issuer not in default of the
               requirements of applicable securities legislation of the
               provinces of Canada or have outstanding securities registered
               under the Securities Exchange Act of 1934, as amended, or, in the
               event of a Change of Control, maintain the status of the Person,
               or such Person's Affiliate, whose securities were exchanged or
               converted for Common Shares in connection with such Change of
               Control as a reporting issuer not in default of the requirements
               of applicable securities legislation in the Province of Ontario
               or have securities outstanding registered under the Securities
               Exchange Act of 1934, as amended;

<PAGE>
                                       -25-

        (o)    the Corporation shall, within three Business Days of a written
               request by the Trustee, furnish to the Trustee, or to such other
               Person as the Trustee may direct, a true copy of this Indenture;

        (p)    the Corporation shall not change its name or amalgamate with
               another corporation under a different name without giving at
               least ten days' prior notice to the Trustee of the new name and
               the date upon which such change of name or amalgamation is to
               take effect and, within five Business Days of the change of name
               or amalgamation, the Corporation shall provide the Trustee with:

               (i)    a notarial or certified copy of the articles of amendment
                      or articles of amalgamation effecting the change of name;
                      and

               (ii)   an opinion from legal counsel satisfactory to the Trustee
                      as to the correct name of the Corporation and confirming
                      that all appropriate registrations, filings or recordings
                      have been made to ensure the continued validity and
                      enforceability of this Indenture and the Convertible
                      Notes;

        (q)    the Corporation represents and warrants to the Trustee that there
               is no (i) Permitted Secured Debt or (ii) Debt ranking senior to,
               or pari passu, with the Debentures outstanding or in effect on
               the date of this Indenture, except such Permitted Secured Debt as
               has been incurred to finance the cost of acquisition by the
               Corporation or any of its Subsidiaries of any assets or services
               in the ordinary course of their respective businesses. The
               Corporation will not, and will not permit any of its Subsidiaries
               to, create, incur, assume, suffer, permit to exist or guarantee,
               directly or indirectly, any Debt that ranks senior to, or pari
               passu, with the Debentures other than Permitted Secured Debt.
               Nothing in this section 5.2(q) will prevent or be deemed to
               prevent the Corporation or any of its Subsidiaries from creating,
               incurring, assuming, suffering, permitting to exist or
               guaranteeing trade debt;

        (r)    the Corporation shall promptly notify the Trustee in writing of
               the details of the occurrence of any Event of Default; and

        (s)    if the closing price of the Common Shares on NASDAQ is less than
               U.S. $1.00 for any period of 10 consecutive trading days, the
               Corporation will consider calling a special meeting of its
               shareholders for the purpose of approving a consolidation of the
               Common Shares on such terms as the directors of the Corporation
               may approve.

5.3     Trustee's Remuneration and Expenses

        (a)    The Corporation covenants that it will pay to the Trustee
               reasonable remuneration for its services as Trustee and will pay
               all costs, charges and expenses (including reasonable fees and
               disbursements of its Counsel and all other advisors not regularly
               in its employ) properly incurred by the Trustee in connection
               with the trusts hereof, on demand by the Trustee and also (in
               addition to any right of indemnity given to the Trustee by law)
               will at all times keep indemnified the

<PAGE>
                                       -26-

               Trustee against all liabilities, losses, damages, actions,
               proceedings, costs, claims, expenses and demands in respect of
               any matter or thing done or omitted by the Trustee (other than
               through the gross negligence of or misconduct by the Trustee) in
               any way relating to this Indenture. The said remuneration shall
               continue to be payable until the trusts hereof be finally wound
               up and whether or not the trusts of this Indenture shall be in
               the course of administration by or under the direction of the
               court.

         (b)   Any amount due under this Section 5.3 and unpaid 30 days after
               demand for such payment shall bear interest from the expiration
               of such 30 day period at a rate per annum equal to the rate
               generally charged by the Corporate Trust Department of the
               Trustee from time to time on overdue accounts. After default all
               amounts so payable and the interest thereon shall be payable out
               of any funds coming into possession of the Trustee in priority to
               any payment of the principal amount of, or any interest on, the
               Convertible Notes.

5.4      Securities Qualification Requirements

         (a)   Following the Effective Date, the Corporation shall, as soon as
               reasonably possible, file with the Securities Commissions the
               Preliminary Prospectus and all such other documents as may be
               required under Applicable Securities Law with the Securities
               Commissions and use its commercially reasonable efforts to obtain
               all required receipts therefor from the Securities Commissions.

         (b)   The Corporation shall, after satisfaction of any comments with
               respect to the Preliminary Prospectus by the Securities
               Commissions, file the Final Prospectus and all such other
               documents as may be required under Applicable Securities Law with
               the Securities Commissions, and undertakes to use its
               commercially reasonable efforts to obtain a Receipt therefor from
               the Securities Commissions as soon as reasonably possible but in
               any event by the Receipt Deadline and to take all other
               commercially reasonable steps as may be necessary to qualify the
               distribution in the Qualifying Jurisdictions of the Convertible
               Debentures and Common Shares issuable in accordance with the
               terms of the Convertible Debentures, provided that the
               Corporation shall not be obligated to file the Final Prospectus
               on or after August 30, 2002.

         (c)   The Corporation shall send written notice to each holder of
               Convertible Notes and the Trustee advising of the issuance of a
               Receipt by the Securities Commissions together with a copy of the
               Final Prospectus. Such notice shall be hand delivered or mailed
               to each holder of the Convertible Notes at the address of each
               such holder appearing in the register of the Convertible Notes
               maintained pursuant to this Indenture within five Business Days
               after the date on which a Receipt was issued by the Securities
               Commissions.

<PAGE>
                                       -27-

5.5     Performance of Covenants by Trustee

        If the Corporation shall fail to perform any of its covenants contained
in this Indenture, the Trustee may notify the Convertible Noteholders of such
failure on the part of the Corporation or may itself perform any of the
covenants capable of being performed by it but, subject to Section 9.2, shall be
under no obligation to perform said covenants or to notify the Convertible
Noteholders of such performance by it. All sums reasonably expended or advanced
by the Trustee in so doing shall be repayable as provided in Section 5.3. No
such performance, expenditure or advance by the Trustee shall relieve the
Corporation of any default hereunder or of its continuing obligations under the
covenants herein contained.

                             ARTICLE 6 - ENFORCEMENT

6.1     Events of Default

        If any of the Events of Default listed below in this Section 6.1 shall
occur and be continuing:

         (a)   the Corporation shall default in payment of the principal on any
               Convertible Note when the same becomes due under any provision
               hereof or of the Convertible Notes; or

         (b)   the Corporation shall default in payment of any interest due on
               any Convertible Notes when the same becomes due under any
               provision hereof or of the Convertible Notes and any such default
               continues for a period of five days; or

         (c)   the Corporation shall default in the performance, or breach, of
               any covenant or agreement of the Corporation in this Indenture or
               the Convertible Notes, continued for a period of 30 days after
               there has been given notice, by registered or certified mail, to
               the Corporation by the Trustee or by Holders of not less than 25%
               of the principal amount of Convertible Notes then outstanding
               specifying such default or breach and requiring it to be
               remedied, unless the Trustee (having regard to the subject matter
               of the default) shall have agreed to a longer period and, in such
               event, for the period agreed to by the Trustee; or

         (d)   the institution by the Corporation of proceedings to be
               adjudicated a bankrupt or insolvent, or the consent by it to the
               institution of bankruptcy or insolvency proceedings against it,
               or the filing by it of a petition or answer or consent seeking
               reorganization or relief under any applicable federal, provincial
               or state law relating to bankruptcy, insolvency, reorganization
               or relief of debtors, or the consent by it to the filing of any
               such petition or to the appointment under any such law of a
               receiver, liquidator, assignee, trustee, sequestrator (or other
               similar official) of the Corporation or of substantially all of
               its property, or the making by it of a general assignment for the
               benefit of creditors, or the admission by it in writing of its
               inability to pay its debts generally as they become due; or

<PAGE>
                                       -28-

         (e)   the entry of a decree or order by a court having jurisdiction in
               the premises adjudging the Corporation a bankrupt or insolvent,
               or approving as properly filed a petition seeking reorganization,
               arrangement or adjustment of or in respect of the Corporation
               under any applicable law relating to bankruptcy, insolvency,
               reorganization or relief of debtors, or appointing under any such
               law a receiver, liquidator, assignee, trustee, sequestrator (or
               other similar official) of the Corporation or of substantially
               all of its property, or ordering pursuant to any such law the
               winding-up or liquidation of its affairs, and the continuance of
               any such decree, petition, appointment or order unstayed and in
               effect for a period of 90 consecutive days; or

         (f)   if an encumbrancer takes possession of, or appoints a receiver in
               respect of, all or substantially all of the property of the
               Corporation, or if any process or execution is levied or enforced
               upon or gains all or substantially all of the property of the
               Corporation and remains unsatisfied for such period as would
               permit any such property to be sold thereunder, unless the
               Corporation actively and diligently contests in good faith such
               process, but in that event the Corporation shall, if the Trustee
               so requires, give security which, in the discretion of the
               Trustee, is sufficient to pay in full the amount thereby claimed
               in case the claim is held to be valid;

then, in each and every such event, if such event is continuing, subject to
Section 6.3 and Section 7.10(d), the Trustee may in its discretion and shall,
upon receipt of a Convertible Noteholders' Request, declare the principal of,
and interest on, all Convertible Notes then outstanding and all other moneys
outstanding hereunder to be due and payable, and the same shall forthwith become
immediately due and payable to the Trustee, anything therein or herein to the
contrary notwithstanding, and the Corporation shall forthwith pay to the Trustee
for the benefit of the Convertible Noteholders the amount of the principal of,
and interest then accrued on, all of the Convertible Notes then outstanding and
all other moneys outstanding hereunder, together with interest thereon, at the
rate of interest borne by the Convertible Notes from the date of the said
declaration until payment is received by the Trustee and such payment when made
shall be deemed to have been made on such Convertible Notes and shall be applied
as provided in Section 6.5.

6.2     Notice of Events of Default

        If an Event of Default shall occur and be continuing the Trustee shall,
as soon as reasonably possible but in any event within 15 days after it becomes
aware of the occurrence of such Event of Default, give notice of such Event of
Default, to the Convertible Noteholders in the manner provided in Article 10;
provided that, notwithstanding the foregoing, unless the Trustee shall have been
requested to do so pursuant to a Convertible Noteholders' Request, the Trustee
shall not be required to give such notice, if the Trustee, in good faith,
reasonably believes that it is in the best interests of the Convertible
Noteholders to withhold such notice and shall have so informed the Corporation
in writing.

<PAGE>
                                       -29-

6.3     Waiver of Default

        Upon the happening of any Event of Default, except default in payment
of principal, and in addition to the powers exercisable by the Convertible
Noteholders by Extraordinary Resolution, the holders of not less than 51% in
principal amount of all the Convertible Notes which shall then be outstanding
shall have power, by an instrument or instruments in writing or by affirmative
votes of such holders at a meeting duly convened and held as hereinafter
provided, to cancel any declaration made by the Trustee pursuant to Section 6.1
or to require the Trustee to waive the default, or both, and such declaration
shall thereupon be cancelled or the Trustee shall thereupon waive the default,
in either case, upon such terms and conditions as such holders shall prescribe.
So long as it has not become bound as provided in this Article 6 to declare the
principal of and interest on all the Convertible Notes then outstanding to be
due and payable, or to obtain and enforce payment of the same, the Trustee shall
have the power to waive any default arising hereunder if, in the reasonable
opinion of the Trustee, acting in good faith, the same shall have been cured, or
adequate satisfaction made therefor, upon such terms and conditions as the
Trustee may deem advisable. Provided always that no act or omission either of
the Trustee or of the Convertible Noteholders in the premises shall extend to or
be taken in any manner whatsoever to affect any subsequent default or the rights
resulting therefrom.

6.4     Right of Trustee to Enforce Payment

        (a)    Subject to the provisions of Section 6.3, if the Corporation
               shall fail to pay to the Trustee, on demand, the principal of and
               interest on all Convertible Notes then outstanding which shall
               have been declared by the Trustee to be due and payable pursuant
               to Section 6.1, together with any other amounts due hereunder,
               the Trustee may in its discretion and shall upon receipt of a
               Convertible Noteholders' Request and upon being funded and
               indemnified to its reasonable satisfaction against all costs,
               expenses and liabilities to be incurred, proceed in its name as
               Trustee hereunder to obtain or enforce payment of the said
               principal of and interest on all the Convertible Notes then
               outstanding together with any other amounts due hereunder, by any
               remedy provided by law either by legal proceedings or otherwise.

        (b)    The Trustee shall be entitled and empowered, either in its own
               name or as trustee of an express trust, or as attorney-in-fact
               for the holders of the Convertible Notes, or in any one or more
               of such capacities, to file such proof of debt, amendment of
               proof of debt, claim, petition or other document as may be
               necessary or advisable in order to have the claims of the Trustee
               and of the holders of the Convertible Notes allowed in any
               insolvency, bankruptcy, liquidation or other judicial proceedings
               relative to the Corporation or its creditors or relative to or
               affecting its property. The Trustee is hereby irrevocably
               appointed (and the successive respective holders of the
               Convertible Notes by taking and holding the same shall be
               conclusively deemed to have so appointed the Trustee) the true
               and lawful attorney-in-fact of the respective holders of the
               Convertible Notes with authority to make or file in the
               respective names of the holders of the Convertible Notes or on
               behalf of the holders of the Convertible Notes as a class,
               subject to deduction from any such claims of the amounts of any
               claims filed by any of the holders of

<PAGE>

                                       -30-

        the Convertible Notes themselves, any proof of debt, amendment of proof
        of debt, claim, petition or other document in any proceedings and to
        receive payment of any sums becoming distributable on account thereof,
        and to execute any such other papers and documents and to do and perform
        any and all such acts and things for and on behalf of such holders of
        the Convertible Notes, as may be necessary or advisable in the opinion
        of the Trustee, in order to have the respective claims of the Trustee
        and of the holders of the Convertible Notes against the Corporation or
        its property allowed in any such proceeding, and to receive payment of
        or on account of such claims; provided, however, that nothing contained
        in this Indenture shall be deemed to give to the Trustee, unless so
        authorized by Extraordinary Resolution, any right to accept or consent
        to any plan of reorganization or otherwise by action of any character in
        such proceeding to waive or change in any way any right of any
        Convertible Noteholder.

        (c)    Any such suit or proceeding instituted by the Trustee shall be
               brought in the name of the Trustee as trustee of an express
               trust, and any recovery of judgment shall be for the rateable
               benefit of the holders of the Convertible Notes subject to the
               provisions of this Indenture. In any proceeding brought by the
               Trustee (and also any proceeding in which a declaratory judgment
               of a court may be sought as to the interpretation or construction
               of any provision of this Indenture, to which the Trustee shall be
               a party) the Trustee shall be held to represent all the holders
               of the Convertible Notes, and it shall not be necessary to make
               any holders of the Convertible Notes parties to any such
               proceeding.

6.5     Application of Moneys

        (a)    Except as herein otherwise expressly provided, any moneys
               received by the Trustee from the Corporation pursuant to the
               foregoing Sections of this Article 6, or as a result of legal or
               other proceedings or from any trustee in bankruptcy or liquidator
               of the Corporation, shall be applied, together with any other
               moneys in the hands of the Trustee available for such purposes,
               as follows:

               FIRST:    to the payment and reimbursement to the Trustee of the
                         amounts contemplated by Section 5.3, including, without
                         limitation, compensation, costs, charges, expenses,
                         borrowings, advances, or other moneys furnished or
                         provided by or at the instance of the Trustee in or
                         about the execution of its trust or otherwise in
                         relation to this Indenture, with interest thereon as
                         herein provided;

               SECOND:   subject to Section 5.4 and as hereinafter in this
                         Section 6.5 provided, in payment rateably and
                         proportionately of the principal of and accrued and
                         unpaid interest and interest on amounts in default on
                         the Convertible Notes which shall then be outstanding
                         in the priority of principal first and then accrued and
                         unpaid interest and interest on amounts in default,
                         unless otherwise directed by Extraordinary Resolution
                         and, in that case, in such order of priority

<PAGE>
                                       -31-

                        as between principal and interest as may be directed by
                        such resolution; and

               THIRD:   the surplus (if any) of such moneys shall be paid to the
                        Corporation or its assigns;

provided, however, that no payment shall be made in respect of the principal of
or interest on any Convertible Note held, directly or indirectly, by or for the
benefit of the Corporation or any Subsidiary (other than any Convertible Note
pledged for value and in good faith to a Person other than the Corporation or
any Subsidiary but only to the extent of such Person's interest therein) except
subject to the prior payment in full of the principal of, and premium, if any,
and interest of all Convertible Notes which are not so held.

        (b)    Provided always that the Trustee shall not be bound to apply or
               make any partial or interim payment of any moneys coming into its
               hands pursuant to the foregoing Sections of this Article 6 if the
               amount so received by it is insufficient to make a distribution
               of at least 2% of the principal amount of the outstanding
               Convertible Notes but it may retain the money so received by it
               and deposit the same in its deposit department or in a chartered
               bank in Canada to its credit at such rate of interest as is then
               current on similar deposits or invest the same as provided in
               Section 12.10 of the Trust Indenture until the moneys or the
               investments representing the same, with the income derived
               therefrom together with any other moneys for the time being under
               its control shall be sufficient for the said purpose or until it
               shall consider it advisable to apply the same in the manner above
               set forth.

6.6     Notice of Payment by Trustee

        Not less than 21 days' notice shall be given by the Trustee to the
Convertible Noteholders of any payment to be made under this Article 6 to the
Convertible Noteholders. Such notice shall state the time when and the place
where such payment is to be made, and the amount of the payment and the
application thereof as between principal and interest. After the day so fixed,
unless payment shall have been duly demanded and have been refused, the
Convertible Noteholders will be entitled to interest only on the balance (if
any) of the principal moneys and interest due to them, respectively, on the
Convertible Notes, after deduction of the respective amounts payable in respect
thereof on the day so fixed.

6.7     Trustee May Demand Production of Convertible Notes

        The Trustee shall have the right to demand production of the
Convertible Notes in respect of which any payment of principal or interest
required by this Article 6 is made and may cause to be endorsed on the same
memorandum of the amount so paid and the date of payment, but the Trustee may,
in its discretion, dispense with such production and endorsement in any special
case, upon such indemnity being given to it and to the Corporation as the
Trustee shall deem sufficient.

<PAGE>
                                       -32-

6.8      Trustee Appointed Attorney

         The Corporation hereby irrevocably appoints the Trustee to be the
attorney of the Corporation for and in the name and on behalf of the Corporation
to execute any instruments and to do any acts and things which the Corporation
ought to sign, execute and do hereunder and generally to use the name of the
Corporation in the exercise of all or any of the powers hereby conferred on the
Trustee, with full powers of substitution and revocation.

6.9      Suits by Convertible Noteholders

         No Convertible Noteholder shall have the right to institute any action,
suit or proceeding, judicial or otherwise, with respect to this Indenture or for
the appointment of a receiver or trustee, or for any other remedy authorized or
permitted by this Indenture or by law or by equity hereunder, unless:

         (a)   such Convertible Noteholder has previously given written notice
               to the Trustee, or vice versa, of a continuing Event of Default;

         (b)   the Trustee shall have received a Convertible Noteholders'
               Request requesting the Trustee to institute proceedings in
               respect of such Event of Default in its own name as Trustee
               hereunder and the Trustee shall have been offered a reasonable
               opportunity either itself to proceed to exercise the powers
               hereinbefore granted or to institute an action, suit or
               proceeding in its name for such purpose;

         (c)   the Convertible Noteholder or Convertible Noteholders executing
               such Convertible Noteholders' Request have provided to the
               Trustee sufficient funds and/or indemnity against the costs,
               expenses and liabilities to be incurred in compliance with such
               request in accordance with subsection 9.2(b);

         (d)   the Trustee, for 60 days after its receipt of such notice,
               Convertible Noteholders' Request and provision of funds and/or
               indemnity, has failed to institute any such proceeding; and

         (e)   no direction inconsistent with such written request has been
               given to the Trustee during such 60-day period by the Convertible
               Noteholders of a majority or more in principal amount of the
               outstanding Convertible Notes.

         In such event but not otherwise any Convertible Noteholder. acting on
behalf of himself and all other Convertible Noteholders, shall be entitled to
take proceedings in any court of competent jurisdiction such as the Trustee
might have taken under Section 6.4, but in no event shall any Convertible
Noteholder or combination of Convertible Noteholders have any right to take any
other remedy or proceedings out of court; it being understood and intended that
no one or more Convertible Noteholders shall have any right in any manner
whatever by virtue of, or by availing of, any provision of this Indenture to
affect, disturb or prejudice the rights of any other Convertible Noteholders, or
to obtain or to seek to obtain priority or preference over any other Convertible
Noteholders or to enforce any right under this Indenture, except in the manner
herein provided and for the equal and rateable benefit of all the Convertible
Noteholders.

<PAGE>
                                       -33-

6.10     Immunity of Shareholders, etc.

         The Trustee and, by the acceptance of the Convertible Note Certificates
and as part of the consideration for the issue of the Convertible Notes, the
Convertible Noteholders, hereby waive and release any right, cause of action or
remedy now or hereafter existing in any jurisdiction against any incorporator or
any past, present or future shareholder, director, officer, employee or agent of
the Corporation or any Successor Corporation on any covenant, agreement,
representation or warranty by the Corporation contained in this Indenture or in
the Convertible Note Certificates.

6.11     Limitation of Liability

         The obligations hereunder are not personally binding upon, nor shall
resort hereunder be had to, the private property of any of the past, present or
future directors or shareholders of the Corporation or any Successor Corporation
or any of the past, present or future officers, employees or agents of the
Corporation or any Successor Corporation, but only the property of the
Corporation or any Successor Corporation shall be bound in respect hereof.

6.12     Remedies Cumulative

         No remedy herein conferred upon or reserved to the Trustee, or upon or
to the Convertible Noteholders, is intended to be exclusive of any other remedy,
but each and every such remedy shall be cumulative and shall be in addition to
every other remedy given hereunder or now existing or hereafter to exist by law
or by statute.

                 ARTICLE 7 - MEETINGS OF CONVERTIBLE NOTEHOLDERS

7.1      Right to Convene Meetings

         The Trustee may at any time and from time to time, and shall on receipt
of a written request of the Corporation or of a Convertible Noteholders' Request
and upon being indemnified to its reasonable satisfaction by the Corporation or
by the Convertible Noteholders signing such Convertible Noteholders' Request
against the cost which may be incurred in connection with the calling and
holding of such meeting, call and hold a meeting of the Convertible Noteholders.
In the event of the Trustee failing to so call a meeting within 15 days after
receipt of such written request of the Corporation or such Convertible
Noteholders' Request and indemnity given as aforesaid, the Corporation or such
Convertible Noteholders who signed such Convertible Noteholders' Request, as the
case may be, may call and hold such meeting. Every such meeting shall be held in
the City of Toronto or at such other place as may be approved by the Trustee and
the Corporation

7.2      Notice

         At least 21 days' prior notice of any meeting of Convertible
Noteholders shall be given to the Convertible Noteholders entitled to attend
such meeting in the manner provided for in Section 10.2 and a copy of such
notice shall be sent by mail to the Trustee (unless the meeting has been called
by the Trustee) and to the Corporation (unless the meeting has been called by
the

<PAGE>
                                       -34-

Corporation). Such notice shall state the time when and the place where the
meeting is to be held, shall state briefly the general nature of the business to
be transacted thereat and shall contain such information as is reasonably
necessary to enable the Convertible Noteholders to make a reasoned decision on
the matter, but it shall not be necessary for any such notice to set out the
terms of any resolution to be proposed or any of the provisions of this Article
7. The notice convening any such meeting may be signed by an appropriate officer
of the Trustee or by the Corporation or by the holder or holders convening the
meeting.

7.3      Chairman

         An individual (who need not be a Convertible Noteholder) designated in
writing by the Trustee shall be chairman of the meeting and if no individual is
so designated, or if the individual so designated is not present within 30
minutes from the time fixed for the holding of the meeting, the Convertible
Noteholders present in Person or by proxy shall choose some individual present
to act as chairman.

7.4      Quorum

         Subject to the provisions of Section 7.11, at any meeting of the
Convertible Noteholders a quorum shall consist of Convertible Noteholders
present in Person or by proxy and holding Convertible Notes having an aggregate
principal amount of at least 25 % of the aggregate principal amount of the then
outstanding Convertible Notes, provided that at least two Persons entitled to
vote thereat are personally present. If a quorum of the Convertible Noteholders
shall not be present within 30 minutes from the time fixed for holding any
meeting, the meeting, if summoned by Convertible Noteholders or on a Convertible
Noteholders' Request, shall be dissolved; but in any other case the meeting
shall be adjourned to the same day in the next week (unless such day is not a
Business Day, in which case it shall be adjourned to the next following Business
Day) at the same time and place and no notice of the adjournment need be given.
Any business may be brought before or dealt with at an adjourned meeting which
might have been dealt with at the original meeting in accordance with the notice
calling the same. No business shall be transacted at any meeting unless a quorum
be present at the commencement of business. At the adjourned meeting the
Convertible Noteholders present in Person or by proxy shall form a quorum and
may transact the business for which the meeting was originally convened,
notwithstanding that they do not hold Convertible Notes in an aggregate
principal amount of at least 25% of the aggregate principal amount of then
outstanding Convertible Notes.

7.5      Power to Adjourn

         The chairman of any meeting at which a quorum of the Convertible
Noteholders is present may, with the consent of the meeting, adjourn any such
meeting, and no notice of such adjournment need be given except such notice, if
any, as the meeting may prescribe.

7.6      Show of Hands

         Every question submitted to a meeting shall be decided in the first
place by a majority of the votes given on a show of hands except that votes on
an Extraordinary Resolution shall be given in the manner hereinafter provided.
At any such meeting, unless a poll is duly demanded as herein provided, a
declaration by the chairman that a resolution has been carried or carried

<PAGE>
                                       -35-

unanimously or by a particular majority or lost or not carried by a particular
majority shall be conclusive evidence of the fact.

7.7      Poll and Voting

         (a)  On every Extraordinary Resolution, and on any other question
              submitted to a meeting and after a vote by show of hands when
              demanded by the chairman or by one or more of the Convertible
              Noteholders acting in Person or by proxy and holding Convertible
              Notes in the aggregate principal amount of at least 5% of the
              aggregate principal amount of all the Convertible Notes then
              outstanding, a poll shall be taken in such manner as the chairman
              shall direct. Questions other than those required to be determined
              by Extraordinary Resolution shall be decided by a majority of the
              votes cast on the poll.

         (b)  On a show of hands, every Person who is present and entitled to
              vote, whether as a Convertible Noteholder or as proxy for one or
              more absent Convertible Noteholders, or both, shall have one vote.
              On a poll, each Convertible Noteholder present in Person or
              represented by a proxy duly appointed by instrument in writing
              shall be entitled to one vote in respect of each $1,000 principal
              amount of Convertible Note or Convertible Notes then held or
              represented by such holder or Person. A proxy need not be a
              Convertible Noteholder. The chairman of any meeting shall be
              entitled, both on a show of hands and on a poll, to vote in
              respect of the Convertible Notes, if any, held or represented by
              him or her.

7.8      Regulations

         The Trustee, or the Corporation with the approval of the Trustee, may
from time to time make and from time to time vary such regulations as it shall
think fit for:

         (a)  the setting of the record date for a meeting for the purpose of
              determining Convertible Noteholders entitled to receive notice of
              and to vote at the meeting;

         (b)  the issue of voting certificates by any bank, trust company or
              other depositary satisfactory to the Trustee stating that the
              Convertible Note Certificates specified therein have been
              deposited with it by a named Person and will remain on deposit
              until after the meeting, which voting certificate shall entitle
              the Persons named therein to be present and vote at any such
              meeting and at any adjournment thereof or to appoint a proxy or
              proxies to represent them and vote for them at any such meeting
              and at any adjournment thereof in the same manner and with the
              same effect as though the Persons so named in such voting
              certificates were the actual holders of the Convertible Note
              Certificates specified therein;

         (c)  the deposit of voting certificates and instruments appointing
              proxies at such place and time as the Trustee, the Corporation or
              the Convertible Noteholders convening the meeting, as the case may
              be, may in the notice convening the meeting direct;

<PAGE>
                                      -36-

         (d)   the deposit of voting certificates and instruments appointing
               proxies at some approved place or places other than the place at
               which the meeting is to be held and enabling particulars of such
               instruments appointing proxies to be mailed or telecopied before
               the meeting to the Corporation or to the Trustee at the place
               where the same is to be held and for the voting of proxies so
               deposited as though the instruments themselves were produced at
               the meeting;

         (e)   the form of the instrument of proxy; and

         (f)   generally for the calling of meetings of Convertible Noteholders
               and the conduct of business thereat.

Any regulations so made shall be binding and effective and the votes given in
accordance therewith shall be valid and shall be counted. Save as such
regulations may provide, the only Persons who shall be recognized at any meeting
as a Convertible Noteholder, or be entitled to vote or be present at the meeting
in respect thereof (subject to Section 7.9), shall be Convertible Noteholders or
their counsel, or proxies of Convertible Noteholders.

7.9      Corporation and Trustee May be Represented

         The Corporation and the Trustee, by their respective directors and
officers, the counsel for the Corporation and the Counsel for the Trustee may
attend any meeting of the Convertible Noteholders, but shall not be entitled to
vote thereat, whether in respect of any Convertible Notes held by them or
otherwise.

7.10     Powers Exercisable by Extraordinary Resolution

         In addition to all other powers conferred upon them by any other
provisions of this Indenture or by law, the Convertible Noteholders at a meeting
shall, subject to the provisions of Section 7.11, have the power, exercisable
from time to time by Extraordinary Resolution:

         (a)   to agree to any modification, abrogation, alteration, compromise
               or arrangement of the rights of Convertible Noteholders or the
               Trustee in its capacity as trustee hereunder or on behalf of the
               Convertible Noteholders whether such rights arise under this
               Indenture or the Convertible Note Certificates or otherwise and
               to authorize the Trustee to concur in and execute any indenture
               supplemental hereto in connection therewith;

         (b)   to amend, alter or repeal any "Extraordinary Resolution"
               previously passed or sanctioned by the Convertible Noteholders;

         (c)   to direct or to authorize the Trustee to enforce any of the
               covenants on the part of the Corporation contained in this
               Indenture or the Convertible Note Certificates or to enforce any
               of the rights of the Convertible Noteholders in any manner
               specified in such Extraordinary Resolution or to refrain from
               enforcing any such covenant or right;

<PAGE>
                                      -37-

          (d)  to waive, and to direct the Trustee to waive, any default on the
               part of the Corporation in complying with any provisions of this
               Indenture or the Convertible Note Certificates either
               unconditionally or upon any conditions specified in such
               Extraordinary Resolution;

          (e)  to restrain any Convertible Noteholder from taking or instituting
               any suit, action or proceeding against the Corporation for the
               enforcement of any of the covenants on the part of the
               Corporation in this Indenture or the Convertible Note
               Certificates or to enforce any of the rights of the Convertible
               Noteholders;

          (f)  to direct any Convertible Noteholder who, as such, has brought
               any suit, action or proceeding to stay or to discontinue or
               otherwise to deal with the same upon payment of the costs,
               charges and expenses reasonably and properly incurred by such
               Convertible Noteholder in connection therewith;

          (g)  to assent to any change in or omission from the provisions
               contained in the Convertible Note Certificates and this Indenture
               or any ancillary or supplemental instrument which may be agreed
               to by the Corporation, and to authorize the Trustee to concur in
               and execute any ancillary or supplemental indenture embodying the
               change or omission;

          (h)  to remove the Trustee and to appoint a successor Trustee in the
               manner specified in Section 9.7 hereof;

          (i)  to appoint a committee with power and authority to exercise, and
               to direct the Trustee to exercise, on behalf of the Convertible
               Noteholders, such powers of the holders as are exercisable by
               Extraordinary Resolution; and

          (j)  to assent to any compromise or arrangement with any creditor or
               creditors or any class or classes of creditors, whether secured
               or otherwise, and with holders of any shares or other securities
               of the Corporation;

7.11     Meaning of Extraordinary Resolution

          (a)  The expression "Extraordinary Resolution" when used in this
               Indenture means, subject as hereinafter provided in this Section
               7.11 and in Section 7.14, a resolution proposed at a meeting of
               Convertible Noteholders duly convened for that purpose and held
               in accordance with the provisions of this Article 7 at which
               there are present in Person or by proxy Convertible Noteholders
               holding Convertible Notes in an aggregate principal amount equal
               to at least 25% of the aggregate principal amount of all the then
               outstanding Convertible Notes and passed by the affirmative votes
               of Convertible Noteholders holding Convertible Notes in an
               aggregate principal amount equal to not less than 66 "% of the
               aggregate principal amount of all the then outstanding
               Convertible Notes represented at the meeting and voted on the
               poll upon such resolution.

          (b)  If, at the meeting at which an Extraordinary Resolution is to be
               considered, Convertible Noteholders holding Convertible Notes in
               an aggregate principal

<PAGE>

                                      -38-

               amount equal to at least 25% of the aggregate principal amount of
               all the then outstanding Convertible Notes are not present in
               Person or by proxy within 30 minutes after the time appointed for
               the meeting, then the meeting, if convened by Convertible
               Noteholders or on a Convertible Noteholders' Request, shall be
               dissolved; but in any other case it shall stand adjourned to such
               day, being not less than 15 or more than 60 days later, and to
               such place and time as may be appointed by the chairman. Not less
               than ten days prior notice shall be given of the time and place
               of such adjourned meeting in the manner provided for in Section
               10.2. Such notice shall state that at the adjourned meeting the
               Convertible Noteholders present in Person or by proxy shall form
               a quorum but it shall not be necessary to set forth the purposes
               for which the meeting was originally called or any other
               particulars. At the adjourned meeting the Convertible Noteholders
               present in Person or by proxy shall form a quorum and may
               transact the business for which the meeting was originally
               convened and a resolution proposed at such adjourned meeting and
               passed by the requisite vote as provided in subsection 7.11(a)
               shall be an Extraordinary Resolution within the meaning of this
               Indenture notwithstanding that Convertible Noteholders holding
               Convertible Notes in an aggregate principal amount equal to at
               least 25% of the aggregate principal amount of all the then
               outstanding Convertible Notes are not present in Person or by
               proxy at such adjourned meeting.

          (c)  Votes on an Extraordinary Resolution shall always be given on a
               poll and no demand for a poll on an Extraordinary Resolution
               shall be necessary.

7.12      Powers Cumulative

          Any one or more of the powers or any combination of the powers in this
Indenture stated to be exercisable by the Convertible Noteholders by
Extraordinary Resolution or otherwise may be exercised from time to time and the
exercise of any one or more of such powers or any combination of powers from
time to time shall not be deemed to exhaust the right of the Convertible
Noteholders to exercise such power or powers or combination of powers then or
thereafter from time to time.

7.13      Minutes

          Minutes of all resolutions and proceedings at every meeting of
Convertible Noteholders shall be made and duly entered in books to be provided
from time to time for that purpose by the Trustee at the expense of the
Corporation, and any such minutes as aforesaid, if signed by the chairman or the
secretary of the meeting at which such resolutions were passed or proceedings
had shall be prima facie evidence of the matters therein stated and, until the
contrary is proved, every such meeting in respect of the proceedings of which
minutes shall have been made shall be deemed to have been duly convened and
held, and all resolutions passed thereat or proceedings taken shall be deemed to
have been duly passed and taken.

<PAGE>
                                      -39-

7.14     Instruments in Writing

         All actions which may be taken and all powers that may be exercised by
the Convertible Noteholders at a meeting held as provided in this Article 7 may
also be taken and exercised by Convertible Noteholders holding Convertible Notes
in an aggregate principal amount equal to at least 66 2/3% of the aggregate
principal amount of all the then outstanding Convertible Notes by an instrument
in writing signed in one or more counterparts by such Convertible Noteholders in
Person or by attorney duly appointed in writing, and the expression
"Extraordinary Resolution" when used in this Indenture shall include an
instrument so signed.

7.15     Binding Effect of Resolutions

         Every resolution and every Extraordinary Resolution passed in
accordance with the provisions of this Article 7 at a meeting of Convertible
Noteholders shall be binding upon all the Convertible Noteholders, whether
present at or absent from such meeting, and every instrument in writing signed
by Convertible Noteholders in accordance with Section 7.14 shall be binding upon
all the Convertible Noteholders, whether signatories thereto or not, and each
and every Convertible Noteholder and the Trustee (subject to the provisions for
indemnity herein contained) shall be bound to give effect accordingly to every
such resolution and instrument in writing.

7.16     Holdings by Corporation Disregarded

         In determining whether Convertible Noteholders holding Convertible Note
Certificates evidencing the required principal amount of Convertible Notes then
outstanding are present at a meeting of Convertible Noteholders for the purpose
of determining a quorum or have concurred in any consent, waiver, Extraordinary
Resolution, Convertible Noteholders' Request or other action under this
Indenture, Convertible Notes owned legally or beneficially by the Corporation or
any Subsidiary of the Corporation shall be disregarded in accordance with the
provisions of Section 10.8.

                      ARTICLE 8 - SUPPLEMENTAL INDENTURES

8.1      Provision for Supplemental Indentures for Certain Purposes

         From time to time the Corporation (when authorized by action of the
directors) and the Trustee may, subject to the provisions hereof, and they
shall, when so directed in accordance with the provisions hereof, execute and
deliver by their proper officers, indentures or instruments supplemental hereto,
which thereafter shall form part hereof, for any one or more or all of the
following purposes:

         (a)   adding to the provisions hereof such additional covenants and
               enforcement provisions as, in the opinion of Counsel, are
               necessary or advisable in the premises, provided that the same
               are not in the opinion of the Trustee prejudicial to the
               interests of the Convertible Noteholders;

         (b)   giving effect to any Extraordinary Resolution passed as provided
               in Article 7;

<PAGE>

                                      -40-

          (c)  making such provisions not inconsistent with this Indenture as
               may be necessary or desirable with respect to matters or
               questions arising hereunder, provided that such provisions are
               not, in the opinion of the Trustee, prejudicial to the rights or
               interests of any of the Convertible Noteholders;

          (d)  adding to or altering the provisions hereof in respect of the
               transfer of Convertible Notes, making provision for the exchange
               of Convertible Note Certificates and making any modification in
               the form of the Convertible Note Certificates which does not
               affect the substance thereof;

          (e)  modifying any of the provisions of this Indenture, including
               relieving the Corporation from any of the obligations, conditions
               or restrictions herein contained, provided that such modification
               or relief shall be or become operative or effective only if, in
               the opinion of the Trustee relying on the advice of Counsel, such
               modification or relief in no way prejudices any of the rights of
               the Convertible Noteholders or of the Trustee, and provided
               further that the Trustee may in its sole discretion decline to
               enter into any such supplemental indenture which in its opinion
               may not afford adequate protection to the Trustee when the same
               shall become operative;

          (f)  for any other purpose not inconsistent with the terms of this
               Indenture, including the correction or rectification of any
               ambiguities, defective or inconsistent provisions, errors,
               mistakes or omissions herein, provided that in the opinion of the
               Trustee the rights of the Trustee and of the Convertible
               Noteholders are in no way prejudiced thereby; and

          (g)  to evidence the assumption by any Successor Corporation of the
               obligations under this Indenture as provided in Section 8.2
               hereof.

8.2       Successor Corporations

          In the case of the consolidation, amalgamation, merger or transfer of
the undertaking or assets of the Corporation as an entirety or substantially as
an entirety to another Corporation ("Successor Corporation"), the Successor
Corporation resulting from such consolidation, amalgamation, merger or transfer
(if not the Corporation) shall expressly assume, by supplemental indenture
satisfactory in form to the Trustee and executed and delivered to the Trustee,
the due and punctual performance and observance of each and every covenant and
condition of this Indenture to be performed and observed by the Corporation.

                       ARTICLE 9 - CONCERNING THE TRUSTEE

9.1       Trust Indenture Legislation

          (a)  If and to the extent that any provision of this Indenture limits,
               qualifies or conflicts with a mandatory requirement of Applicable
               Legislation, such mandatory requirement shall prevail.

<PAGE>

                                      -41-

         (b)   The Corporation and the Trustee agree that each will, at all
               times in relation to this Indenture and any action to be taken
               hereunder, observe and comply with and be entitled to the
               benefits of Applicable Legislation.

9.2      Rights and Duties of Trustee

         (a)   In the exercise of the rights and duties prescribed or conferred
               by the terms of this Indenture, the Trustee shall act honestly
               and in good faith with a view to the best interests of the
               Convertible Noteholders and shall exercise that degree of care,
               diligence and skill that a reasonably prudent trustee would
               exercise in comparable circumstances. No provision of this
               Indenture shall be construed to relieve the Trustee from
               liability for its own negligent action, its own negligent failure
               to act, or its own wilful misconduct or bad faith.

         (b)   The obligation of the Trustee to commence or continue any act,
               action or proceeding for the purpose of enforcing any rights of
               the Trustee or the Convertible Noteholders hereunder shall be
               conditional upon the Convertible Noteholders furnishing, when
               required by notice by the Trustee, sufficient funds to commence
               or to continue such act, action or proceeding and an indemnity
               reasonably satisfactory to the Trustee to protect and to hold
               harmless the Trustee against the costs, charges and expenses and
               liabilities to be incurred thereby and any loss and damage it may
               suffer by reason thereof. None of the provisions contained in
               this Indenture shall require the Trustee to expend or to risk its
               own funds or otherwise to incur financial liability in the
               performance of any of its duties or in the exercise of any of its
               rights or powers unless indemnified as aforesaid.

         (c)   The Trustee may, before commencing or at any time during the
               continuance of any such act, action or proceeding, require the
               Convertible Noteholders, at whose instance it is acting to
               deposit with the Trustee the Convertible Notes held by them, for
               which Convertible Notes the Trustee shall issue receipts.

         (d)   Every provision of this Indenture that by its terms relieves the
               Trustee of liability or entitles it to rely upon any evidence
               submitted to it is subject to the provisions of Applicable
               Legislation, of this Section 9.2 and of Section 9.3.

9.3      Evidence, Experts and Advisers

         (a)   In addition to the reports, certificates, opinions and other
               evidence required by this Indenture, the Corporation shall
               furnish to the Trustee such additional evidence of compliance
               with any provision hereof, and in such form, as may be prescribed
               by Applicable Legislation or as the Trustee may reasonably
               require by written notice to the Corporation.

         (b)   In the exercise of its rights and duties hereunder, the Trustee
               may, if it is acting in good faith, rely as to the truth of the
               statements and the accuracy of the opinions expressed in
               statutory declarations, opinions, reports, written requests,
               consents, or orders of the Corporation, certificates of the
               Corporation or other evidence

<PAGE>

                                       -42-

               furnished to the Trustee pursuant to a request of the Trustee,
               provided that such evidence complies with Applicable Legislation
               and that the Trustee complies with Applicable Legislation and
               that the Trustee examines the same and determines that such
               evidence complies with the applicable requirements of this
               Indenture.

         (c)   Whenever it is provided in this Indenture or under Applicable
               Legislation that the Corporation shall deposit with the Trustee
               resolutions, certificates, reports, opinions, requests, orders or
               other documents, it is intended that the truth, accuracy and good
               faith on the effective date thereof and the facts and opinions
               stated in all such documents so deposited shall, in each and
               every such case, be conditions precedent to the right of the
               Corporation to have the Trustee take the action to be based
               thereon.

          (d)  Proof of the execution of an instrument in writing, including a
               Convertible Noteholders' Request, by any Convertible Noteholder
               may be made by the certificate of a notary public, or other
               officer with similar powers, that the Person signing such
               instrument acknowledged to it the execution thereof, or by an
               affidavit of a witness to such execution or in any other manner
               which the Trustee may consider adequate.

          (e)  The Trustee may employ or retain such Counsel, accountants,
               appraisers or other experts or advisers as it may reasonably
               require for the purpose of determining and discharging its duties
               hereunder and may pay reasonable remuneration for all services so
               performed by any of them, without taxation of costs of any
               Counsel, and shall not be responsible for any misconduct or
               negligence on the part of any such experts or advisers who have
               been appointed with due care by the Trustee. The Corporation
               shall pay or reimburse the Trustee for any reasonable
               remuneration, expenses, disbursements and advances of such
               Counsel, accountant, appraiser or other expert or advisor.

          (f)  The Trustee may act and rely and shall be protected in acting and
               relying in good faith on the opinion or advice of or information
               obtained from any counsel, accountant or other expert or advisor,
               whether retained or employed by the Corporation or by the
               Trustee, in relation to any matter arising in the administration
               of the trusts hereof.

9.4       Actions by Trustee to Protect Interest

          The Trustee shall have power to institute and to maintain such actions
and proceedings as it may consider necessary or expedient to preserve, protect
or enforce its interests and the interests of the Convertible Noteholders.

9.5       Trustee Not Required to Give Security

          The Trustee shall not be required to give any bond or security in
respect of the execution of the trusts and powers of this Indenture or otherwise
in respect of the premises.

<PAGE>

                                       -43-

9.6      Protection of Trustee

         Except as provided in Section 9.2, by way of supplement to the
provisions of any law for the time being relating to trustees it is expressly
declared and agreed as follows:

         (a)   the Trustee shall not be liable for or by reason of any
               statements of fact or recitals in this Indenture or in the
               Convertible Note Certificates (except the representation
               contained in Section 9.8 or in the certificate of the Trustee on
               the Convertible Note Certificates) or be required to verify the
               same, but all such statements or recitals are and shall be deemed
               to be made by the Corporation;

         (b)   nothing herein contained shall impose any obligation on the
               Trustee to see to or to require evidence of the registration or
               filing (or renewal thereof) of this Indenture or any instrument
               ancillary or supplemental hereto;

         (c)   the Trustee shall not incur any liability or responsibility
               whatsoever, or be in any way responsible for the consequence of
               any breach on the part of the Corporation of any of the covenants
               herein contained or of any acts of any directors, officers,
               employees, agents or servants of the Corporation; and

         (d)   the Corporation hereby indemnifies and saves harmless the Trustee
               and its officers, directors and employees from and against any
               and all liabilities, losses, costs, actions, or demands
               whatsoever which may be brought against the Trustee or which it
               may suffer or incur as a result of or arising out of the
               performance of its duties and obligations under this Indenture,
               save only in the event of the negligent action, the negligent
               failure to act or the wilful misconduct or bad faith of the
               Trustee. It is understood and agreed that this indemnification
               shall survive the termination or discharge of this Indenture or
               the resignation or removal of the Trustee.

9.7      Replacement of Trustee; Successor by Merger

         (a)   The Trustee may resign its trust and be discharged from all
               further duties and liabilities hereunder, subject to this Section
               9.7, by giving to the Corporation not less than 30 days prior
               notice in writing or such shorter prior notice as the Corporation
               may accept as sufficient. The Convertible Noteholders by
               Extraordinary Resolution shall have power at any time to remove
               the existing Trustee and to appoint a new trustee. In the event
               of the Trustee resigning or being removed as aforesaid or being
               dissolved, becoming bankrupt, going into liquidation or otherwise
               becoming incapable of acting hereunder, the Corporation shall
               forthwith appoint a new trustee unless a new trustee has already
               been appointed by the Convertible Noteholders; failing such
               appointment by the Corporation, the retiring Trustee at the
               Corporation's expense or any Convertible Noteholder may apply to
               a justice of the Ontario Superior Court of Justice on such notice
               as such justice may direct, for the appointment of a new trustee;
               but any new trustee so appointed by the Corporation or by the
               Court shall be subject to removal as aforesaid by the Convertible
               Noteholders. Any new trustee appointed

<PAGE>

                                       -44-

               under any provision of this Section 9.7 shall be a corporation
               authorized to carry on the business of a trust company in the
               Qualifying Jurisdictions and, if required by the Applicable
               Legislation for any other provinces, in such other provinces. On
               any such appointment the new trustee shall be vested with the
               same powers, rights, duties and responsibilities as if it had
               been originally named herein as trustee under this Indenture.

         (b)   Upon the appointment of a successor trustee, the Corporation
               shall promptly notify the Convertible Noteholders thereof in the
               manner provided for in Section 10.2 hereof.

         (c)   Any corporation into or with which the Trustee may be merged or
               consolidated or amalgamated, or any corporation resulting
               therefrom to which the Trustee shall be a party, or any
               corporation succeeding to the trust business of the Trustee shall
               be the successor to the Trustee hereunder without any further act
               on its part or any of the parties hereto, provided that such
               corporation would he eligible for appointment as a successor
               trustee under subsection 9.7(a).

         (d)   Any Convertible Note Certificates certified but not delivered by
               a predecessor trustee may be certified and delivered by the
               successor trustee in the name of the predecessor or successor
               trustee.

9.8      Conflict of Interest

         (a)   The Trustee represents to the Corporation that at the time of
               execution and delivery hereof no material conflict of interest
               exists between its role as a trustee hereunder and its role in
               any other capacity and agrees that in the event of a material
               conflict of interest arising hereafter it will, within 90 days
               after ascertaining that it has such material conflict of
               interest, either eliminate the same or assign its trust hereunder
               to a successor trustee approved by the Corporation and meeting
               the requirements set forth in subsection 9.7(a). Notwithstanding
               the foregoing provisions of this subsection 9.8(a), if any such
               material conflict of interest exists or hereafter shall exist,
               the validity and enforceability of this Indenture and the
               Convertible Note Certificate shall not be affected in any manner
               whatsoever by reason thereof.

         (b)   Subject to subsection 9.8(a), the Trustee, in its personal or any
               other capacity, may buy, lend upon and deal in securities of the
               Corporation and generally may contract and enter into financial
               transactions with the Corporation or any Subsidiary of the
               Corporation without being liable to account for any profit made
               thereby.

9.9      Acceptance of Trust

         The Trustee hereby accepts the trusts in this Indenture declared and
provided for and agrees to perform the same upon the terms and conditions herein
set forth.

<PAGE>

                                       -45-

9.10     Trustee Not to be Appointed Receiver

         The Trustee and any Person related to the Trustee shall not be
appointed a receiver, a receiver and manager or liquidator of all or any part of
the assets or undertaking of the Corporation.

                              ARTICLE 10 - GENERAL

10.1     Notice to the Corporation and the Trustee

         (a)   Unless herein otherwise expressly provided, any notice to be
               given hereunder to the Corporation or to the Trustee shall be
               deemed to be validly given if delivered, sent by registered
               letter, postage prepaid or telecopied:

               If to the Corporation:

                           Certicom Corp
                           25801 Industrial Blvd.
                           Hayward, California 94545 U.S.A.

                           Telecopy:        (510) 780-5401
                           Attention:       President

               If to the Trustee:

                           Computershare Trust Company of Canada
                           100 University Avenue
                           11th Floor
                           Toronto, Ontario
                           M5J 2Y1

                           Telecopy:        (416) 981-9777
                           Attention:       Manager, Corporate Trust Department

               and any such notice delivered in accordance with the foregoing
               shall be deemed to have been received on the date of delivery or,
               if mailed, on the third Business Day following the date of the
               postmark on such notice or, if telecopied, on the next Business
               Day following the date of transmission provided that its contents
               are transmitted and received completely and accurately.

         (b)   The Corporation or the Trustee, as the case may be, may from time
               to time notify the other in the manner provided in this Section
               10.1 of a change of address which, from the effective date of
               such notice and until changed by like notice, shall be the
               address of the Corporation or the Trustee, as the case may be,
               for all

<PAGE>

                                       -46-

                  purposes of this Indenture. A copy of any notice of change of
                  address given pursuant to this subsection 10.1(b) shall be
                  sent to the Convertible Note Agency, and shall be available
                  for inspection by Convertible Noteholders during normal
                  business hours.

         (c)      If, by reason of a strike, lockout or other work stoppage,
                  actual or threatened, involving postal employees, any notice
                  to be given to the Trustee or to the Corporation hereunder
                  could reasonably be considered unlikely to reach its
                  destination, such notice shall be valid and effective only if
                  it is delivered or sent by telecopy or other means of prepaid,
                  transmitted and recorded communication.

10.2     Notice to Convertible Noteholders

         (a)      Any notice to the Convertible Noteholders under the provisions
                  of this Indenture shall be valid and effective if delivered or
                  sent by ordinary mail addressed to such holders at their post
                  office addresses appearing on the register of holders
                  maintained by the Trustee and shall be deemed to have been
                  effectively given on the date of delivery or, if mailed, on
                  the third Business Day following the date of the postmark on
                  such notice.

         (b)      If, by reason of a strike, lockout or other work stoppage,
                  actual or threatened, involving postal employees, any notice
                  to be given to the Convertible Noteholders hereunder could
                  reasonably be considered unlikely to reach its destination,
                  such notice shall be valid and effective only if it is
                  delivered or is published twice in the Report on Business
                  section of the Globe and Mail newspaper.

10.3     Ownership of Convertible Notes

         The Corporation and the Trustee may deem and treat the registered owner
of any Convertible Notes as the absolute owner thereof for all purposes, and the
Corporation and the Trustee shall not be affected by any notice or knowledge to
the contrary except where the Corporation or the Trustee is required to take
such notice by statute or by order of a court of competent jurisdiction. A
Convertible Noteholder shall be entitled to the rights evidenced by the
Convertible Notes held by such holder free from all equities or rights of set
off or counterclaim between the Corporation and the original or any intermediate
holder of the Convertible Notes and all Persons may act accordingly. The receipt
by any such Convertible Noteholder of the Convertible Debentures which may be
acquired pursuant to the exercise of Convertible Notes held by such holder,
shall be a good discharge to the Corporation and the Trustee for the same and
neither the Corporation nor the Trustee shall be bound to inquire into the title
of any such holder except where the Corporation or the Trustee is required to
take such notice by statute or by order of a court of competent jurisdiction.

10.4     Evidence of Ownership

         (a)      Upon receipt of a certificate of any bank, trust company or
                  other depositary satisfactory to the Trustee stating that the
                  Convertible Note Certificates specified therein have been
                  deposited by a named Person with such bank, trust company or
                  other depositary and will remain so deposited until the expiry
                  of the period

<PAGE>

                                       -47-

                  specified therein, the Corporation and the Trustee may treat
                  the Person so named as the owner thereof, and such certificate
                  as sufficient evidence of the ownership by such Person of the
                  Convertible Notes represented thereby during such period, for
                  the purpose of any requisition, direction, consent, instrument
                  or other document to be made, signed or given by the holder of
                  the Convertible Note Certificate so deposited.

         (b)      The Corporation and the Trustee may accept as sufficient
                  evidence of the fact and date of the signing of any
                  requisition, direction, consent, instrument or other document
                  by any Person, by (i) the signature of any officer of any
                  bank, trust company, or other depositary satisfactory to the
                  Trustee as witness of such execution, (ii) the certificate of
                  any notary public or other officer authorized to take
                  acknowledgments of deeds to be recorded at the place where
                  such certificate is made that the Person signing acknowledged
                  to him the execution thereof, (iii) a satisfactory statutory
                  declaration of a witness of such execution, or (iv) any other
                  documentation satisfactory to the Corporation and the Trustee.

10.5     Counterparts

         This Indenture may be executed in several counterparts, each of which
when so executed shall be deemed to be an original and such counterparts
together shall constitute one and the same instrument and notwithstanding their
date of execution they shall be deemed to be dated as of the date hereof.

10.6     Satisfaction and Discharge of Indenture

         Upon the earlier of:

         (a)      the date by which there shall have been delivered to the
                  Trustee for exercise or destruction all Convertible Note
                  Certificates theretofore certified hereunder; and

         (b)      the Time of Expiry;

and if all certificates representing Convertible Debentures required to be
issued in compliance with the provisions hereof have been issued and delivered
hereunder in accordance with such provisions this Indenture shall cease to be of
further effect and the Trustee, on demand of and at the cost and expense of the
Corporation and upon delivery to the Trustee of a certificate of the Corporation
stating that all conditions precedent to the satisfaction and discharge of this
Indenture have been complied with, shall execute proper instruments
acknowledging satisfaction and discharge of this Indenture. Notwithstanding the
foregoing, the indemnities provided to the Trustee by the Corporation hereunder
shall remain in full force and effect and survive the termination of this
Indenture.

10.7     Provisions of Indenture and Convertible Notes for the Sole Benefit of
         Parties and Convertible Noteholders

         Nothing in this Indenture or in the Convertible Note Certificates,
expressed or implied shall give or be construed to give to any Person other than
the parties hereto and the Convertible

<PAGE>

                                       -48-

Noteholders, as the case may be, any legal or equitable right, remedy or claim
under this Indenture, or under any covenant or provision herein or therein
contained, all such covenants and provisions being for the sole benefit of the
parties hereto and the Convertible Noteholders.

10.8     Convertible Notes Owned by the Corporation or its Subsidiaries -
         Certificate to be Provided

         For the purpose of disregarding any Convertible Notes owned legally or
beneficially by the Corporation or any Subsidiary of the Corporation as
contemplated in Section 7.16, the Corporation shall, upon the request of the
Trustee, provide to the Trustee, from time to time, a certificate of the
Corporation setting forth at the date of such certificate:

         (a)      the names (other than the name of the Corporation) of the
                  registered holders of Convertible Notes which, to the
                  knowledge of the Corporation, are owned by or held for the
                  account of the Corporation or any Subsidiary of the
                  Corporation; and

         (b)      the number of Convertible Notes owned by or held for the
                  account of the Corporation or any Subsidiary of the
                  Corporation;

and the Trustee, in making the computations in Section 7.16, shall be entitled
to rely on such certificate without any additional evidence.

10.9     Further Assurances

         The parties hereto and each of them do hereby covenant and agree to do
such things and execute such further documents, agreements and assurances as may
be necessary or advisable from time to time in order to carry out the terms and
conditions of this Indenture in accordance with their true intent.

10.10    Unenforceable Terms

         If any term, covenant or condition of this Indenture, or the
applicability thereof to any party or circumstance shall be invalid or
unenforceable to any extent, the remainder of this Indenture or application of
such term, covenant or condition to a party or circumstance other than those to
which it is held invalid or unenforceable shall not be affected thereby and each
remaining term, covenant or condition of this Indenture shall be valid and shall
be enforceable to the fullest extent permitted by law.

10.11    Governing Law

         This Indenture shall be governed by and construed in accordance with
the laws of the Province of Ontario and the laws of Canada applicable therein.
Each of the parties irrevocably attorns to the exclusive jurisdiction of the
courts of the Province of Ontario with respect to all matters arising out of
this Indenture and the transactions contemplated herein.

<PAGE>

                                       -49-

10.12    Enurement

         This Indenture shall benefit and bind the parties to it and their
respective successors and assigns.

         IN WITNESS WHEREOF the parties hereto have executed this Indenture
under the hands of their proper offices in that behalf on the day and year first
above written.

CERTICOM CORP.                              COMPUTERSHARE TRUST
                                            COMPANY OF CANADA

Per: ____________________________           Per: _______________________________


Per: ____________________________           Per: _______________________________

<PAGE>

                  THIS IS SCHEDULE "A" to the Convertible Note Indenture made as
                  of August 30, 2001 between Certicom Corp. and Computershare
                  Trust Company of Canada

                          CONVERTIBLE NOTE CERTIFICATE

                                 CERTICOM CORP.
                (Continued under the laws of the Yukon Territory)

CONVERTIBLE NOTE
CERTIFICATE NO._________
                                            ------------------------------------
                                             aggregate principal amount of
                                             CONVERTIBLE NOTES entitling the
                                             holder to acquire an aggregate
                                             principal amount of Convertible
                                             Debentures equal to the aggregate
                                             principal amount of the Convertible
                                             Notes represented hereby.

THE CONVERTIBLE NOTES REPRESENTED BY THIS CONVERTIBLE NOTE CERTIFICATE ARE
SUBJECT TO STATUTORY RESALE RESTRICTIONS UNDER THE APPLICABLE SECURITIES
LEGISLATION OF THE PROVINCE IN WHICH YOU RESIDE. IN THE EVENT THAT THE
CORPORATION IS UNABLE TO OBTAIN A RECEIPT FOR THE (FINAL) PROSPECTUS FROM THE
SECURITIES REGULATORY AUTHORITY OF THE PROVINCE IN WHICH YOU RESIDE, OR THAT THE
CONVERTIBLE NOTES ARE EXERCISED PRIOR TO THE ISSUANCE OF SUCH RECEIPT, THE
CONVERTIBLE DEBENTURES ISSUABLE ON EXERCISE OF THE CONVERTIBLE NOTES AND THE
COMMON SHARES ISSUABLE IN ACCORDANCE WITH THE TERMS OF THE CONVERTIBLE
DEBENTURES MAY BE SUBJECT TO STATUTORY RESALE RESTRICTIONS UNDER THE APPLICABLE
SECURITIES LEGISLATION OF THAT PROVINCE. A LEGEND TO THIS EFFECT MAY BE PLACED
ON CERTIFICATES EVIDENCING SUCH CONVERTIBLE DEBENTURES AND COMMON SHARES UNTIL
SUCH STATUTORY RESALE RESTRICTIONS ARE NO LONGER APPLICABLE IN THE SOLE
DISCRETION OF THE CORPORATION. YOU ARE ADVISED TO CONSULT YOUR OWN LEGAL
ADVISORS IN THIS REGARD.

                   THIS IS TO CERTIFY THAT FOR VALUE RECEIVED

________________________________________________________________________________
                                     (Name)

(hereinafter referred to as the "holder") is entitled to acquire in the manner
and subject to the terms hereof and of the Indenture (as hereinafter defined),
at any time and from time to time until 5:00 p.m. (Toronto time) (the "Time of
Expiry") on the date (the "Expiry Date") which is five Business Days following
the earlier of: (a) the date on which all required receipts for the Final
Prospectus are issued by the Securities Commissions relating to the distribution
of Convertible Debentures to the holders of Convertible Notes upon the exercise
of Convertible Notes; and (b)

<PAGE>

                                      -2-

August 30, 2002, Convertible Debentures due August 30, 2004 (the "Convertible
Debentures") of Certicom Corp. (the "Corporation"), issued under the Convertible
Debenture Trust Indenture made as of August 30, 2001 between the Corporation and
the Trustee, in an aggregate principal amount equal to the aggregate principal
amount of the Convertible Notes represented hereby exercised by the holder, for
each integral multiple of $1,000 of principal amount of Convertible Notes
represented hereby exercised by the holder.

         Upon issuance of the Convertible Notes represented hereby the aggregate
amount of funds paid for such Convertible Notes shall be paid to the Escrow
Agent.

         The right to acquire Convertible Debentures may only be exercised by
the holder within the time set forth above by:

         (a)  duly completing and executing the Exercise Form attached hereto;
              and

         (b)  surrendering this Convertible Note Certificate to the Trustee at
              the principal office of the Trustee in the City of Toronto.

         This Convertible Note Certificate shall be deemed to be surrendered
only upon personal delivery hereof to, or, if sent by mail or other means of
transmission, upon actual receipt hereof by, the Trustee at the office referred
to above.

         Upon due completion and execution of the Exercise Form and the
surrender of this Convertible Note Certificate in accordance with the terms and
conditions of the Indenture, the Person(s) in whose name the Convertible
Debentures issuable upon exercise of the Convertible Notes represented hereby
are to be issued shall be deemed for all purposes (except as provided in the
Indenture) to be the holder or holders of record of such Convertible Debentures
on the Exercise Date, and the Corporation has covenanted that it will (subject
to the provisions of the Indenture) cause certificates representing such
Convertible Debentures to be mailed or delivered to the Person or Persons at the
address or addresses specified in the Exercise Form within five Business Days.

         The registered holder of the Convertible Notes represented hereby may
acquire any lesser principal amount of Convertible Debentures than the aggregate
principal amount of the Convertible Notes represented by this Convertible Note
Certificate. In such event, the holder shall be entitled to receive a new
Convertible Note Certificate for the unexercised portion of the Convertible
Notes represented hereby. Convertible Debentures will only be issued in
denominations of $1,000 and multiples thereof.

         At the Time of Expiry on the Expiry Date, the Convertible Notes
represented hereby shall be deemed to have been exercised immediately prior to
the Time of Expiry (unless the Convertible Notes represented hereby have been
previously exercised) to convert such Convertible Notes into Convertible
Debentures and the certificates representing such Convertible Debentures will be
issued to the holder of this Convertible Note Certificate upon surrender to the
Trustee at the principal office of the Trustee in the City of Toronto and
thereupon the Convertible Notes represented hereby be deemed to be cancelled and
of no further force and effect. On the second Business Day following the Expiry
Date, the Corporation shall notify

<PAGE>

                                      -3-

holders of the Convertible Notes that if they have not exercised such
Convertible Notes prior to the Time of Expiry that such Convertible Notes have
been deemed to be exercised.

         The Convertible Notes represented by this certificate are issued under
and pursuant to a Convertible Note Trust Indenture (hereinafter referred to as
the "Indenture") made as of August 30, 2001 between the Corporation and the
Trustee. Reference is made to the Indenture and any instruments supplemental
thereto for a full description of the rights of the holder of this Convertible
Note Certificate and the terms and conditions upon which the Convertible Notes
are, or are to be, issued and held, with the same effect as if the provisions of
the Indenture and all instruments supplemental thereto were herein set forth. By
acceptance hereof, the holder assents to all provisions of the Indenture.
Capitalized terms used herein have the same meaning as in the Indenture, unless
otherwise defined herein. To the extent the terms and conditions set forth in
this Convertible Note Certificate conflict with the terms and conditions of the
Indenture, the Indenture shall prevail. The Corporation will furnish to the
holder of this Convertible Note Certificate, upon request and without charge, a
copy of the Indenture.

         The Convertible Notes represented hereby shall bear interest from the
Effective Date or the date of issue, whichever is later, at the rate of 7.25%
per annum, after as well as before default, with interest on overdue interest at
the same rate. Interest shall be based on a 365 or 366 day year, as the case may
be, and shall be calculated semi-annually not in advance from the Effective Date
or the date of issue of the Convertible Notes, whichever is later, or from the
last interest payment date to which interest has been paid or made available for
payment on the Convertible Notes, whichever is later, and shall be paid in like
money semi-annually on February 28 and August 30, commencing on February 28,
2002, unless this Convertible Note shall have been previously exercised as duly
provided for.

         As the interest on the Convertible Notes becomes due (except interest
payable at maturity which may be paid upon presentation and surrender of such
Convertible Notes for payment), the Corporation, either directly or indirectly
through the Trustee, shall forward or cause to be forwarded by prepaid ordinary
mail at least three (3) Business Days prior to the interest payment date, to the
holder for the time being, or, in the case of joint holders, to one of such
joint holders (failing written instructions to the contrary from all of such
joint holders), at the holder's address appearing on the register, a cheque for
such interest (less any tax required to be deducted), payable to or to the order
of such holder or holders and negotiable at par. The forwarding of such cheque
shall satisfy and discharge the liability for the interest upon the Convertible
Notes to the extent of the sums represented thereby (plus the amount of any tax
deducted as aforesaid) unless such cheque is not paid on presentation; provided
that in the event of the non-receipt of such cheque by such registered holder or
the loss or destruction thereof, the Corporation, upon being furnished with
reasonable evidence of such non-receipt, loss or destruction and indemnity
reasonably satisfactory to it, shall issue or cause to be issued to such
registered holder a replacement cheque for the amount of such cheque.

         If for any reason, the exercise of Convertible Notes in accordance with
the terms hereof is prohibited by law or does not take place as contemplated in
the Indenture (including by order of any securities regulatory authority or
court of competent jurisdiction) such Convertible Notes shall, notwithstanding
anything to the contrary herein contained, remain valid and outstanding,

<PAGE>

                                      -4-

and shall continue to accrue interest at the rate herein provided and shall be
due and payable in full on the sixth Business Day following the Expiry Date.

         The registered holder of this Convertible Note Certificate may, at any
time prior to the Time of Expiry, upon surrender hereof to the Trustee at its
principal office in the City of Toronto, exchange this Convertible Note
Certificate for other Convertible Note Certificates entitling the holder to
acquire, in the aggregate, the same aggregate principal amount of Convertible
Debentures as may be acquired on exercise of the Convertible Notes represented
by this Certificate.

         The holding of the Convertible Notes evidenced by this Convertible Note
Certificate shall not entitle the holder to any right or interest in respect of
the Corporation except as expressly provided in the Indenture and in this
Convertible Note Certificate.

         The Indenture provides that all holders of Convertible Notes shall be
bound by any resolution passed at a meeting of the holders held in accordance
with the provisions of the Indenture and resolutions signed by the holders of
Convertible Notes of 66"% of the principal amount of all then outstanding
Convertible Notes.

         Subject to the Corporation's right to purchase the Convertible Notes
under the Indenture and to any restriction under applicable law or policy of any
applicable regulatory body, the Convertible Notes evidenced by this Convertible
Note Certificate may be transferred on the register kept at the principal
offices of the Trustee in the City of Toronto by the registered holder hereof or
its legal representatives or its attorney duly appointed by an instrument in
writing in form and execution satisfactory to the Trustee, only upon compliance
with the conditions prescribed in the Indenture and upon compliance with such
reasonable requirements as the Trustee may prescribe.

         This Convertible Note Certificate shall not be valid for any purpose
whatever unless and until it has been certified by or on behalf of the Trustee.

<PAGE>

                                      -5-

         IN WITNESS WHEREOF the Corporation has caused this Convertible Note
Certificate to be signed by its duly authorized officer as of the 30th day of
August, 2001.

                                               CERTICOM CORP.

                                               Per:  ___________________________
                                                       President

                                               Per:  ___________________________

Certified by:


COMPUTERSHARE TRUST
COMPANY OF CANADA,
as Trustee



Per:   _________________________________






<PAGE>

                          TRANSFER OF CONVERTIBLE NOTES

   FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers to

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

$__________________________ principal amount of Convertible Notes of Certicom
Corp. registered in the name of the undersigned on the records of Certicom Corp.
maintained by Computershare Trust Company of Canada represented by the
Convertible Note Certificate attached hereto, together with any rights of action
for rescission or otherwise available to the undersigned, and irrevocably
appoints __________________________ the attorney of the undersigned to transfer
the said securities on the books or register with full power of substitution.

DATED ____________________________


__________________________________      ____________________________________
Signature Medallion Guaranteed          (Signature of Convertible Noteholder)

Instructions:

1.   Signature of the Convertible Noteholder must be the signature of the Person
     appearing on the face of this Convertible Note Certificate.

2.   If the Transfer Form is signed by a trustee, executor, administrator,
     curator, guardian, attorney, officer of a corporation or any Person acting
     in a fiduciary or representative capacity, the certificate must be
     accompanied by evidence of authority to sign satisfactory to the Trustee
     and the Corporation.

3.   The signature on the Transfer Form must be signature guaranteed by a
     Canadian chartered bank or a major Canadian trust company or by a medallion
     signature guarantee from a member of a recognized Medallion Signature
     Guarantee Program.

4.   Convertible Notes shall only be transferable in accordance with applicable
     laws. The transfer of Convertible Notes to a purchaser not resident in the
     Qualifying Jurisdictions (as defined in the Indenture under which the
     Convertible Notes represented by the Convertible Note Certificate have been
     issued) may result in the Convertible Debentures obtained upon the exercise
     of the Convertible Notes and the Common Shares obtained in accordance with
     the terms of the Convertible Debentures (whether after or before obtaining
     receipts for a final prospectus relating to the distribution of Convertible
     Debentures upon exercise of Convertible Notes in such Qualifying
     Jurisdictions) not being freely tradeable in the jurisdiction of the
     purchaser.

<PAGE>

                                  EXERCISE FORM

TO:       ______________________________________________________________________

AND TO:   ______________________________________________________________________


     The undersigned hereby exercises the right to acquire $___________________
principal amount of Convertible Debentures of Certicom Corp. in accordance with
and subject to the provisions of the Indenture referred to in the accompanying
Convertible Note Certificate.

THE SENIOR CONVERTIBLE UNSECURED SUBORDINATED DEBENTURES ARE TO BE ISSUED AS
FOLLOWS:

Name:                                          _________________________________
                                               (Print Clearly)

Address in Full:                               _________________________________

                                               _________________________________

Social Insurance Number:                       _________________________________

Aggregate Number of Convertible Debentures:    _________________________________

Note: If further nominees intended, please attach (and initial) schedule giving
these nominees.




DATED:   _____________________________


______________________________________     _____________________________________
Signature Medallion Guaranteed             Signature of Convertible Noteholder

______________________________________     Address in Full
Print Name in Full

                                           _____________________________________

<PAGE>

                  THIS IS SCHEDULE "B" to the Convertible Note Indenture made
                  as of August 30, 2001 between Certicom Corp. and Computershare
                  Trust Company of Canada

                                ESCROW DIRECTION

TO:  Computershare Trust Company of Canada (the "Escrow Agent")

     Reference is made to the Escrow and Custodial Agreement dated as of August
30, 2001 (the "Escrow Agreement") between Certicom Corp. (the "Corporation"),
Computershare Trust Company of Canada, as escrow agent, and Yorkton Securities
Inc. and to the Convertible Notes Trust Indenture dated as of August 30, 2001
(the "Indenture") between the Corporation and Computershare Trust Company of
Canada. Capitalized terms used, but not otherwise defined, herein shall have the
meanings given to them in the Indenture.

     The Corporation hereby represents and warrants that (i) it did not obtain a
Receipt prior to the Receipt Deadline, and (ii) pursuant to Redemption Election
Notices delivered to the Corporation in accordance with the terms of the
Indenture, the Corporation shall redeem, on the Redemption Date, [all/$.
aggregate principal amount] of the Convertible Notes at a price per Convertible
Note equal to the Redemption Price.

     The Corporation hereby irrevocably authorizes and directs the Escrow Agent
to deliver or cause to be paid to the Trustee the sum of $_____________ from the
Subscription Funds and to pay the balance of the Subscription Funds, if any, to
the Corporation.

     DATED: ______________________.

                                                  CERTICOM CORP.


                                                  Per:   _______________________
                                                         Name:
                                                         Title:






<PAGE>

                  THIS IS SCHEDULE "C" to the Convertible Note Indenture made
                  as of August 30, 2001 between Certicom Corp. and Computershare
                  Trust Company of Canada

                           REDEMPTION ELECTION NOTICE

TO:         Certicom Corp.
AND TO:     Computershare Trust Company of Canada

     Reference is made to the Convertible Notes Trust Indenture dated as of
August 30, 2001 (the "Indenture") between Certicom Corp. (the "Company") and
Computershare Trust Company of Canada. Capitalized terms used, but not otherwise
defined, herein shall have the meanings given to them in the Indenture.

     The undersigned hereby exercises the right to require the Corporation to
redeem, on the Redemption Date, all, but not less than all, of the Convertible
Notes registered in the name of the undersigned.

     The undersigned acknowledges and agrees that, in the event that Convertible
Noteholders representing in the aggregate more than 50% of the aggregate
principal amount of the Convertible Notes outstanding on September 28, 2001
elect to cause the Corporation to redeem the Convertible Notes held by such
Convertible Noteholders, the Convertible Notes held by the undersigned shall be
redeemed by the Corporation on the Redemption Date at a price per Convertible
Note equal to the Redemption Price.

     DATED: ___________________________.

_______________________________________    _____________________________________
Signature Medallion Guaranteed             Signature of Convertible Noteholder


_______________________________________    Address in Full
Print Name in Full
                                           _____________________________________

                                           _____________________________________