<PAGE>   1
                                                                    CONFIDENTIAL


                               THE EVANS COMPANY


                                                               September 6, 1995



                            STATEMENT OF ADJUSTMENTS



        Tenant Name:                Optiva Corporation

        and Address:                13226 SE 30th St B-1
                                    Bellevue WA 98005

        Lease Site Location:        Mercer Park

        Square Footage:             810

        Current Lease Term:         09/15/95 - 12/31/98

        Date of Lease:              September 6, 1995



                         STATEMENT OF TOTAL MONTHLY RENT


<TABLE>
<S>                                                                             <C>         
Minimum Monthly Rent                                                            $     648.00

Monthly Share of Estimated Adjustments:                                               142.00
      Taxes, insurance, common area maintenance, utilities and garbage.

TOTAL MONTHLY RENT BEGINNING OCTOBER 1, 1995                                    $     790.00
</TABLE>



<PAGE>   2


        THE EVANS COMPANY

                                 Lease Agreement
                                Table of Contents


<TABLE>
<CAPTION>
Section                           Title                           Page
-------                           -----                           ----
<S>                               <C>                             <C>

                                  Lease Summary                   3
1                                 Premises                        4
2                                 Term                            4
3                                 Rent                            5
4                                 Security Deposit                6
5                                 Property Taxes and Insurance    7
6                                 Personal Property Taxes         7
7                                 Insurance and Indemnity         8
8                                 Use, Signs, Liens               10
9                                 Utilities and Janitor Service   12
10                                Maintenance of Premises         12
11                                Common Areas                    13
12                                Alterations                     14
13                                Assignment and Subletting       15
14                                Access by Landlord              15
15                                Damage or Destruction           16
16                                Default or Re-Entry             16
17                                Late Charges                    17
18                                Costs and Attorney's Fees       17
19                                Non-Waiver of Breach            17
20                                Removal of Property             18
21                                Heirs and Successors            18
22                                Hold-Over                       18
23                                Subordination, Quiet Enjoyment  18
24                                Personal Property and Trade     19
                                  Fixtures
25                                Condemnation                    19
26                                Notices                         20
27                                Corporate Authority             20
28                                Miscellaneous                   20
29                                Hazardous and Toxic Waste       21
                                  Materials
30                                Special Articles                22

Exhibit
-------
A                                 Legal Description
B                                 Site Plan
C                                 Description of Landlord's and Tenants Work of Improvement
C-1                               Demising Plan of Premises
D                                 Corporate Resolution of Tenant
E                                 Guaranty of Lease
</TABLE>



                                       2

<PAGE>   3



                                  LEASE SUMMARY


<TABLE>
<S>                                           <C>    
                                 LEASE DATE:  September 6, 1995

                                   LANDLORD:  The Evans Company

                         ADDRESS OF LANDLORD: 1457 130th Ave NE
                                              Bellevue WA 98005

                                   TELEPHONE: 454-8211

                         TENANT'S TRADE NAME: Optiva Corporation

    ADDRESS OF TENANT (Address of Premises):  13226 SE 30th St B-1
                                              Bellevue WA 98005

                      TELEPHONE AT PREMISES:  957-0970

               BUSINESS HOME OFFICE ADDRESS:  13222 SE 30th A-1
                                              Bellevue WA 98005

             BUSINESS HOME OFFICE TELEPHONE:  957-0970

                    OWNER RESIDENCE ADDRESS:

                  OWNER RESIDENCE TELEPHONE:

      PREFERRED MAILING ADDRESS FOR NOTICES:      PREMISES
                                              xx  BUSINESS HOME OFFICE
                                                  OWNER RESIDENCE

                            LEASED PREMISES:  BUILDING      B
                                              SPACE(S)      1

  SQUARE FEET OF PREMISES APPROXIMATELY       810

                            LEASE TERM:       39.5     MONTHS

                     LEASE COMMENCEMENT DATE: September 15, 1995

                      RENT COMMENCEMENT DATE: September 15, 1995

                      LEASE TERMINATION DATE: December 31, 1998

                       MINIMUM MONTHLY RENT:  Six Hundred Forty-eight and NO/100 Dollars
                                              ($648.000)

                PER MONTH AS INCREASED BY THE TERMS OF THE LEASE.

                           SECURITY DEPOSIT:  Nine Hundred and NO/100 Dollars ($900.00)

                             PERMITTED USES:  Office

                                  GUARANTOR:  David Giuliani

                        ADDRESS OF GUARANTOR: 13226 SE 30th St B-1
                         (Business Address)   Bellevue WA 98005

                                TELEPHONE NO: 957-0970
</TABLE>



THE EVANS COMPANY                                       Landlord's Initials_____
                                                          Tenant's Initials_____


                                       3
<PAGE>   4

                                 LEASE AGREEMENT



     THIS LEASE, dated for reference purposes only, September 6, 1995 , is made
by and between The Evans Company (hereinafter "Landlord") and Optiva Corporation
(hereinafter "Tenant"). For and in consideration of the rental and of the
covenants and agreements hereinafter set forth to be kept and performed by the
Tenant, Landlord hereby leases to Tenant and Tenant hereby leases from Landlord
the Premises herein described for the term, at the rental and subject to and
upon all of the terms, covenants and agreements hereinafter set forth.

1.      PREMISES

        1.1 PREMISES. Landlord hereby leases to Tenant and Tenant hereby leases
from Landlord that certain space (herein called "Premises") containing
approximately 810 square feet of floor area, the approximate location of which
is shown crosshatched on Exhibit B attached hereto. The Premises are located in
Mercer Park, the legal description of which is set forth on Exhibit A attached
hereto, which is in the City of Bellevue, County of King, State of Washington.
The address of the Premises is as follows: 13226 SE 30th St. B-1, Bellevue WA
98005. This Lease is subject to the terms, covenants and conditions herein set
forth and the Tenant covenants as a material part of the consideration for this
Lease to keep and perform each and all of said terms, covenants and conditions
by it to be kept and performed.

        1.2 WORK OF IMPROVEMENT. The obligations of Landlord and Tenant to
perform the work and supply material and labor to prepare the Premises for
occupancy are set forth in detail in Exhibits C and C-1. Landlord and Tenant
shall expend all funds and do all acts required in Exhibit C and C-1 and shall
have the work performed promptly and diligently in a first-class workmanlike
manner. By taking possession of the premises, Tenant acknowledges that it has
examined the Premises and accepts the Premises in their condition at the time of
taking possession thereof.

2.      TERM

        2.1 TERM. The Term of this Lease shall be for 39.5 (thirty nine and a
half) months commencing September 15, 1995 and ending on December 31, 1998
unless sooner terminated pursuant to this Lease. The rent commencement date
shall be September 15, 1995 ("Rent Commencement Date").

        2.2 COMMENCEMENT. Tenant agrees that in the event of the inability of
Landlord for any reason to deliver possession of the Premises to Tenant on the
commencement date set forth in Section 2.1, Landlord shall not be liable for any
damage thereby nor shall such inability affect the validity of this Lease or the
obligations of Tenant hereunder, but in such case Tenant shall not be obligated
to pay rent or other monetary sums until possession of the Premises is tendered
to Tenant; provided that if the delay in delivery of possession exceeds thirty
(30) days, then the expiration date of the term of the Lease shall be extended



                                       4

<PAGE>   5

by the period of time computed from the scheduled commencement date to the date
possession is tendered. In the event Landlord shall not have delivered
possession of the Premises within four (4) months from the scheduled
commencement date, then Tenant at its option to be exercised within thirty (30)
days after the end of said four (4) month period may terminate this Lease and
upon Landlord's return of any moneys previously deposited by Tenant the parties
shall have no further rights or liabilities toward each other. If Tenant
occupies the Premises prior to said commencement date, such occupancy shall be
subject to all provisions hereof, such occupancy shall not advance the
termination date and Tenant shall pay rent for such period at the initial
monthly rates as set forth below.

        2.3 DELIVERY OF POSSESSION. Tenant shall be deemed to have taken
possession of the Premises when any of the following occur: (a) Landlord
delivers possession of the Premises to Tenant and a Certificate of Occupancy is
granted by the proper governmental agency, (b) upon a letter from Landlord that
the Premises are ready for occupancy, or (c) upon occupancy by the Tenant.

3.      RENT

        3.1 MINIMUM MONTHLY RENT. Tenant shall pay to Landlord as Minimum
Monthly Rent for the Premises the sum of Six Hundred Forty-eight and NO/100
Dollars ($648.00) per month, which sum shall be paid in advance on the first day
of each calendar month beginning with the Rent Commencement Date and thereafter
throughout the term of the Lease. All rent to be paid by Tenant to Landlord
shall be paid in lawful money of the United States of America and shall be
without deduction or offset, prior notice or demand, and at such place or places
as may be designated from time to time by Landlord. If the Rent Commencement
date is not the first day of a month, or if the lease termination date is not
the last day of a month, a pro rated monthly installment shall be paid at the
then current rate for me fractional month during which the Lease commences
and/or terminates. Concurrently with Tenant's execution of this Lease, Tenant
shall pay to Landlord the sum Three Hundred Ninety-five and NO/100 Dollars
($395.00) as Minimum Monthly Rent and Adjustments for September 1995.

        The Minimum Monthly Rent shall be increased or decreased by the
percentage of change, if any, in the Consumer Price Index - All Urban Consumers,
All Items (1982 - 84 = 100) equals Base ("CPI"), as published by the United
States Department of Labor's Bureau of Labor Statistics. The base period, for
purposes of such adjustment, shall be the CPI for the fourth calendar month
immediately preceding the first Lease Year (the "Base CPI"). The Minimum Monthly
Rent shall be adjusted for each Lease Year after the first Lease Year on the
basis of the percentage change in the CPI for the fourth calendar month
immediately preceding the Lease Year subject to adjustment compared to the Base
CPI. In no event, however, shall the rent payable in any Lease Year be reduced
below the Minimum Monthly Rent. Should the CPI be discontinued, the parties
shall select another similar index which reflects consumer prices and if the
parties cannot agree on another index it shall be selected by the Superior Court
of the County in which the premises are located.



                                       5

<PAGE>   6

        (By way of illustration only, if the Base CPI is 190 and the CPI figure
for the fourth month before the second Lease Year is 195, then the Minimum
Monthly Rent for the second lease year shall be increased by 2.63%.)

        3.2 ADJUSTMENTS. In addition to the Minimum Monthly Rent provided in
Section 3.1 above, Tenant shall pay to Landlord in monthly installments the
Tenant's portion of those items, herein called "Adjustments", delineated in
Sections 5, 9, 10 and 11. Upon commencement of the Term Landlord shall submit to
Tenant a statement of the anticipated monthly Adjustments for the period between
such commencement and the following January and Tenant shall pay same and all
subsequent monthly payments concurrently with the payment of Minimum Monthly
Rent. Tenant shall continue to make said monthly payments until notified by
Landlord of a change thereof. By March 1 of each year Landlord shall endeavor to
give Tenant a statement showing the total Adjustments for the Mercer Park for
the prior calendar year and Tenant's allocable share thereof, prorated from the
commencement of rental. Tenant's pro rata share, where applicable, shall be
determined in accordance with the total floor area of the Premises as it relates
to the total gross leasable floor area of the building or buildings of which the
Premises are a part. In the event the total of the monthly payments which Tenant
has made for the prior calendar year are less than Tenant's actual share of such
Adjustments then Tenant shall pay the difference in a lump sum within ten days
after receipt of such statement from Landlord and shall concurrently pay the
difference on monthly payments made in the then calendar year and the amount of
monthly payments which are then calculated as monthly Adjustments based on the
prior year's experience. Any overpayment by Tenant shall be credited towards the
monthly Adjustments next coming due. The actual Adjustments for the prior year
shall be used for purposes of calculating the anticipated monthly Adjustments
for the then current year, with actual determination of such Adjustments after
each calendar year as above provided. Even though the term has expired and
Tenant has vacated the Premises, when the final determination is made of
Tenant's share of said Adjustments for the year in which this Lease terminated,
Tenant shall immediately pay any increase due over the estimated Adjustments
previously paid and, conversely, any overpayment made shall be immediately
rebated by Landlord to Tenant.

4.      SECURITY DEPOSIT

        Concurrently with Tenant's execution of this Lease, Tenant shall deposit
with Landlord the sum of Nine Hundred and NO/100 Dollars ($900.00). Said sum
shall be held by Landlord as a Security Deposit for the faithful performance by
Tenant of all of the terms, covenants, and conditions of this Lease to be kept
and performed by Tenant during the term hereof. If Tenant defaults with respect
to any provisions of this Lease, including but not limited to the provisions
relating to the payment of rent and any of the monetary sums due herewith,
Landlord may (but shall not be required to) use, apply or retain all or any part
of this Security Deposit for the payment of any other amount which Landlord may
spend or become obligated to spend by reason of Tenant's default or to
compensate Landlord for any other loss or damage which Landlord may suffer by
reason of Tenant's 



                                       6

<PAGE>   7

default. If any portion of said Deposit is so used or applied, Tenant shall,
within ten (10) days after written demand therefor, deposit cash with Landlord
in an amount sufficient to restore the Security Deposit to its original amount;
Tenant's failure to do so shall be material breach of this Lease. Landlord shall
not be required to keep this Security Deposit separate from its general funds,
and Tenant shall not be entitled to interest on such Deposit. If Tenant shall
fully and faithfully perform every provision of this Lease to be performed by
it, the Security Deposit or any balance thereof shall be returned to Tenant (or,
at Landlord's option, to the last assignee of Tenant's interest hereunder) at
the expiration of the Lease term and after Tenant has vacated the Premises. In
the event of termination of Landlord's interest in this Lease, Landlord shall
transfer said Deposit to Landlord's successor in interest, whereupon Tenant
agrees to release Landlord from all liability for the return of such Deposit or
the accounting therefore.

5.      ADJUSTMENTS FOR REAL PROPERTY TAXES AND INSURANCE

        In addition to the Minimum Monthly Rent provided in Section 3.1 above,
and commencing as of the commencement of the term of the Lease, Tenant shall pay
to Landlord in monthly installments, the Tenant's portion of the following items
herein called "Adjustments":

        All insurance premiums paid on policies, maintained by Landlord with
respect to the Premises, including land, building and improvements including
without limitation, all premiums for fire, extended coverage, liability with
respect to the Premises and all real estate taxes imposed on the Premises or
arising in respect to the occupancy, use or possession of the Premises. Real
property taxes shall include, without limitation, all assessments whether
general, special, ordinary, extraordinary, unforeseen or foreseen, of any kind
or nature levied, imposed or to become a lien upon or against the Premises and
any building, structure, fixture, improvement, personal property or inventory
now or hereafter located thereon, assessment or improvement bonds for water,
sewer, road and other public purposes, license, permit and inspection fees and
taxes, commercial rental tax and any other public charge, levy, penalty or
assessment against any interest in the Premises or the real property of which
the Premises are a part, or against Landlord's right to rent or other income
therefrom (other than income taxes). All of the foregoing expenses shall be
apportioned in accordance with the Tenant's "pro rata share" which shall be
determined in accordance with the total floor area of the Premises as it relates
to the total gross leasable floor area of the building or buildings which the
Premises are a part; provided, however, that if any tenants in said building or
buildings pay taxes directly to any taxing authority or carry their own
insurance, as may be provided in their leases, their square footage shall not be
deemed a part of the floor area for purposes of prorating such expenses.

6.      PERSONAL PROPERTY TAXES

         Tenant shall pay, before delinquency, all taxes, assessments, license
fees and public charges levied, assessed or imposed upon or measured by the
value of its business 



                                       7

<PAGE>   8

operation, including but not limited to the furniture, fixtures, leasehold
improvements, equipment and other property of Tenant at any time situated on or
installed in the Premises by Tenant. If at any time during the term of this
Lease any of the foregoing are assessed as part of the real property of which
the Premises are a part, Tenant shall pay to Landlord upon demand the amount of
such additional taxes as may be levied against said real property by reason
thereof. For the purpose of determining said amount, figures supplied by the
County Assessor as to the amount so assessed shall be conclusive.

7.      INSURANCE AND INDEMNITY

        7.1 INDEMNIFICATION. It is understood and agreed that Landlord shall not
be liable for injury to any person, or for the loss of or damage to any property
(including property of Tenant) occurring in or about the Premises from any cause
whatsoever except for Landlord's negligence or willful misconduct. Tenant hereby
indemnifies and holds Landlord harmless from and against and agrees to defend
Landlord against any and all claims, charges, liabilities, obligations,
penalties, damages, costs and expenses (including attorney's fees) arising,
claimed, charged or incurred against or by Landlord from any matter or thing
arising from Tenant's use of the Premises, the conduct of its business or from
any activity, work or other things done, permitted or suffered by the Tenant in
or about the Premises, and Tenant shall further indemnify and hold harmless
Landlord from and against any and all claims arising from any breach or default
in the performance of any obligation on Tenant's part to be performed under the
terms of this Lease, or arising from any act or negligence of the Tenant, or any
officer, agent, employee, guest, or invitee of Tenant, and from all costs,
attorney's fees and liabilities incurred in or about the defense of any such
claim or any action or proceeding brought thereon and in case any action or
proceeding be brought against Landlord by reason of such claim. Tenant, upon
notice from Landlord, shall defend the same at Tenant's expense by counsel
reasonably satisfactory to Landlord. Tenant as a material part of the
consideration to Landlord hereby assumes all risk of damage to property or
injury to persons in, upon or about the Premises, from any cause other than
Landlord's negligence, or willful misconduct, and Tenant hereby waives all
claims in respect thereof against Landlord. The indemnification provided for in
this Section with respect to any acts or omissions during the term of this Lease
shall survive any termination or expiration of this Lease. Landlord and its
agents shall not be liable for any toss or damage to persons or property
resulting from fire, explosion, falling plaster, steam, gas, electricity, water
or rain which may leak from any part of the Premises or from pipes, appliances
or plumbing works therein or from the roof, street or subsurface or from any
other place resulting from dampness or any other cause whatsoever, unless caused
by or due to the negligence of Landlord, its agents, servants or employees.
Landlord and its agents shall not be liable for interference with the light, on
the Premises. Tenant shall give prompt notice to Landlord in case of casualty or
accidents on the Premises.

        7.2 INSURANCE. During the entire Lease Term the Tenant shall, at its own
expense, maintain adequate liability insurance with a reputable insurance
company or companies 



                                       8

<PAGE>   9

with minimum amounts of $1,000,000.00 Combined Single Limits (including bodily
injury and property damage) to indemnify both Landlord and Tenant against any
such claims, demands, tosses, damages, liabilities and expenses. Landlord shall
be named as one of the insureds and shall be furnished with a copy of such
policy or policies of insurance, which shall bear an endorsement that the same
shall not be canceled except upon not less than twenty (20) days prior written
notice to Landlord. Tenant shall also at its own expense maintain, during the
Lease Term, insurance covering its furniture, fixtures, equipment and inventory
in an amount equal to the full insurable value thereof, against fire and risks
covered by standard extended coverage endorsement and insurance covering all
plate glass and outer glass on the Premises. Tenant shall provide Landlord with
copies of the policies of insurance or certificates thereof. If Tenant fails to
maintain such insurance, Landlord may maintain the same on behalf of Tenant. Any
premiums paid by Landlord shall be deemed additional rent and shall be due on
the payment date of the next installment of Minimum Monthly Rental hereunder.

        7.3 INCREASE IN INSURANCE PREMIUM. Tenant shall not keep, use, sell or
offer for sale in or upon the Premises any article which may be prohibited by
the standard form of fire insurance policy. Tenant shall pay any increase in
premiums for casualty and fire (including extended coverage) insurance that may
be charged during the Term of this Lease on the amount of such insurance which
may be carried by Landlord on the Premises or the building of which they are a
part, resulting from Tenant's occupancy or from the type of merchandise which
Tenant stores or sells on the Premises, whether or not Landlord has consented
thereto. In such event, Tenant shall also pay any additional premium on the
insurance policy that Landlord may carry for its protection against rent loss
through fire or casualty. In determining whether increased premiums are the
result of Tenant's use of the Premises, a schedule, issued by the organization
setting the insurance rate on the Premises, showing the various components of
such rate, shall be conclusive evidence of the several items and charges which
make up the casualty and fire insurance rate on the Premises. Landlord shall
deliver bills for such additional premiums to Tenant at such times as Landlord
may elect, and Tenant shall immediately reimburse Landlord therefor.

        7.4 WAIVER OF SUBROGATION. Landlord and Tenant hereby mutually release
each other from liability and waive all right of recovery against each other for
any loss in or about the Premises, from perils insured against under their
respective fire insurance contracts, including any extended coverage
endorsements thereof, whether due to negligence or any other cause; provided
that this Section shall be inapplicable if it would have the effect, but only to
the extent it would have the effect, of invalidating any insurance coverage of
Landlord or Tenant.

        7.5 COMPANIES. Insurance required hereunder shall be issued by companies
rated AAA or better in "Bests" Insurance Guide.

        7.6 CERTIFICATE OF INSURANCE. A certificate issued by the insurance
carrier for each policy of insurance required to be maintained by Tenant under
the provisions of this Lease shall be delivered to Landlord on or before the
commencement date of the Lease Term hereof and thereafter, as respects policy
renewals, within thirty (30) days prior to the 



                                       9

<PAGE>   10

expiration of the term of each such policy. Each of said certificates of
insurance and each such policy of insurance required to be maintained by Tenant
hereunder shall expressly evidence insurance coverage as required by this Lease.
All such policies shall be written as primary policies not contributing with and
not in excess of coverage which Landlord may carry.

8.      USE

        8.1 USE. The Premises shall be used and occupied by Tenant for only the
following purposes and for no other purposes whatsoever without obtaining the
prior written consent of Landlord: Office, Research, assembly and other uses
consistent with those currently occurring in Bldg.

        8.2 SUITABILITY. If the Premises are completed as of the date of
execution hereof, then Tenant, by the date of execution of this Lease, shall be
deemed to have accepted the Premises in the condition existing as of the dale of
execution and in any event this Lease shall be subject to all applicable zoning
ordinances and to any municipal, county and state laws and regulations governing
and regulating the use of the Premises. Tenant acknowledges that neither
Landlord nor Landlord's agent has made any representation or warranty as to the
suitability of the Premises for the conduct of Tenant's business.

        8.3 USES PROHIBITED. Tenant shall not do or permit anything to be done
in or about the Premises which will increase the existing rate of insurance upon
the Premises (unless Tenant shall pay any increased premium as a result of such
use or acts) or cause the cancellation of any insurance policy covering said
Premises or any building of which the Premises may be a part, nor shall Tenant
sell or permit to be kept, used or sold in or about said Premises any articles
which may be prohibited by a standard form policy of fire insurance.

        Tenant shall not do or permit anything to be done in or about the
Premises which will obstruct or interfere with the rights of other tenants or
occupants of any building of which the Premises may be a part or injure or annoy
them or use or allow the Premises to be used for any unlawful, nor shall Tenant
cause, maintain or permit any nuisance in, on or about the Premises. Tenant
shall not commit or suffer to be committed any waste in or upon or about the
Premises.

        Tenant shall not dispose of nor otherwise allow the release of any
hazardous waste or substance in, on or under the Premises, any improvements
placed thereon or any adjacent property. Tenant represents and warrants to
Landlord that Tenant's intended use of the Premises does not involve the use,
production, disposal or bringing on the Premises of any hazardous waste or
substance of types other than, or in quantities in excess of, those normally
incident to the use of the Premises for general office use. For purposes of this
Lease the term "hazardous waste or substance" shall mean any substance, waste or
material defined or designated as hazardous, toxic or dangerous (or any similar
term) by any federal, state or local statute regulation, rule or ordinance now
or hereafter in effect.

        Tenant shall not use the Premises or permit anything to be done in or
about the Premises which will in any way conflict with any law, statute, zoning
restriction, ordinance 



                                       10

<PAGE>   11

or governmental rule or regulation or requirements or duly constituted public
authorities now in force or which may hereafter be enacted or promulgated.
Tenant shall at its sole cost and expense promptly comply with all laws,
statutes, ordinances and governmental rules, regulations or requirements now in
force or which may hereafter be in force and with the requirements of any board
of fire underwriters or other similar body now or hereafter constituted relating
to or affecting the condition, use or occupancy of the Premises. The judgment of
any court of competent jurisdiction, whether Landlord be a party thereto or not,
that Tenant has violated any law, statute, ordinance or governmental rule,
regulation or requirement, shall be conclusive of that fact as between Landlord
and Tenant.

8.4     SIGNS.

        (a) GENERAL. Tenant shall not place or suffer to be placed on the
exterior walls of the Premises or upon the roof or any exterior door or wall or
on the exterior or interior of any window thereof any sign, awning, canopy,
marquee, advertising matter, decoration, letter or other thing of any kind
(exclusive of signs, if any, which may be provided for in the original
construction or improvement plans and specifications approved by the Landlord or
Tenant herein, and which conform to the Landlord's sign criteria as specified in
Exhibit F attached hereto if applicable) without the prior written consent of
Landlord. Landlord hereby reserves the exclusive right to the use for any
purpose whatsoever of the roof and exterior of the walls of the Premises or the
Building of which the Premises are a part.

        (b) TENANT'S INTERIOR SIGNS. Except as otherwise herein provided, Tenant
shall have the right, at its sole cost and expense, to erect and maintain within
the interior of the Premises all signs and advertising matter customary or
appropriate in the conduct of Tenant's business; provided, however, that Tenant
shall upon demand of the Landlord immediately remove any sign, advertisement,
decoration, lettering or notice which Tenant has placed or permitted to be
placed in, upon or about the Premises and which Landlord reasonably deems
objectionable or offensive, and if Tenant fails or refuses do to so, the
Landlord may enter upon the Premises and remove the same at Tenant's cost and
expense.

        8.5 LIENS. Tenant shall keep the Premises and any building of which the
Premises are a part free from any liens arising out of work performed, materials
furnished or obligations incurred by Tenant and shall indemnify, hold harmless
and defend Landlord from any liens and encumbrances arising out of any work
performed or material furnished by or at the direction of Tenant. In the event
that Tenant shall not, within twenty (20) days following the imposition of any
such lien, cause such lien to be released of record by payment or posting of a
proper bond not to be less than 120% of the lien claim, Landlord shall have, in
addition to all other remedies provided herein and by law, the right, but not
the obligation, to cause the same to be released by such means as it shall deem
proper, including payment of the claim giving rise to such lien. All such sums
paid by Landlord and all expenses incurred by it in connection therewith
including attorney's fees and costs shall be payable to Landlord by Tenant on
demand. Landlord shall have the right at all times to post and keep posted on
the Premises any notices permitted or required by law, or 



                                       11

<PAGE>   12

which Landlord shall deem proper, for the protection of Landlord and the
Premises, and any other party having an interest therein, from mechanics' and
material men liens, and Tenant shall give to Landlord at least ten (10) business
days prior written notice of the expected dale of commencement of any work
relating to alterations or additions to the Premises.

9.      UTILITIES AND JANITOR SERVICE

        Tenant shall be liable for and shall pay throughout the term of this
Lease all charges for utilities, including but not limited to electricity, heat,
oil, gas and water consumed upon the leased Premises and telephone, sewage,
drainage and garbage disposal services, if any, including any charges imposed
for such services by the Municipality of Metropolitan Seattle (METRO); and shall
provide its own janitor services and replacement of light bulbs and tubes and
all washroom and toilet supplies. If any such services are not separately
metered to Tenant, Tenant shall pay its pro rata share as specified in Section
3.2 above.

10.     MAINTENANCE OF PREMISES

        10.1 MAINTENANCE AND REPAIR BY TENANT. Tenant shall at all times
throughout the Lease Term at its sole cost and expense, keep the Premises
(including exterior doors and entrances, all windows and mouldings and trim of
all doors and windows) and all partitions, door surfaces, fixtures, equipment
and appurtenances thereof (including lighting, heating and plumbing fixtures and
any air conditioning system) in good order, condition and repair, damage by
unavoidable casualty excepted (but not excluding damage from burglary or
attempted burglary of the Premises). When there is an air conditioning system,
Landlord will contract for service checks and filter changes and Tenant agrees
to pay for such service calls and filter changes on the units serving Tenant's
Premises, all as set forth in Section 3.2 above. Without limiting the
generalities thereof, Tenant shall keep the glass of all windows, doors, and
showcases clean and presentable; replace immediately all broken glass in the
Premises; at reasonable intervals paint or refinish the inferior of the
Premises; make any necessary repairs to, or replacements of, all door closure
apparatuses and mechanisms; keep all plumbing clean and in good state of repair
including pipes, drains, toilets, basins and those portions of the heating
system within the walls of the Premises; and keep all utilities within the
Premises in a good state of repair upon the failure of Tenant to do so.

        10.2 FAILURE TO MAINTAIN. If Tenant fails to keep and preserve the
Premises as set forth in Section 10.1 above, Landlord may at its option, put or
cause the same to be put in the condition and state of repair agreed upon, and
in such case, upon receipt of written statements from Landlord, Tenant shall
promptly pay the entire cost thereof as additional rent. Landlord shall have the
right, without liability, to enter the Premises for the purpose of making such
repairs.

        10.3 REPAIRS BY LANDLORD. Landlord shall keep the roof, exterior walls,
foundations and buildings structure of the Premises in a good state of repair,
and shall accomplish such repairs as may be needed promptly after receipt of
written notice from Tenant. Should such repairs be required by reason of
Tenant's negligent acts, Tenant shall 



                                       12

<PAGE>   13

promptly pay Landlord for the cost thereof as additional rent. Tenant shall
immediately inform Landlord of any necessary repairs and Tenant shall make none
of such repairs without Landlord's prior written consent. Landlord shall not be
liable for any failure to make any such repairs or to perform any maintenance
required of Landlord hereunder unless such failure shall persist for an
unreasonable time after written notice of the need of such repair is given to
Landlord by Tenant. Except as otherwise specifically provided herein, there
shall be no abatement of rent and no liability of Landlord by reason of any
injury to or interference with Tenants business arising from the making of any
repairs, alterations or improvements in or to any portion of the Premises or
building of which the Premises is a part or in or to fixtures, appurtenances and
equipment herein.

        10.4 SURRENDER OF PREMISES. At the expiration or sooner termination of
this Lease, Tenant shall return the Premises to Landlord in the same condition
in which received (or, if altered by Landlord or by Tenant with the Landlord's
consent, then the Premises shall be returned in such altered condition),
reasonable wear and tear excepted. Tenant shall remove all trade fixtures,
appliances and equipment which do not become a part of the Premises and
alterations which Landlord designates to be removed, and shall restore the
Premises to the condition they were in prior to the installation of said items.
Tenant's obligation to perform this covenant shall survive the expiration or
termination of this Lease.

        10.5 TAKING POSSESSION. By taking possession, Tenant shall be deemed to
have accepted the Premises as being in good and sanitary order, condition and
repair.

11.     COMMON AREAS

        11.1 CONTROL OF COMMON AREA BY LANDLORD. Landlord shall at all times
have the exclusive control and management of the Common Areas which shall
include but not be limited to all automobile parking areas, access roads,
driveways, entrances, retaining walls and exits thereto, the truck way or ways,
loading docks, package pick-up stations, washrooms, pedestrian malls, courts,
sidewalks and ramps, landscaped areas, exterior stairways, and other areas,
improvements, facilities and special services provided by Landlord for the
general use, in common, of tenants of the Mercer Park, and their officers,
agents, employees and invitees. With respect to the Common Areas and facilities,
Landlord shall have the right from lime to lime to employ personnel; to
establish, modify and enforce reasonable rules and regulations; to construct,
maintain and operate lighting facilities; to police the Common Areas and
facilities; from time to time to change the area, level, location and
arrangement of parking areas and other facilities herein above referred to; to
restrict parking by Tenant, its officers, agents and employees to employee
parking areas; to close all or any portion of the Common Areas and facilities to
such extent as may, in the opinion of Landlord's counsel be legally sufficient
to prevent a dedication thereof or the accrual of any person or the public
therein; to close temporarily all or any portion of the parking areas or
facilities; to discourage non-customer parking; and to do and perform such other
acts in and to the Common Areas and facilities as, in the use of good business
judgment, Landlord shall determine to be advisable with a view to the
improvement of the 



                                       13

<PAGE>   14

convenience and use thereof by Tenants of the Mercer Park, their employees,
invitees and customers.

        11.2 LICENSE. All Common Areas and facilities excluding Tenant's
physical space which Tenant may be permitted to use and occupy, are to be used
and occupied under a revocable license. If the amount of such areas or
facilities be diminished, such diminution shall not be deemed constructive or
actual eviction, Landlord shall not be subject to any liability, nor shall
Tenant be entitled to any compensation or diminution or abatement of rent.
Provided however, Landlord shall provide parking to reasonably accommodate the
operation of Tenant's business.

        11.3 MAINTENANCE CHARGE. Tenant shall pay to Landlord, additional rent,
in the manner provided in Section 3.2 a monthly maintenance charge to defray the
operating cost of the Common Areas and facilities. The amount of the monthly
Maintenance Charge shall be equal to 1/12 of Tenants estimated pro rate share of
the operating costs for the calendar year, which share shall be determined by
multiplying such costs by a fraction, the numerator of which is the total floor
area of the leased Premises and the denominator of which is the total gross
leasable floor area of Mercer Park on the first day of such calendar year. For
purposes of this paragraph, the term "operating cost of the Common Areas and
facilities" means the total cost and expense incurred in operating, accounting,
maintaining, administering and cleaning the Common Areas and facilities,
actually used or available for use by Tenant and the employees, agents, secants,
customers and invitees of Tenant, specifically including, without limitation,
gardening and landscaping, the cost of public liability and property damage
insurance, repairs, asphalt patching, line painting, minor roof repairs,
lighting, sanitary control, removal of snow, trash rubbish, garbage and other
refuse, machinery and equipment used in such maintenance, and the cost of
personnel to implement such services, including the policing of and traffic
control on the Common Areas and facilities. Management fees shall be limited to
the lesser of fair market value or 5%.

12.     ALTERATIONS

        12.1 ACCEPTANCE OF LEASE PREMISES. Upon acceptance of the Premises by
Tenant, Tenant shall acknowledge to Landlord that Tenant has inspected the
leased Premises and accepts them in their present condition or else shall notify
Landlord of any deficiencies then apparent.

        12.2 ALTERATIONS BY TENANT. Tenant shall not make any alterations,
additions or improvements in or to the leased Premises without the prior written
consent of Landlord, which consent may be reasonably subject to such conditions
as Landlord may deem appropriate. Any such alterations, additions or
improvements consented to by Landlord shall be made at Tenant's sole expense.
Tenant shall secure any and all governmental permits required in connection with
any such work, and shall hold Landlord harmless from any and ail liability
(including attorney's fees) and any and all liens resulting therefrom. All
alterations, additions and improvements (and expressly including all light
fixtures and floor coverings), except trade fixtures and appliances and
equipment which do not become 



                                       14

<PAGE>   15

a part of the leased Premises, excepting cabinets and general equipment
installed by Tenant may be removed provided tenant repairs all damage caused by
removal, shall immediately become the property of Landlord without any
obligation to pay therefor, and shall not be removed by Tenant. Upon the
expiration or sooner termination of the Term hereof, at Landlord's option Tenant
shall at Tenant's sole cost and expense, forthwith and with all due diligence,
remove any alterations, additions, or improvements made by Tenant, which
Landlord designates to be removed, and Tenant shall, forthwith and with all due
diligence, at its sole cost and expense, repair any damage to the Premises
caused by such removal.

13.     ASSIGNMENT AND SUBLETTING

               Tenant shall not assign, transfer, mortgage, pledge, hypothecate
or encumber this Lease or any interest therein, nor sublet the whole or any part
of the Premises, nor shall this Lease or any interest hereunder be assignable or
transferable by operation of law or by any process or proceeding of any court,
or otherwise, without the prior written consent of Landlord which consent may be
reasonably subject to such conditions as Landlord may deem appropriate and which
consent may not be unreasonably withheld. Without in any way limiting Landlord's
right to refuse to give such consent for any other reason or reasons, Landlord
reserves the right to refuse to give such consent unless Tenant remains fully
liable during the unexpired Lease Term hereof and Landlord further reserves the
right to refuse to give such consent if in Landlord's reasonable business
judgment the quality of merchandising experience or the financial worth of the
proposed new Tenant is less than that of the Tenant executing this Lease or of
Tenant and Tenant's Guarantor as the case may be. Tenant agrees to reimburse
Landlord for Landlord's reasonable attorneys' fees incurred in conjunction with
the processing and documentation of any such requested transfer, assignment,
subletting, licensing or concession agreement, change of fee ownership or
hypothecation of this Lease or Tenant's interest in and to the Premises.

14.     ACCESS BY LANDLORD

        14.1 RIGHT OF ENTRY. Landlord or Landlord's employees, agents and/or
contractors shall have the right to enter the Premises at any time to examine
the same, and to show them to prospective purchasers or Tenants of the Building,
and to make such repairs, alterations, improvements or additions as Landlord may
deem reasonably necessary or desirable. If Tenant is not personally present to
permit entry and an entry is necessary, Landlord may in case of emergency
forcibly enter the same, without rendering Landlord liable therefor. Nothing
contained herein shall be construed to impose upon Landlord any duty of repair
of the Premises or Building of which the Premises are a part except as otherwise
specifically provided for herein.

        14.2 EXCAVATION. If an excavation is made upon property adjacent to the
Premises, Tenant shall afford to the person causing or authorized to cause such
excavation, license to enter upon the Premises for the purpose of doing such
work as Landlord shall deem reasonably necessary to preserve the wall of the
building of which the Premises is a part from injury or damage and to support
the same by proper foundations, without any claim for damages or indemnification
against Landlord or diminution or abatement of rent.



                                       15

<PAGE>   16

15.     DAMAGE OR DESTRUCTION

        In the event the Premises are damaged to such an extent as to render the
same untenantable in whole or in a substantial part thereof, or are destroyed,
it shall be optional with the Landlord to repair or rebuild the same; and after
the happening of any such contingency, the Tenant shall give Landlord or
Landlord's agent immediate written notice thereof. Landlord shall have not more
than ninety (90) days after date of such notification to notify the Tenant in
writing of Landlord's intention to repair or rebuild said Premises, or the part
so damaged as aforesaid, and if Landlord elects to repair or rebuild said
Premises, Landlord shall prosecute the work of such repairing or rebuilding
without unnecessary delay, and during such period the rent of said Premises
shall be abated in the same ratio that that portion of the Premises rendered for
the time being unfit for occupancy shall bear to the whole of the leased
Premises. If the Landlord shall fail to give the notice aforesaid, Tenant shall
have the right to declare his Lease terminated by written notice upon the
Landlord or Landlord's agent. In the event the building in which the Premises
hereby leased are located shall be damaged (even though the Premises hereby
shall not be damaged thereby) to such an extent that in the opinion of Landlord
it shall not be practical to repair or rebuild, or is destroyed, then it shall
be optional with Landlord to terminate this Lease by written notice served on
Tenant within ninety (90) days after such damage or destruction.

16.     DEFAULT AND RE-ENTRY

               If any rents reserved herein or any part thereof shall be and
remain unpaid (10) days after the date they shall become due, or if Tenant shall
violate or default in any of the covenants or agreements herein contained, then
the Landlord may elect to:

        (a) terminate this Lease, in which event Tenant shall immediately pay to
Landlord all rent and other sums accrued to date plus the then present value of
the total rent and other sums reserved or due under the Lease for the balance of
the lease term. Tenant shall receive a credit against the amount due pursuant to
this subparagraph(s) equal to the reasonable rental value (which Tenant proves
by a preponderance of the evidence) of the Premises for the balance of the lease
term;

        (b) without terminating this Lease relet all or any part of the Premises
for the account of Tenant upon such terms and conditions as Landlord may deem
advisable, in which event the rents received on such reletting shall be applied
first to the expenses of reletting and collection (including without limitation,
all necessary renovation, repair and alteration of the Premises, reasonable
attorney fees, real estate commissions and rental or other concessions granted
to a new tenant) and thereafter to payment of all sums due or become due
Landlord hereunder, and if a sufficient amount is not realized to pay such sums
and other charges Tenant shall pay monthly to Landlord any deficiency and
Landlord may bring, at any time, an action for the entire amount of the
deficiency which will accrue during the balance of the lease term; or

        (c) pursue any other right or remedy Landlord may have under the laws of
the State of Washington.



                                       16

<PAGE>   17

        No action of Landlord shall terminate this Lease unless Landlord
notifies Tenant in writing that Landlord elects to terminate this Lease.
Landlord shall in no way be responsible or liable for any failure to relet the
property or any part thereof, or for any failure to collect any rent due upon
reletting. No reentry by Landlord shall excuse or relieve Tenant of its
liability and obligations under this lease and such liability and obligations
shall survive any such action by Landlord. Any sums received by Landlord upon
reletting of the property in excess of the rent and other sums due by Tenant
hereunder shall be the sole property of Landlord and Landlord shall not be
required to pay over any such sum to Tenant. Tenant assumes full responsibility
to mitigate damages resulting from Tenant's breach of abandonment by obtaining a
subtenant or assignee reasonably acceptable to Landlord. Landlord shall have no
responsibility to mitigate damages resulting from Tenant's breach or abandonment
other than to not unreasonably withhold consent to Tenant's proposed subleases
and assignments. Tenant waives any defense or claim based on Landlord's failure
to mitigate damages except as provided in the preceding sentence.
Notwithstanding the foregoing Washington State law shall prevail.

17.     LATE CHARGES

        Tenant hereby acknowledges that late payment by Tenant to Landlord of
rent and other sums due hereunder will cause Landlord to incur costs not
contemplated by this Lease, the exact amount of which will be extremely
difficult to ascertain. Such costs include, but are not limited to, processing
and accounting charges, and late charges which may be imposed on Landlord by the
terms of any mortgage or trust deed covering the Premises. Accordingly, if any
installment of rent or any other sum due from Tenant shall not be received by
Landlord or Landlord's designee within ten (10) days after such amount shall be
due, Tenant shall pay to Landlord a late charge equal to five percent (5%) of
such overdue amount. the parties hereby agree that such late charge represents a
fair and reasonable estimate of the costs Landlord will incur by reason of late
payment by Tenant. Acceptance of such late charge by Landlord shall in no event
constitute a waiver of Tenant's default with respect to such overdue amount, nor
prevent Landlord from exercising any of the other rights and remedies granted
hereunder. A twenty-five dollar ($25.00) charge shall be paid to Landlord for
any returned check.

18.     COSTS AND ATTORNEYS' FEES

        In the event of an action (or any appeal thereof) between the parties
hereto to enforce any of the terms or provisions of this Lease, the successful
party shall be entitled to recover from the unsuccessful party, in addition to
any other award, a reasonable sum as attorney fees to be determined by the court
and included as a part of the judgment.

19.     NON-WAIVER OF BREACH

        The failure of the Landlord to insist upon strict performance of any of
the covenants and agreements of this Lease, or to exercise any option herein
conferred in any one or more instances, shall not be construed to be a waiver or
relinquishment of any such, or any other covenants or agreements, but the same
shall be and remain in full force and effect.



                                       17

<PAGE>   18

20.     REMOVAL OF PROPERTY

        In the event of any entry in, or taking possession of, the leased
Premises as aforesaid, the Landlord shall have the right, which right shall not
be exercised unreasonably, but not the obligation, to remove from the leased
Premises all personal property located therein, and may store the same in any
place selected by Landlord, including but not limited to a public warehouse, at
the expense and risk of the owners thereof, with the right to sell such stored
property, without notice to Tenant, after it has been stored for a period of
thirty (30) days or more, the proceeds of such sale to be applied first to the
cost of such sale, second to the payment of the charges for storage, if any, and
third to the payment of any other sums of money which may then be due from
Tenant to Landlord under any of the terms hereof, the balance, if any, to be
paid to Tenant. Landlord shall not remove any property without reasonable
advance notice to Tenant.

21.     HEIRS AND SUCCESSORS

        Subject to the provisions hereof pertaining to Assignment and
Subletting, the covenants and agreements of this Lease shall be binding upon the
heirs, legal representatives, successors and assigns of any or all of the
parties hereto.

22.     HOLD OVER

        If the Tenant shall, with the written consent of Landlord, hold over
after the expiration of the Term of this Lease, such tenancy shall be for an
indefinite period of time on the month-to-month tenancy, which tenancy may be
terminated as provided by the laws of the State of Washington. During such
tenancy, Tenant agrees to pay to the Landlord the same rate of rental as set
forth herein, unless a different rate is agreed upon, and to be bound by all of
the terms, covenants, and conditions as herein specified, so far as applicable.
If Tenant shall, without the written consent of Landlord, hold over after the
expiration of the term of this Lease, such tenancy shall be month-to-month, on
the same terms and conditions as contained herein; provided, however, the rental
rate shall be one and one quarter that in effect during the last month of the
lease term.

23.     SUBORDINATION, QUIET ENJOYMENT

        This Lease is subject to and is hereby subordinated to all present and
future mortgages, deeds of trust and other encumbrances affecting the leased
Premises or the property of which said Premises are a part. Tenant will, upon
demand by Landlord, execute such instruments as may be required at any time, and
from time to time, to subordinate the rights and interests of the Tenant under
this Lease to the lien of any mortgage or trust deed at any time placed on the
land of which the leased Premises are a part, provided, however, that such
subordination shall not affect Tenant's right to possession, use and occupancy
of the leased Premises so long as Tenant shall not be in default under any of
the terms or conditions of this Lease, Tenant further agrees:

        That any such subordination agreement will contain a provision
satisfactory to Landlord's financing lender whereby Tenant will agree, in the
event of foreclosure of any such mortgage or trust deed to attorn to and
recognize as its Landlord under the terms of 



                                       18

<PAGE>   19

this Lease said lender or any purchaser of the leased property at a foreclosure
sale or their heirs, successors, or assigns, and that it will execute and
deliver to such lender an Estoppel Certificate in form satisfactory to such
lender.

24.     PERSONAL PROPERTY AND TRADE FIXTURES

        It is contemplated that certain furniture, fixtures and equipment to be
installed by Tenant in the leased Premises, are or may be either leased by
Tenant or purchased by Tenant from a lessor or conditional seller or otherwise
hypothecated to a third party. In this connection, it is agreed that all of such
furniture, fixtures and equipment installed by Tenant in the leased Premises
shall at all times be and remain personal property, regardless of the method in
which the same are affixed to the Premises, and shall remain the personal
property of Tenant and/or such third party. Landlord specifically agrees that
its rights, if any, in such furniture, fixtures and equipment shall at all times
be subject and subordinate to the rights of any such described third party.
Landlord agrees to execute, upon request, any documents reasonably required by
any such described third party in order to effectuate the purposes of this
paragraph, it being specifically agreed by Landlord herein that any such third
party shall have the right to remove the furniture, fixtures or equipment from
the leased Premises in the event of the default of Tenant in complying with its
agreements relating to such furniture, fixtures and equipment. Tenant agrees to
repair any damage caused by any such removal at its expense.

25.     CONDEMNATION

        If the Premises or any portion thereof are taken under the power of
eminent domain, or sold by Landlord under the threat of the exercise of said
power (all of which is referred to as "Condemnation"), this Lease shall
terminate as to the part so taken as of the date the condemning authority takes
title or possession, whichever occurs first. If more than ten percent (10%) of
the floor area of any buildings on the Premises, or more than twenty-five
percent (25%) of the land area of the Premises not covered with buildings, is
taken by Condemnation, either Landlord or Tenant may terminate this Lease as of
the date the condemning authority takes possession, by notice in writing of such
election within twenty (20) days after Landlord shall have notified Tenant of
the taking, or in the absence of such notice then within twenty (20) days after
the condemning authority shall have taken possession. If this Lease is not
terminated by either Landlord or Tenant, then it shall remain in full force and
effect as to the portion of the Premises remaining, provided the rent shall be
reduced in the proportion that the floor area of the buildings taken within the
Premises bears to the total floor area of all buildings located on the Premises.
In the event this Lease is not so terminated, then Landlord agrees, at
Landlord's sole cost, to restore the Premises to a complete unit of like quality
and character as existed prior to the condemnation as soon as reasonably
possible. All awards for the taking of any part of the Premises or any payment
made under the threat of the exercise of power of eminent domain shall be the
property of Landlord, whether made as compensation for diminution value of a
leasehold or for the taking of the fee or as severance damages; provided,
however, that Tenant shall be entitled to any award for loss of or damage to
Tenant's trade 



                                       19

<PAGE>   20

fixtures and removable personal property. In the event that this Lease is not
terminated by reason of such Condemnation, Landlord shall, to the extent of
severance damages received by Landlord in connection with such Condemnation,
repair any damage to the Premises caused by such Condemnation except to the
extent that Tenant has been reimbursed therefor by the condemning authority.

26.     NOTICES

        Wherever under this Lease provision is made for any demand, notice or
declaration of any kind, or where it is deemed desirable or necessary by either
party to give or serve any such notice, demand or declaration to the other
party, it shall be in writing and served either personally or sent by United
States mail, postage prepaid, addressed to the address set forth herein below:

        Landlord:                                         Tenant:

        The Evans Company                                 Optiva Corporation

        1457 130th Ave NE                                 13226 SE 30th St B-1

        Bellevue WA 98005                                 Bellevue WA 98005

27.     CORPORATE AUTHORITY

        If Tenant is a corporation, each individual executing this Lease on
behalf of said corporation represents and warrants that he is duly authorized to
execute and deliver this Lease on behalf of said corporation in accordance with
a duly adopted resolution of the Board of Directors of said corporation or in
accordance with the by-laws of said corporation, and that this Lease is binding
upon said corporation in accordance with its terms. If Tenant is a corporation
Tenant shall, within thirty (30) days after execution of this Lease, deliver to
Landlord a certified copy of a resolution of the Board of Directors of said
corporation substantially the same as or identical to Exhibit D authorizing or
ratifying the execution of this Lease.

28.     MISCELLANEOUS

        28.1 TRANSFER OF LANDLORD'S INTEREST. In the event of a sale or
conveyance by Landlord of Landlord's interest in the Premises other than a
transfer for security purposes only, Landlord shall be relieved from, after the
date specified in such notice of transfer, all obligations and liabilities
accruing thereafter on the part of the Landlord, provided that any funds in the
hands of Landlord at the time of transfer in which Tenant has an interest, shall
be delivered to the successor of Landlord. This Lease shall not be affected by
any such sale and Tenant agrees to attorn to the purchaser or assignee, provided
all Landlord's obligations hereunder are assumed in writing by the transferee.

        28.2 SEVERABILITY. If any term or provision of this Lease shall, to any
extent, be determined by a court of competent jurisdiction to be invalid or
unenforceable, the 



                                       20

<PAGE>   21

remainder of this Lease shall not be affected thereby, and each term and
provision of this Lease shall be valid and be enforceable to the fullest extent
permitted by law.

        28.3 TIME; JOINT AND SEVERAL LIABILITY. Time is of the essence of this
Lease and each and every provision hereof, except as to the conditions relating
to the delivery of possession of the Premises to Tenant. All the terms,
covenants and conditions contained in this Lease to be performed by either
party, if such party shall consist of more than one person or organization,
shall be deemed to be Joint and Several, and all rights and remedies of the
parties shall be cumulative and non-exclusive of any other remedy at law or in
equity.

        28.4 MEMORANDUM OF LEASE. This Lease shall not be recorded, but upon
written request of Landlord or Tenant, a Memorandum of Lease describing the
Premises, giving ale term of this Lease and the name and address of Landlord and
Tenant, referring to this Lease, and in form suitable under law as record
notice, shall be promptly executed, acknowledged and delivered by both parties;
such Memorandum of Lease may be recorded by either party.

29.     HAZARDOUS AND TOXIC WASTE MATERIALS

        Tenant shall be fully responsible for any release of any hazardous waste
or substance in or on or under the Premises or on any adjacent property during
the lease term by Tenant, Tenant's officers, directors, successors, assigns,
subleases, guests, invitees, visitors, employees, agents, contractors or any
other person or entity in or about the Premises. Tenant shall promptly comply
with all statutes, regulations and ordinances and with all orders, decrees or
judgments of governmental authorities or courts having jurisdiction relating to
the use, collection, treatment, disposal, storage, control, removal or cleanup
of hazardous waste or substances in, on or under the Premises or any adjacent
property or incorporated in any of the improvements, at Tenant's sole expense.
After notice to Tenant and a reasonable opportunity for Tenant to affect such
compliance, Landlord may, but shall not be obligated to, enter upon the Premises
and take such actions and incur such costs and expenses to affect such
compliance as it deems advisable to protect its interest in the Premises;
provided however, Landlord shall not be obligated to give Tenant notice and
opportunity to affect compliance if (i) such delay might result in material
adverse harm to Landlord or the Premises; (ii) Tenant has already had actual
knowledge of the situation and a reasonable opportunity to affect compliance; or
(iii) an emergency exists. Whether or not Tenant has actual knowledge of the
release of hazardous waste or substances on the Premises or any adjacent
property as a result of Tenant's use of the Premises, Tenant shall reimburse
Landlord for the full amount of all costs and expenses incurred by Landlord in
connection with such compliance activities, and such obligation shall survive
any termination of this Lease. Tenant shall notify Landlord immediately of any
release of any hazardous waste or substance on the Premises. Tenant shall
indemnify and hold Landlord harmless from any and all losses, liabilities,
suits, obligations, fines, damages, judgments, penalties, claims, charges,
cleanup costs, remedial actions, costs and expenses (including, without
limitation, attorneys fees and disbursements) which may be 



                                       21

<PAGE>   22

imposed on, incurred or paid by, or asserted against Landlord or the Premises by
reason of (i) any misrepresentation, breach of warranty or other default by
Tenant under this Lease resulting in the release of any hazardous waste or
substance or (ii) the act or omissions of Tenant, Tenant's officers, directors,
successors, assigns, subleases, guests, invitees, visitors, employees, agents,
contractors or any other person whatsoever other than Landlord resulting in the
release of any hazardous waste or materials in, on or under the Premises or any
adjacent property. Landlord may perform any inspections, audits or surveys of
the Premises as Landlord deems necessary or advisable at any time during the
term of this Lease.

30.     SPECIAL ARTICLES

        The following numbered sections are made a part hereof, N/A , and appear
below on Addendums N/A attached hereto. The following Exhibit(s) not referenced
in the lease above are also made a part hereof, D, E , and are attached hereto.

        In Witness Whereof, the Landlord and Tenant have executed this Lease the
date and year first above written.


Landlord:                                         Tenant:

By: /s/ Scott Evans                               By: /s/ David Giuliani
    --------------------------                        --------------------------
        Vice President                                  Optiva Corp.   Pres/CEO
    --------------------------                        --------------------------



                                       22

<PAGE>   23



                                    LANDLORD


                                    CORPORATE
STATE OF WASHINGTON)
                                    ss.
COUNTY OF KING   )

On this 11 day of October, in the year 1995, before me Edward T. Babbitt, the
undersigned Notary Public, personally appeared Scott Evans, personally known to
me (or proved to me on the basis of satisfactory evidence) to be the person who
executed the within instrument as VICE PRESIDENT on behalf of THE EVANS COMPANY,
the corporation therein named, and acknowledged to me that the corporation
executed it.

/s/ Edward T. Babbitt                         Residing At Redmond.
-----------------------------                             ---------------------
Notary's Signature


================================================================================
                                   PARTNERSHIP

STATE OF WASHINGTON)
                                    ss.
COUNTY OF KING   )

On this ______ day of _______________ , in the year 19___, before
me______________________________ , the undersigned Notary Public, personally
appeared _____________________________________ , personally known to me to be
the person who executed the within instrument on behalf of the partnership and
acknowledged to me that the partnership executed it.



___________________________                   Residing At______________________.
Notary's Signature


                                     TENANT


                                    CORPORATE
STATE OF WASHINGTON)
                                    ss.
COUNTY OF KING   )



                                       23

<PAGE>   24

On this ______ day of ________________, in the year 19___, before me
___________________________________ , the undersigned Notary Public, personally
appeared _____________________________________ , personally known to me (or
proved to me on the basis of satisfactory evidence) to be the person who
executed the within instrument as _________________________________ on behalf of
---------------------, the corporation therein named, and acknowledged to me
that the corporation executed it.

___________________________                   Residing At______________________.
Notary's Signature



================================================================================
                                   PARTNERSHIP
STATE OF WASHINGTON)
                                    ss.
COUNTY OF KING   )

On this ______ day of ________________, in the year 19___, before me
____________________________________, the undersigned Notary Public, personally
appeared _____________________________________ , personally known to me to be
the person who executed the within instrument on behalf of the partnership and
acknowledged to me that the partnership executed it.

___________________________                   Residing At______________________.
Notary's Signature


================================================================================
                                   INDIVIDUAL
STATE OF WASHINGTON)
                                    ss.
COUNTY OF KING   )

On this________day of_________________, in the year 19___, before me
______________________________, personally appeared ___________________________,
personally known to me (or proved to me on the basis of satisfactory evidence)
to be the person(s) whose name(s) is(are) subscribed to this instrument, and
acknowledged to me that he(she) executed it. WITNESS my hand and official seal.


___________________________                   Residing At______________________.
Notary's Signature



                                       24