<PAGE>   1
                               EXPANSION AGREEMENT

        EXPANSION AGREEMENT, made and entered into this 26 day of November, 1997
by and between THE QUADRANT CORPORATION, a Washington corporation ("Developer"),
and OPTIVA CORPORATION, a Washington corporation ("Optiva").

                                    RECITALS

        A. Developer or its affiliate is the owner of that certain parcel of
land situated in the City of Snoqualmie, Washington, and being more particularly
described on Exhibit A hereto which parcel of Land includes approximately 11
acres ("Initial Land").

        B. Concurrently with the execution of this Agreement, Developer, as
Landlord, and Optiva, as Tenant, have entered into a Lease ("Initial Lease")
under which certain buildings to be constructed on the Initial Land by the
Landlord ("Initial Premises") will be leased to Optiva. Concurrently with the
Initial Lease, Developer, as Landlord, and Optiva, as Tenant, also entered into
a Construction Agreement for Lease, governing Landlord's construction of the
Building Shell and Tenant Improvements constituting the Initial Premises. As a
part of the Initial Lease, Landlord and Tenant also entered into an Option and
Real Estate Purchase and Sale Agreement ("Initial Premises Option Agreement'),
under which Tenant has the option to purchase the Initial Land and Initial
Premises. Under the Initial Premises Option Agreement, following Optiva's
purchase of the Initial Land upon exercise of such option, Developer would be
engaged as Construction Manager to complete construction of the Initial Premises
for Optiva, pursuant to a Construction Management Agreement to be entered into
upon closing of such purchase.

        C. The Initial Land is part of Developer's larger parcel of land,
approximately 122.67 acres in area, known as Snoqualmie Ridge Business Park
("Business Park"). Developer is processing its application for a Binding Site
Improvement Plan 1 for the Business Park, under City of Snoqualmie File No. BSIP
97-01 ("BSIP 1"). A copy of Developer's BSIP 1 application ("BSIP 1
Application") has been furnished to Optiva. Upon approval of the BSIP 1, the
Initial Land will become Lots 8 and 9 of the Business Park.

        D. Optiva desires to reserve the right to purchase all or part of, or
lease one or more buildings on, an approximately 1 0-acre parcel in the Business
Park adjacent to the Initial Land for expansion of its operations, and Developer
is willing to grant such right, all in accordance with the provisions of this
Agreement.

        E. Whether Optiva exercises its expansion rights under this Agreement or
not, Optiva desires certain assurances from Developer concerning the development
of the Business Park.


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                                   AGREEMENTS

        Developer and Optiva agree as follows:

        1.     Completion of Business Park; Noninterference.

               1.1 BSIP 1 Approval. Developer shall use diligent efforts to
obtain approval by the Snoqualmie City Council of the BSIP 1 for the Business
Park ("BSIP 1 Approval") in accordance with the BSIP 1 Application, subject to
minor adjustments. Following BSIP 1 Approval, Quadrant shall inform Optiva of
any proposed material changes to the BSIP 1 as approved, before any such changes
are finalized.

               1.2 Completion of Business Park Construction. Following BSIP 1
Approval, Developer shall complete development of the Business Park in
accordance with all requirements and conditions of the BSIP 1 and other
governmental requirements, and as otherwise determined by Developer, including
without limitation obtaining all further permits for work to be performed,
posting all governmentally required bonds to secure its development obligations,
and causing all required land development work to be completed. In particular,
Developer shall either complete or bond all required work before recordation of
the binding site plan for the Business Park in accordance with the BSIP 1
Approval. To the extent necessary for Optiva's occupancy of the Initial
Premises, Developer shall carry out such development completion obligations
under this Section 1.2 on or before Substantial Completion of the Initial
Premises. Developer shall maintain liability and casualty insurance covering the
risks attendant to its construction of the Business Park, with coverage and
terms and conditions as Developer deems prudent in view of the risks.

               1.3 Non-interference with Initial Premises. The Initial Premises
will be constructed while development and construction of the Business Park, as
described in Section 1.2, is in progress. Developer shall conduct all work
associated with the development of the Business Park in such a manner as is
calculated not to impede access to the Initial Premises after occupancy thereof
by Optiva, interrupt utility service to the Initial Premises, or materially
interfere with Optiva's operations in the Initial Premises, all at any time.

               1.4 Planned Interruptions. Following occupancy of the Initial
Premises by Optiva, Developer shall keep Optiva reasonably informed as to the
progress of Business Park construction activities. If Developer anticipates that
it will be necessary to interrupt utility service to the Initial Premises,
impede access to the Initial Premises, or interfere with Optiva's operations, in
each case because of such activities as, for example, excavation around existing
utilities serving the Initial Premises, grading and construction of roads and
access ways, and work on drainage systems ("Planned Interruption"), Developer
shall give Optiva as much advance notice as is reasonably practicable of the
Planned Interruption. Landlord shall use diligent efforts to accommodate
Optiva's expressed desires concerning any Planned Interruptions, and to minimize
the duration thereof. Any Planned Interruptions shall be carried out in
consultation and coordination with Optiva to the extent reasonably practicable.
No Planned Interruption shall result in liability to Developer of any kind,
provided the Planned Interruption proceeds as planned.

               1.5 Accidental Interruptions; Self-Help. Following occupancy of
the Initial Premises by Optiva, any events or circumstances in connection with
Developer's completion of the Business Park that interrupt utility service to
the Initial Premises, impede access to the 



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<PAGE>   3

Initial Premises, or interfere with Optiva's operations, other than a Planned
Interruption ("Accidental Interruption") shall be remedied by Developer (if the
Accidental Interruption is within Developer's control) as promptly as is
practicable under the circumstances. Optiva shall give prompt written notice to
Developer of any Accidental Interruptions. If (i) Developer fails to commence a
remedy of the Accidental Interruption within 3 days of Optiva's notice or (ii)
the interruption persists for 7 consecutive days after Optiva's notice (or if
Developer is using diligent and continuous efforts to correct the interruption,
then for such longer period as is reasonably necessary to correct the
interruption under such circumstances), then Optiva shall have the right to take
such actions as may be necessary to remedy the situation or attempt to cause the
utility purveyor to remedy the situation, as the case may be, and shall give
Developer contemporaneous notice of the actions it is taking. All costs and
expenses reasonably incurred by Optiva in so taking any such actions that are
the responsibility of Developer rather than the utility purveyor shall be
reimbursed by Developer within 30 days of invoice by Optiva.

               1.6 Emergency Action by Optiva. Nothing in Section 1.5 shall be
deemed to prohibit Optiva from acting alone to address any situation that Optiva
reasonably believes is an emergency that threatens to harm persons or property
if not acted upon immediately, provided that Optiva shall in good faith attempt
to contact Developer in advance of so acting to give Developer the first
opportunity to address the situation. If the emergency involves a matter over
which Developer has responsibility under this Agreement, Optiva shall be
entitled to reimbursement from Developer of the costs of so acting, up to the
amount of costs that Developer would reasonably have incurred if Developer had
acted instead. Such costs shall be reimbursed by Developer within 30 days of
invoice by Optiva.

               1.7 Business Park Zoning. Developer represents and warrants to
Optiva that the Initial Land and Expansion Land are zoned to permit development
of business park uses, pursuant to the Mixed Use Final Plan for Snoqualmie Ridge
dated September 15, 1995.

               1.8 Termination. Developer's obligations under this Section 1
shall terminate upon release of all performance bonds for Business Park
improvements maintained as a condition of BSIP 1 Approval.

               1.9 Coordinated Development. If Optiva becomes the owner of the
Expansion Land, Optiva shall cooperate with Developer as requested by Developer
to coordinate site development work on the Expansion Land and on the remainder
of Lots 10, 11 and 12. Such cooperation shall include, for example, sharing of
costs of joint grading, utility work and similar land development matters, in
each case where such joint work would be practicable and it appears that
efficiency would be enhanced and costs reduced by such cooperation. The costs of
such work shall be shared by the parties on an equitable basis to be agreed upon
that reflects the relative benefits to each party of such work; provided,
however, that Developer shall bear the entire cost of such work that is Business
Park construction for which Developer is responsible under Section 1.2.

               1.10 Shared Driveway and Utility Easement. If the Initial Land
and Initial Premises are purchased pursuant to the Initial Premises Option
Agreement, Optiva shall grant an easement for a shared driveway and utilities
between the Initial Land and Lot 10 of the Business Park, as shown on plans for
the Business Park that have been furnished to Optiva, containing reasonable
provisions for maintenance cost sharing and other typically covered 



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matters. To the extent that such easement is in place by the time of closing of
Optiva's acquisition of the Initial Land, the obligations under this Section
shall not apply.

        2.     Determination and Reservation of Expansion Land.

               2.1 Reservation. Developer shall initially reserve from (i) sale
to any other party, (11) development for lease to any other party, (iii)
development for speculative purposes or (iv) development for its own use,
proposed Lots 10, 11 and 12 in the Business Park, the legal description of which
proposed Lots is attached hereto as Exhibit B. The land to be reserved by
Developer shall be further defined and reduced as provided in this Agreement.
Such reservation shall be at no cost to Optiva.

               2.2 General Description of Expansion Land. The Expansion Land
shall consist of approximately ten contiguous acres located in proposed Lots 10,
11 and 12 of the Business Park, adjacent to the Initial Land, suitable for
development of expansion space for Optiva in size and design comparable to the
Initial Premises.

               2.3 Identification of Expansion Land. The size, location and
configuration of the Expansion Land within the requirements set forth in Section
2.2 shall be proposed by Developer at any time after March 1, 1998, and mutually
agreed upon by Developer and Optiva in good faith in a manner that assures to
the greatest extent possible the developability of the Expansion Land and of the
remaining lots in the Business Park. The parties shall use diligent efforts to
reach such agreement within 60 days after Developer's proposal. Any design or
engineering costs incurred with third parties selected by mutual agreement of
the parties in connection with the identification of the Expansion Land shall be
split equally between Developer and Optiva. The agreed Expansion Land shall be
subject to further agreed reduction in area following exercise of the Expansion
Option, as provided in Section 7.

               2.4 Term of Reservation. The term of Developer's reservation of
the Expansion Land shall be coterminous with the Option Term set forth in
Section 4.1.

               2.5 Developer's Use of Expansion Land. Developer's reservation of
land under this Section 2 shall not prevent Developer from using any or all of
Lots 10, 11 or 12 of the Business Park for any legal purpose, including without
limitation as a staging or storage area for Business Park construction, or for
rental to or use by others for any legal purposes.

        3. Optiva's Expansion Option. Developer grants to Optiva the option
("Expansion Option") either to:

               3.1 Expansion Lease. Lease ("Expansion Lease') one or more
buildings to be constructed by Developer on the Expansion Land ("Expansion
Premises"), which lease shall be accompanied by an option to purchase, all as
described in Section 5; or

               3.2 Expansion Purchase. Purchase the Expansion Land for
development and construction thereon by Optiva of the Expansion Premises, as
described in Section 6 ("Expansion Purchase").



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<PAGE>   5

        4.     Exercise; Option Term; Extensions.

               4.1 Manner of Exercise; Option Term. Optiva shall exercise the
Expansion Option, if at all, by notice to Developer ("Exercise Notice") on or
before January 1, 1999 (as it may be extended under Section 4.2, "Option Term").
The Exercise Notice shall specify either that Optiva is exercising its option
for Expansion Lease, or that Optiva is exercising its option for Expansion
Purchase.

               4.2 Extension of Option Term. Optiva shall have the right to
extend the Option Term until as late as June 30, 1999. Optiva shall exercise
such right, if at all, on a monthly basis by notifying Developer on or before
the expiration of the Option Term, as it may have been previously extended, that
it desires to extend the Option Term. Such notice shall be accompanied by a cash
extension payment to Developer in the amount of $25,000 for each of January
1999, February 1999 and March 1999, and $50,000 for each of April 1999, May 1999
and June 1999 ("Extension Payments') whereupon the Option Term shall be extended
until the end of such month.

               4.3 Applicability of Extension Payments. The entire amount of the
Extension Payments for January and February and 50% of the Extension Payments
for March, April, May and June shall be applied to the base monthly rent for any
Expansion Lease or to the purchase price at closing if Optiva exercises its
option for Expansion Purchase.

               4.4 Nonrefundability of Extension Payments. Extension Payments
are compensation to Developer for the reservation of the Expansion Land under
Section 2, and shall be nonrefundable and fully earned by Developer when made.

               4.5 Termination of Expansion Option. If no Exercise Notice is
given before the expiration of the Option Term, as it may have been extended, or
if Optiva notifies. Developer that it will not exercise the Expansion Option,
the Expansion Option will lapse and terminate, and Developer's obligation to
reserve the Expansion Land shall terminate.

               4.6 Nonexercisability of Expansion Option on Default. In the
event of any such Default by Optiva (following the expiration of any cure
periods without cure) under the Initial Lease, Construction Agreement for Lease
of the Initial Premises, Initial Premises Option Agreement, or Construction
Management Agreement for the Initial Premises, Developer shall have the right to
terminate the Expansion Option by notice to Optiva, whether the Expansion Option
has already been exercised or not.

        5. Expansion Lease. If Optiva exercises its option for an Expansion
Lease:

               5.1 Expansion Lease Documents. Developer and Optiva shall enter
into a Lease, Construction Agreement for Lease, and Option to Purchase and Real
Estate Purchase and Sale Agreement with Construction Management Agreement
substantially in the same form as the form of such documents entered into in
connection with the Initial Lease, except as otherwise provided in this Section
5 and as otherwise agreed at the time. Such documents shall be entered into
within 90 days after the Exercise Notice.

               5.2 Delay Provisions. Provisions of the Construction Agreement
for Lease concerning the consequences of delay by either Optiva or Developer
shall be negotiated in good faith to reflect the parties' circumstances at the
time.



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<PAGE>   6

               5.3 Basis for Determination of Rent. The amount of base monthly
rent shall be based on a return of capital formula (including all Project Costs
including the Expansion Land at $9.00 per gross square foot of the actual land
area as measured to the internal Business Park road rights-of-way and the
boundary between Lots 9 and 10, as shown on the BSIP 1) and developer fee
schedule negotiated by the parties in good faith. Notwithstanding the foregoing,
Project Costs for purposes of this subsection shall not include the cost of land
development of the Business Park as required to be completed by Developer under
Section 1.2 (e.g., roads, access ways, common improvements, detention ponds, and
all utilities stubbed to the Expansion Land).

               5.4 Rent Adjustment; Application of Extension Payments. Rent
shall be subject to CPI adjustment in the manner negotiated by the parties. To
the extent provided in Section 4, Extension Payments shall be applied against
base monthly rent as it becomes due under the Expansion Lease.

               5.5 Building Shell and Tenant Improvements Plans. The building
shell and tenant improvements of the Expansion Premises shall be designed by a
mutually approved architect and constructed by a mutually approved general
contractor selected by competitive bidding or by negotiation. The building shell
and tenant improvements plans and construction documents shall be subject to
mutual agreement of the parties and shall be consistent with the Design
Guidelines and Development Standards under the CC&R's and the Snoqualmie Ridge
Council Declaration. All estimated building shell and tenant improvements
construction costs shall be fully disclosed to and approved by Optiva.

               5.6 No Excluded Areas. The Expansion Lease will not include
provision for portions of the Expansion Premises to be constructed separately
from the Premises or excluded from the rentable area of the Premises.

               5.7 Tenant's Option to Purchase. Optiva shall have the option to
purchase the Expansion Land, exercisable around the time of commencement of
construction of the Expansion Premises, in which event Developer would be
engaged as Construction Manager to complete construction of the Premises. Such
option shall be governed by an Option and Real Estate Purchase and Sale
Agreement and Construction Management Agreement to contain terms negotiated by
the parties generally along the lines of such documents for the Initial Lease.
No Completion Guaranty shall be required to be provided by Developer or any of
its affiliates.

               5.8 Pricing; Payment. If Optiva exercises its option to purchase
under the Option and Real Estate Purchase and Sale Agreement entered into in
connection with the Expansion Lease, the purchase price shall include the
Expansion Land at $9.00 per gross square foot of the actual land area as
measured to the internal Business Park road rights-of-way and the boundary
between Lots 9 and 10, as shown on the BSIP 1). The Construction Management
Agreement shall provide for payment by Optiva to Developer of the Building Value
on a percentage of completion basis substantially in the same manner as in the
Construction Management Agreement entered into in connection with the Initial
Lease. The Building Value shall be a fixed amount stated in the Construction
Management Agreement reflecting the agreed value of the Expansion Land and
Expansion Premises upon completion, which amount shall be negotiated by the
parties on a capitalization of income basis, based on a hypothetical rent
determined using a return on capital formula. There shall be no limitation on
Developer's profit under the Construction Management Agreement.



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        6. Expansion Purchase. If Optiva exercises its option for Expansion
Purchase:

               6.1 Expansion Purchase Documents. Developer and Optiva shall
enter into a Real Estate Purchase and Sale Agreement substantially in the same
form as the form of the purchase and sale provisions of the Option and Purchase
and Sale Agreement entered into for the Initial Lease, except as otherwise
provided in this Section 6 and as otherwise agreed at the time.

               6.2 Pricing; Payment. If Optiva exercises its Expansion Purchase
option, the purchase price for the Expansion Land shall be $9.00 per gross
square foot of actual land area, as measured to the abutting road rights-of-way,
the boundary between Lots 9 and 10, as shown on the BSIP 1, and any other Lot
boundary.

               6.3 Condition of Expansion Land. At closing of the Expansion
Land, Developer shall deliver the Expansion Land substantially in the condition
depicted in the grading plan for the Business Park, with erosion control in
place in the manner deemed prudent by Developer, with required utilities stubbed
to the Lot lines, and with no Hazardous Substances, as defined in the Initial
Lease, other than as may be present on the Expansion Land on the date of
execution of this Agreement.

               6.4 Construction Management by Quadrant. Concurrently with the
Real Estate Purchase and Sale Agreement, at Optiva's election Optiva and
Quadrant shall also enter into a Construction Management Agreement under which
Quadrant shall be engaged on a fee basis to manage the construction of the
Expansion Premises for Optiva. Such Construction Management Agreement shall
contain terms and conditions consistent with this Agreement and otherwise as
negotiated by the parties in good faith. Optiva shall enter into all
construction contracts directly, and such construction shall be at Optiva's sole
cost and risk. If Optiva does not elect to enter into a Construction Management
Agreement with Quadrant, then Optiva shall pay Quadrant $50,000 at closing of
the purchase and sale of the Expansion Land, as compensation for Quadrant's lost
opportunity to serve as construction manager.

               6.5 Construction Management Fee. Quadrant's construction
management fee shall be 5% of the first $5,000,000 of actual direct construction
costs and 4% of all other actual direct construction costs.

               6.6    Rights of First Opportunity and First Refusal.

                      6.6.1 From and after the closing of Optiva's purchase of
               the Expansion Land, Developer shall have a right of first
               opportunity and a right of first refusal to repurchase the
               Expansion Land from Optiva, as provided in this Section 6.6.
               References to "Expansion Land" in this Section 6.6 refer to all
               or any portion of the Expansion Land.

                      6.6.2 From and after the closing of Optiva's purchase of
               the Expansion Land, Developer shall have the exclusive, first
               opportunity to purchase the Expansion Land in the event Optiva
               intends to sell the Expansion Land ("Right of First
               Opportunity"). Before listing the Expansion Land for sale, or
               offering to sell or soliciting offers to buy the Expansion Land,
               Optiva shall give Developer written notice ("Right of First
               Opportunity Notice") that Optiva intends to sell the Expansion
               Land.



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                      6.6.3 Within seven days after the Right of First
               Opportunity Notice, Developer may make an offer to purchase the
               Expansion Land by written notice to Optiva ("Developer Offer").
               If Developer does not make such an offer the Rights of First
               Opportunity and First Refusal shall both terminate and be of no
               further force or effect. If a Developer Offer is made and
               accepted, the parties shall proceed in accordance with the
               Developer Offer.

                      6.6.4 If the Developer Offer is made but not accepted,
               Optiva may list the Expansion Land for Sale, or offer to sell or
               solicit offers to buy the Expansion Land, or may negotiate with
               Developer, subject to Developer's Right of First Refusal.

                      6.6.5 Developer shall have an ongoing right of first
               refusal ("Right of First Refusal") with respect to any bona fide
               offer that Optiva accepts (conditional on the Right of First
               Refusal), as evidenced by a signed letter of intent or purchase
               and sale agreement. However, if such bona fide offer is made
               after Developer has made a Developer Offer, such offer shall be
               subject to the Right of First Refusal only if the total
               consideration to be paid to Optiva under such offer is an amount
               that is less than or equal to 95% of the total consideration set
               forth in the Developer Offer. If such consideration exceeds such
               amount, Optiva may proceed to sell the Expansion Land pursuant to
               such offer, free of the Right of First Refusal.

                      6.6.6 If the bona fide offer is subject to the Right of
               First Refusal, Optiva shall notify Developer in writing, which
               notice shall include a complete copy of such offer. Within five
               business days after such notice, Developer may elect by notice to
               Optiva to purchase the Expansion Land on the same terms as in the
               bona fide offer, including any feasibility or due diligence
               period provisions. In the event of such election, Developer shall
               purchase and Optiva shall sell the Expansion Land under the terms
               and subject to the conditions of the subject offer. If the
               purchase and sale does not close for any reason other than a
               default by Developer, the Expansion Land shall remain subject to
               the Right of First Opportunity and Refusal unless they have
               otherwise terminated under this Section 6.6.

                      6.6.7 The Rights of First Opportunity and First Refusal
               shall not apply to the following sales of the Expansion Land:

                             6.6.7.1 A sale of the Expansion Land together with
                      the Initial Land and Initial Premises;

                             6.6.7.2 A sale of the Expansion Land to an
                      affiliate of Optiva (or its assigns) that is regularly
                      engaged in commercial real estate development or
                      construction; or

                             6.6.7.3 A sale of the Expansion Land to a third
                      party developer for build-to-suit construction for Optiva
                      or its assigns).

                      6.6.8 The Right of First Opportunity and Right of First
               Refusal shall terminate upon commencement of construction of one
               or more buildings on the 



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               Expansion Land, or on the expiration of three years after the
               closing of the sale of the Expansion Land to Optiva, whichever
               occurs first. The Right of First Refusal shall apply to bona
               fide offers received by Optiva before such termination date.

               6.7 Timing of Expansion Purchase Documents. The Real Estate
Purchase and Sale Agreement, Construction Management Agreement, and the Rights
of First Opportunity and First Refusal Agreement shall be entered into within 60
days after the Exercise Notice.

        7. Size of Expansion Premises and Expansion Land. The Expansion Premises
shall contain at least 50,000 square feet of gross building area, and otherwise
shall be sized by Developer and Optiva as part of the agreement on Expansion
Lease documents or Expansion Purchase documents, as applicable, to fulfill
Optiva's expansion objectives within applicable legal requirements. Within 30
days following exercise of the Expansion Option, the Expansion Land size shall
be finalized by agreement of Developer and Optiva to a size, not less than three
acres, as reasonably accommodates the Expansion Premises in accordance with the
CC&R's, the Snoqualmie Ridge Council Declaration, and applicable legal
requirements and, if necessary, Developer shall cause the lot lines of the
Business Park to be adjusted accordingly.

        8. Effect of Failure to Agree. Upon exercise of the Expansion Option,
Optiva and Developer shall negotiate exclusively, diligently and in good faith
with one another concerning the terms of the required documents. If, despite
such good faith efforts, Optiva and Developer do not agree on the terms of
definitive documents consistent with this Agreement within 90 days after
exercise of the Expansion Option, either Developer or Optiva may terminate
negotiations by notice to the other, whereupon this Agreement shall terminate
and neither party shall have any further obligation to the other hereunder. If
Optiva has exercised the Expansion Option for Expansion Lease and the parties
are unable to agree on the terms of definitive documents within 60 days, Optiva
may exercise the Expansion Option for Expansion Purchase at any time before the
expiration of 90 days after exercise of the Expansion Option for Expansion
Lease.

        9. Assignment. This Agreement may be assigned by Optiva, but only as
part of an assignment of the Initial Lease or, if Optiva purchases the Initial
Premises pursuant to the Option and Real Estate Purchase and Sale Agreement, in
connection with Optiva's subsequent sale of the Initial Premises. This Agreement
shall be assigned to the assignee in the event of any permitted assignment of
the Initial Lease, or to the purchaser of the Initial Premises in the event
Optiva exercises its option to purchase and subsequently sells the Initial
Premises. This Agreement may be assigned by Developer to any entity to whom
Developer sells or transfers the Business Park and the right and responsibility
to complete development and construction of the Business Park. Upon any such
assignment by Developer, such purchasing or transferee entity shall assume the
obligations of Developer under this Agreement, whereupon Developer shall be
relieved of further responsibility hereunder. Notwithstanding the foregoing, the
right to serve as Construction Manager for the Expansion Premises in the event
the Expansion Purchase option is exercised shall remain with Quadrant.

        10. Recordation. A Memorandum of this Agreement shall be recorded
against the property described on Exhibit B on a mutually agreeable form, and
such memorandum shall among other things include references to the Rights of
First Opportunity and Refusal as



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<PAGE>   10

provided in Section 6.6. Upon identification of the Expansion Land under Section
2.3, such Memorandum shall be recorded only against the Expansion Land and shall
otherwise be released. Such Memorandum shall remain of record following closing
of Optiva's purchase of the Expansion Land. Such Memorandum shall be released if
the Expansion Option is not exercised by the expiration of the Option Term, as
it may be extended in accordance herewith. This Agreement shall not be recorded.

        11. Real Estate Commissions. In the event the Expansion Option is
exercised, Landlord shall pay a real estate commission to Colliers Macaulay
Nicolls International pursuant to a commission agreement dated September 30,
1997 between Colliers Macaulay Nicolls International and Quadrant.

        12. Prior Agreements. This Agreement, together with the Initial Lease,
Construction Agreement for Lease, Option and Real Estate Purchase and Sale
Agreement and Construction Management Agreement for the Initial Land and Initial
Premises, contains all of the agreements of the parties with respect to the
matters covered by this Agreement, and no prior agreements or understandings
pertaining to any such matters shall be effective for any purpose. Without
limiting the foregoing, the Letter of Intent dated July 9, 1997 concerning the
Initial Lease and the matters covered hereby is superseded and of no further
force or effect with respect to the matters covered hereby.

        13. Attorneys' Fees. In the event of any litigation, arbitration or
other proceeding (including proceedings in bankruptcy and probate and on appeal)
brought to enforce or interpret or otherwise arising under this Agreement, the
substantially prevailing party therein shall be entitled to the award of its
reasonable attorneys' fees, witness fees, and court costs incurred therein and
in preparation therefor.

        14. Notices. All notices and demands which may or are to be required or
permitted to be given under this Lease shall be in writing and if personally
delivered shall be effective when received. If mailed, a notice shall be deemed
effective on the third day after deposited as registered or certified mail,
postage prepaid, directed to the other party. Notices shall be delivered or
mailed to the parties at the following addresses:

If to Developer:                     If to Optiva:
----------------                     -------------

The Quadrant Corporation             Optiva Corporation
Quadrant Plaza, Suite 500            13222 SE 30th Street
NE 8th Street at 112th Ave. NE       Bellevue, WA 98005
Bellevue, WA 98004                   Attn:  Karl Forsgaard, Corporate Counsel
Tel:  425-455-2900                   Tel:  425-401-2307
Fax:  425-646-8300                   Fax:  425-401-4824
Attn:  Commercial Division
                                     with a copy to:

                                     Gordon W.  Tanner
                                     Stoel Rives LLP
                                     600 University Street, Suite 3600
                                     Seattle, WA 98101-3197
                                     Tel:  206-624-0900
                                     Fax:  206-386-7500



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<PAGE>   11

Either party may change its address for notices by at least 15 days' advance
written notice to the other.

        15. Exhibits. The Exhibits hereto are made a part of and incorporated
into this Agreement.

        16. Modification. Neither this Agreement nor any provision hereof may be
waived, modified, amended, discharged or terminated except as provided herein or
by an instrument in writing signed by the party against which the enforcement of
such waiver, modification, amendment, discharge or termination is sought, and
then only to the extent set forth in such instrument.

        17. Applicable Law. This Agreement shall be governed by, and construed
in accordance with, the laws of the State of Washington. Venue for any action to
enforce or interpret this Agreement shall lie in the Superior Court of King
County, Washington. All sums referred to in this Agreement shall be calculated
by and payable in the lawful currency of the United States.

        18. Headings. Descriptive headings are used in this Agreement for
convenience only and shall not control, limit, amplify or otherwise modify or
affect the meaning or construction of any provision of this Agreement.

        19. Binding Effect. This Agreement shall be binding upon and shall inure
to the benefit of the parties hereto and their respective permitted heirs,
successors and assigns.

        20. Capitalized Terms. Capitalized terms not otherwise defined in this
Agreement shall have the meanings ascribed to them in the Initial Lease or the
Construction Agreement for Lease, Option and Real Estate Purchase and Sale
Agreement or Construction Management Agreement for the Initial Land and Initial
Premises.

        21. Waiver. The failure of either party at any time to require
performance of any provision of this Agreement shall not limit the party's right
to enforce such provision. Waiver of any breach of any provision shall not be a
waiver of any succeeding breach of the provision or a waiver of the provision
itself or any other provision.

        22. Description of Transaction. This Agreement creates only the
relationship of seller and buyer and no joint venture, partnership or other
joint undertaking is intended hereby, and neither party hereto shall have any
rights to make any representations or incur any obligations on behalf of the
other. Neither party has authorized any agent to make any representations, admit
any liability or undertake any obligation on its behalf. Neither party is
executing this Agreement on behalf of an undisclosed principal, and no third
party is intended to be benefited by this contract.

        23. Time of Essence; Business Day. Time is of the essence of this
Agreement and of each covenant and agreement that is to be performed at a
particular time or within a particular period of time. However, if the final
date of any period which is set out in any provision of this Agreement falls on
a Saturday, Sunday or legal holiday under the laws of the United States, or the
State of Washington, then the time of such period, as the case may be, shall be
extended to the next date which is not a Saturday, Sunday or legal holiday.



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<PAGE>   12

        24. Invalid Provision. If any provision of this Agreement is held to be
illegal, invalid or unenforceable under present or future laws, such provision
shall be fully severable; this Agreement shall be construed and enforced as if
such illegal, invalid or unenforceable provision had never comprised a part of
this Agreement; and the remaining provisions of this Agreement shall remain in
full force and effect and shall not be affected by such illegal, invalid or
unenforceable provision or by its severance from this Agreement.

        25. Cooperation. The parties shall cooperate in good faith with one
another and shall use diligent efforts to carry out the intent and provisions of
this Agreement.

        EXECUTED as of the date first above written.

                                   DEVELOPER:

                                     THE QUADRANT CORPORATION



                                     By  /s/ George F.  Sherwin, Jr.
                                     George F.  Sherwin, Jr., its Vice President



                                   OPTIVA:

                                     OPTIVIA CORPORATION



                                        By  /s/ David Giuliani
                                        David Giuliani, its President


                                       12
<PAGE>   13


STATE OF WASHINGTON   )
                      )ss.
COUNTY OF KING        )

        On this 26th day of November, 1997, before me, the undersigned, a Notary
Public in and for the State of Washington, personally appeared George F.
Sherwin, Jr., to me known to be the Vice President of THE QUADRANT CORPORATION,
the corporation that executed the foregoing instrument, and acknowledged the
said instrument to be the free and voluntary act and deed of said corporation,
for the uses and purposes therein mentioned, and on oath stated that he/she was
authorized to execute the said instrument on behalf of said corporation.

        WITNESS MY HAND AND OFFICIAL SEAL hereto affixed the day and year first
above written.

                                          /s/ Linda L.  Hamm
                                          ------------------------------------
                                          Name  Linda L.  Hamm
                                               -------------------------------
                                          NOTARY PUBLIC in and for the State of
                                          Washington, residing at Redmond, WA.
                                          My commission expires 4-25-2000    .


STATE OF WASHINGTON   )
                      )ss.
COUNTY OF KING        )

        On this 26th day of November, 1997, before me, the undersigned, a Notary
Public in and for the State of Washington, personally appeared David Giuliani,
to me known to be the President of OPTIVA CORPORATION, the corporation that
executed the foregoing instrument, and acknowledged the said instrument to be
the free and voluntary act and deed of said corporation, for the uses and
purposes therein mentioned, and on oath stated that he/she was authorized to
execute the said instrument on behalf of said corporation.

        WITNESS MY HAND AND OFFICIAL SEAL hereto affixed the day and year first
above written.

                                          /s/ Linda L.  Hamm
                                          ------------------------------------
                                          Name  Linda L.  Hamm
                                               -------------------------------
                                          NOTARY PUBLIC in and for the State of
                                          Washington, residing at Redmond, WA.
                                          My commission expires 4-25-2000    .


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