<PAGE>   1


                               OPTIVA CORPORATION

                              AMENDED AND RESTATED
                             1990 STOCK OPTION PLAN


SECTION 1.  PURPOSE

        The purpose of the Optiva Corporation Amended and Restated 1990 Stock
Option Plan (this "Plan") is to provide a means whereby selected employees,
directors, officers, agents, consultants, advisors and independent contractors
of Optiva Corporation, a Washington corporation (the "Company"), or of any
parent or subsidiary (as defined in subsection 5.8 and referred to hereinafter
as "related corporations") thereof, may be granted incentive stock options
and/or nonqualified stock options to purchase the Common Stock (as defined in
Section 3) of the Company, in order to attract and retain the services or advice
of such employees, directors, officers, agents, consultants, advisors and
independent contractors and to provide added incentive to such persons by
encouraging stock ownership in the Company.

SECTION 2.  ADMINISTRATION

        This Plan shall be administered by the Board of Directors of the Company
(the "Board") or a committee or committees (which term includes subcommittees)
appointed by, and consisting of two or more members of, the Board (the "Plan
Administrator"). If and so long as the Common Stock is registered under Section
12(b) or 12(g) of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), the Board shall consider, in selecting the Plan Administrator and the
membership of any committee acting as the Plan Administrator of this Plan with
respect to any persons subject or likely to become subject to Section 16 under
the Exchange Act, the provisions regarding (a) "outside directors," as
contemplated by Section 162(m) of the Internal Revenue Code of 1986, as amended
(the "Code") and (b) "nonemployee directors," as contemplated by Rule 16b-3
under the Exchange Act. The Board may delegate the responsibility for
administering this Plan with respect to designated classes of eligible
participants to different committees, subject to such limitations as the Board
deems appropriate. The members of any committee serving as the Plan
Administrator shall be appointed by the Board for such term as the Board may
determine. The Board may from time to time remove members from, or add members
to, any committee. Vacancies on a committee, however caused, shall be filled by
the Board.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 1
<PAGE>   2

        2.1    PROCEDURES

        The Board shall designate one of the members of the Plan Administrator
as chairman. The Plan Administrator may hold meetings at such times and places
as it shall determine. The acts of a majority of the members of the Plan
Administrator present at meetings at which a quorum exists, or acts reduced to
or approved in writing by all Plan Administrator members, shall be valid acts of
the Plan Administrator.

        2.2    RESPONSIBILITIES

        Except for the terms and conditions explicitly set forth in this Plan,
the Plan Administrator shall have the authority, in its discretion, to determine
all matters relating to the options to be granted under this Plan, including
selection of the individuals to be granted options, the number of shares to be
subject to each option, the exercise price, and all other terms and conditions
of the options. Grants under this Plan need not be identical in any respect,
even when made simultaneously. The interpretation and construction by the Plan
Administrator of any terms or provisions of this Plan or any option issued
hereunder, or of any rule or regulation promulgated in connection herewith,
shall be conclusive and binding on all interested parties, so long as such
interpretation and construction with respect to incentive stock options
correspond to the requirements of Section 422 of the Code, the regulations
thereunder and any amendments thereto.

        2.3    SECTION 16

        Notwithstanding anything in this Plan to the contrary, the Board, in its
absolute discretion, may bifurcate this Plan so as to restrict, limit or
condition the application of any provision of this Plan to participants who are
subject to Section 16 of the Exchange Act without so restricting, limiting or
conditioning this Plan with respect to other participants.

SECTION 3.  SHARES SUBJECT TO THIS PLAN

        The shares subject to this Plan shall be the Company's Common Stock (the
"Common Stock"), currently authorized but unissued or subsequently acquired by
the Company. Subject to adjustment as provided in Section 7, the aggregate
amount of Common Stock to be delivered upon the exercise of all options granted
under this Plan 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 2
<PAGE>   3
 shall not exceed 4,800,000 shares(1). If any option granted under this Plan
shall expire or be surrendered, exchanged for another option, cancelled or
terminated for any reason without having been exercised in full, the unpurchased
shares subject thereto shall thereupon again be available for purposes of this
Plan.

SECTION 4.  ELIGIBILITY

        An incentive stock option may be granted only to an individual who, at
the time the option is granted, is an employee of the Company or a related
corporation. A nonqualified stock option may be granted to any employee,
director, officer, agent, consultant, advisor or independent contractor of the
Company or any related corporation, whether an individual or an entity. Any
party to whom an option is granted under this Plan shall be referred to
hereinafter as an "Optionee."

SECTION 5.  TERMS AND CONDITIONS OF OPTIONS

        Options granted under this Plan shall be evidenced by written agreements
which shall contain such terms, conditions, limitations and restrictions as the
Plan Administrator shall deem advisable and which are not inconsistent with this
Plan. Notwithstanding the foregoing, options shall include or incorporate by
reference the following terms and conditions:

        5.1    NUMBER OF SHARES AND PRICE

        The maximum number of shares that may be purchased pursuant to the
exercise of each option and the price per share at which such option is
exercisable (the "exercise price") shall be as established by the Plan
Administrator; provided that the Plan Administrator shall act in good faith to
establish an exercise price which shall be not less than the fair market value
per share of the Common Stock at the time the option is granted with respect to
incentive stock options and not less than 85% of the fair market value of the
Common Stock at the time the option is granted with respect to nonqualified
stock options, and also provided that, with respect to incentive stock options
granted to greater than 10% shareholders, the exercise price shall be as
required by subsection 6.1.

        5.2    TERM AND MATURITY

        Subject to the restrictions contained in Section 6 with respect to
granting incentive stock options to greater than 10% shareholders, the term of
each incentive 


--------
(1)     This number reflects the stock split in connection with the offering.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 3

<PAGE>   4

stock option shall be as established by the Plan Administrator and, if not so
established, shall be 10 years from the date it is granted but in no event shall
it exceed 10 years. The term of each nonqualified stock option shall be as
established by the Plan Administrator and, if not so established, shall be 10
years. To ensure that the Company or a related corporation will achieve the
purpose and receive the benefits contemplated by this Plan, any option granted
to any Optionee hereunder shall, unless the condition of this sentence is waived
or modified in the agreement evidencing the option or by resolution adopted at
any time by the Plan Administrator, be exercisable according to the following
schedule:

<TABLE>
<CAPTION>
          Period of Optionee's Continuous
          Relationship With the Company or
          Related Corporation From the Date    Portion of Total Option
          the Option Is Granted                Which Is Exercisable
          -------------------------------------------------------------
<S>                                            <C>
          after one year                       25%

          after two years                      50%

          after three years                    75%

          after four years                     100%
</TABLE>

        5.3    EXERCISE

        Subject to the vesting schedule described in subsection 5.2, each option
may be exercised in whole or in part at any time and from time to time; provided
that only whole shares will be issued pursuant to the exercise of any option. An
option shall be exercised by delivery to the Company of notice of the number of
shares with respect to which the option is exercised, together with payment of
the exercise price.

        5.4    PAYMENT OF EXERCISE PRICE

        Payment of the option exercise price shall be made in full at the time
the notice of exercise of the option is delivered to the Company and shall be in
cash, bank certified or cashier's check, or personal check (unless at the time
of exercise the Plan Administrator in a particular case determines not to accept
a personal check) for the shares being purchased.

        The Plan Administrator can determine at any time before exercise that
additional forms of payment will be permitted. To the extent permitted by the
Plan Administrator and applicable laws and regulations (including, but not
limited to, federal tax and securities laws and regulations and state corporate
law), an option may be exercised by:



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 4
<PAGE>   5

               (a) delivery of shares of Common Stock of the Company held by an
Optionee having a fair market value equal to the exercise price, such fair
market value to be determined in good faith by the Plan Administrator; provided,
however, that payment in stock held by an Optionee shall not be made unless the
stock shall have been owned by the Optionee for a period of at least six months;

               (b) delivery of a full-recourse promissory note executed by the
Optionee; provided that (i) such note delivered in connection with an incentive
stock option shall, and such note delivered in connection with a nonqualified
stock option may, in the sole discretion of the Plan Administrator, bear
interest at a rate specified by the Plan Administrator but in no case less than
the rate required to avoid imputation of interest (taking into account any
exceptions to the imputed interest rules) for federal income tax purposes, (ii)
the Plan Administrator in its sole discretion shall specify the term and other
provisions of such note at the time an incentive stock option is granted or at
any time prior to exercise of a nonqualified stock option, (iii) the Plan
Administrator may require that the Optionee pledge to the Company for the
purpose of securing the payment of such note the shares of Common Stock to be
issued to the Optionee upon exercise of the option and may require that the
certificate representing such shares be held in escrow in order to perfect the
Company's security interest, and (iv) the Plan Administrator in its sole
discretion may at any time restrict or rescind this right upon notification to
the Optionee; or

               (c) delivery of a properly executed exercise notice, together
with irrevocable instructions to a broker, all in accordance with the
regulations of the Federal Reserve Board, to promptly deliver to the Company the
amount of sale or loan proceeds to pay the exercise price and any federal, state
or local withholding tax obligations that may arise in connection with the
exercise.

        5.5    WITHHOLDING TAX REQUIREMENT

        The Company or any related corporation shall have the right to retain
and withhold from any payment of cash or shares of Common Stock under this Plan
the amount of taxes required by any government to be withheld or otherwise
deducted and paid with respect to such payment. At its discretion, the Company
may require an Optionee receiving shares of Common Stock to reimburse the
Company for any such taxes required to be withheld by the Company and withhold
any distribution in whole or in part until the Company is so reimbursed. In lieu
thereof, the Company shall have the right to withhold from any other cash
amounts due or to become due from the Company to the Optionee an amount equal to
such taxes. The Company may also retain and withhold or the Optionee may elect,
subject to approval by the Company at its sole discretion, to have the Company
retain and withhold a number of shares 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 5
<PAGE>   6

having a market value not less than the amount of such taxes required to be
withheld by the Company to reimburse the Company for any such taxes and cancel
(in whole or in part) any such shares so withheld.

        5.6    HOLDING PERIODS

               5.6.1     SECURITIES AND EXCHANGE ACT SECTION 16

        If an individual subject to Section 16 of the Exchange Act sells shares
of Common Stock obtained upon the exercise of a stock option within six months
after the date the option was granted, such sale may result in short-swing
profit recovery under Section 16(b) of the Exchange Act.

               5.6.2     TAXATION OF STOCK OPTIONS

        In order to obtain certain tax benefits afforded to incentive stock
options under Section 422 of the Code, an Optionee must hold the shares issued
upon the exercise of an incentive stock option for two years after the date of
grant of the option and one year from the date of exercise. An Optionee may be
subject to the alternative minimum tax at the time of exercise of an incentive
stock option.

        The Plan Administrator may require an Optionee to give the Company
prompt notice of any disposition of shares acquired by the exercise of an
incentive stock option prior to the expiration of such holding periods.

        Tax advice should be obtained by an Optionee when exercising any option
and prior to the disposition of the shares issued upon the exercise of any
option.

        5.7    TRANSFERABILITY OF OPTIONS

        Options granted under this Plan and the rights and privileges conferred
hereby may not be transferred, assigned, pledged or hypothecated in any manner
(whether by operation of law or otherwise) other than by will or by the
applicable laws of descent and distribution and shall not be subject to
execution, attachment or similar process. During an Optionee's lifetime, any
options granted under this Plan are personal to him or her and are exercisable
solely by such Optionee. Any attempt to transfer, assign, pledge, hypothecate or
otherwise dispose of any option under this Plan or of any right or privilege
conferred hereby, contrary to the Code or to the provisions of this Plan, or the
sale or levy or any attachment or similar process upon the rights and privileges
conferred hereby shall be null and void. Notwithstanding the foregoing, to the
extent permitted by Section 422 of the Code and any applicable law or
regulation, the Plan Administrator may permit an Optionee to (a) during the
Optionee's lifetime, designate 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 6
<PAGE>   7

a person who may exercise the option after the Optionee's death by giving
written notice of such designation to the Company (such designation may be
changed from time to time by the Optionee by giving written notice to the
Company revoking any earlier designation and making a new designation) or (b)
with respect to nonqualified stock options, transfer the option and the rights
and privileges conferred hereby; provided, however, that any option so assigned
or transferred shall be subject to all the same terms and conditions contained
in the instrument evidencing the option.

        5.8    TERMINATION OF RELATIONSHIP

        If the Optionee's relationship with the Company or any related
corporation ceases for any reason other than termination for cause, death or
total disability, and unless by its terms the option sooner terminates or
expires, then the Optionee may exercise, for a three-month period, that portion
of the Optionee's option which is exercisable at the time of such cessation, but
the Optionee's option shall terminate at the end of such period following such
cessation as to all shares for which it has not theretofore been exercised,
unless such provision is waived in the agreement evidencing the option. If, in
the case of an incentive stock option, an Optionee's relationship with the
Company or any related corporation changes (i.e., from employee to nonemployee,
such as a consultant), such change shall constitute a termination of an
Optionee's employment with the Company or any related corporation and the
Optionee's incentive stock option shall terminate in accordance with this
subsection 5.8. Upon the expiration of the three-month period following
cessation of employment in the case of an incentive stock option, or at any time
prior to the expiration of the option in the case of a nonqualified stock
option, the Plan Administrator shall have sole discretion in a particular
circumstance to extend the exercise period following such cessation to any date
up to the termination or expiration of the option. If, however, in the case of
an incentive stock option, the Optionee does not exercise the Optionee's option
within three months after cessation of employment, the option will no longer
qualify as an incentive stock option under the Code.

        If an Optionee is terminated for cause, each option granted hereunder
shall automatically terminate as of the first discovery by the Company of any
reason for termination for cause, and such Optionee shall thereupon have no
right to purchase any shares pursuant to such option. "Termination for cause"
shall mean dismissal for dishonesty, conviction or confession of a crime (except
minor violations), fraud, misconduct or disclosure of confidential information.
If an Optionee's relationship with the Company or any related corporation is
suspended pending an investigation of whether or not the Optionee shall be
terminated for cause, the Optionee's rights under 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 7
<PAGE>   8

each option granted hereunder likewise shall be suspended during the period of
investigation.

        If an Optionee's relationship with the Company or any related
corporation ceases because of a total disability, the Optionee's option shall
not terminate or, in the case of an incentive stock option, cease to be treated
as an incentive stock option until the end of the 12-month period following such
cessation (unless by its terms it sooner terminates or expires). As used in this
Plan, the term "total disability" refers to a mental or physical impairment of
the Optionee which is expected to result in death or which has lasted or is
expected to last for a continuous period of 12 months or more and which causes
the Optionee to be unable, in the opinion of the Company and two independent
physicians, to perform his or her duties for the Company and to be engaged in
any substantial gainful activity. Total disability shall be deemed to have
occurred on the first day after the Company and the two independent physicians
have furnished their opinion of total disability to the Plan Administrator.

        Options granted under the Plan shall not be affected by any change of
relationship with the Company so long as the Optionee continues to be an
employee, director, officer, agent, consultant, advisor or independent
contractor of the Company or of a related corporation; however, a change in an
Optionee's status from an employee to a nonemployee (e.g., consultant or
independent contractor) shall result in the termination of an outstanding
incentive stock option held by such Optionee. The Plan Administrator, in its
absolute discretion, may determine all questions of whether particular leaves of
absence constitute a termination of services; provided, however, that with
respect to incentive stock options, such determination shall be subject to any
requirements contained in the Code. The foregoing notwithstanding, with respect
to incentive stock options, employment shall not be deemed to continue beyond
the first 90 days of such leave, unless the Optionee's reemployment rights are
guaranteed by statute or by contract.

        As used herein, the term "related corporation," when referring to a
subsidiary corporation, shall mean any corporation (other than the Company) in,
at the time of the granting of the option, an unbroken chain of corporations
ending with the Company, if stock possessing 50% or more of the total combined
voting power of all classes of stock of each of the corporations other than the
Company is owned by one of the other corporations in such chain. When referring
to a parent corporation, the term "related corporation" shall mean any
corporation in an unbroken chain of corporations ending with the Company if, at
the time of the granting of the option, each of the corporations other than the
Company owns stock possessing 50% or more of the total combined voting power of
all classes of stock in one of the other corporations in such chain.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 8
<PAGE>   9

        5.9    DEATH OF OPTIONEE

        If an Optionee dies while he or she has a relationship with the Company
or any related corporation or within the three-month period (or 12-month period
in the case of totally disabled Optionees) following cessation of such
relationship, any option held by such Optionee to the extent that the Optionee
would have been entitled to exercise such option, may be exercised within one
year after his or her death by the personal representative of his or her estate
or by the person or persons to whom the Optionee's rights under the option shall
pass (a) by will or by the applicable laws of descent and distribution or (b) by
a designation or transfer pursuant to Section 5.7.

        5.10   NO STATUS AS SHAREHOLDER

        Neither the Optionee nor any party to which the Optionee's rights and
privileges under the option may pass shall be, or have any of the rights or
privileges of, a shareholder of the Company with respect to any of the shares
issuable upon the exercise of any option granted under this Plan unless and
until such option has been exercised.

        5.11   CONTINUATION OF RELATIONSHIP

        Nothing in this Plan or in any option shall confer upon any Optionee any
right to continue in the employ or other relationship of the Company or of a
related corporation, or to interfere in any way with the right of the Company or
of any such related corporation to terminate his or her employment or other
relationship with the Company at any time.

        5.12   MODIFICATION AND AMENDMENT OF OPTION

        Subject to the requirements of Code Section 422 with respect to
incentive stock options and to the terms and conditions and within the
limitations of this Plan, the Plan Administrator may modify or amend any
outstanding option granted under this Plan. The modification or amendment of an
outstanding option shall not, without the consent of the Optionee, impair or
diminish any of his or her rights or any of the obligations of the Company under
such option. Except as otherwise provided in this Plan, no outstanding option
shall be terminated without the consent of the Optionee.

        5.13   LIMITATION ON VALUE FOR INCENTIVE STOCK OPTIONS

        As to all incentive stock options granted under the terms of this Plan,
to the extent that the aggregate fair market value of the shares (determined at
the time the incentive stock option is granted) with respect to which incentive
stock options are 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                               Page 9
<PAGE>   10

exercisable for the first time by the Optionee during any calendar year (under
this Plan and all other incentive stock option plans of the Company, a related
corporation or a predecessor corporation) exceeds $100,000, such options shall
be treated as nonqualified stock options. The previous sentence shall not apply
if the Internal Revenue Service issues a public rule, issues a private ruling to
the Company, any Optionee or any legatee, personal representative or distributee
of an Optionee or issues regulations changing or eliminating such annual limit.

SECTION 6.  GREATER THAN 10% SHAREHOLDERS

        6.1    EXERCISE PRICE AND TERM OF INCENTIVE STOCK OPTIONS

        If an incentive stock option is granted under this Plan to any employee
who owns more than 10% of the total combined voting power of all classes of
stock of the Company or any related corporation, the term of such incentive
stock options shall not exceed five years and the exercise price shall be not
less than 110% of the fair market value of the shares at the time the incentive
stock option is granted. This provision shall control notwithstanding any
contrary terms contained in an option agreement or any other document.

        6.2    ATTRIBUTION RULE

        For purposes of subsection 6.1, in determining stock ownership, an
employee shall be deemed to own the shares owned, directly or indirectly, by or
for his or her brothers, sisters, spouse, ancestors and lineal descendants.
Shares owned, directly or indirectly, by or for a corporation, partnership,
estate or trust shall be deemed to be owned proportionately by or for its
shareholders, partners or beneficiaries. If an employee or a person related to
the employee owns an unexercised option or warrant to purchase shares of the
Company, the shares subject to that portion of the option or warrant which is
unexercised shall not be counted in determining stock ownership. For purposes of
this Section 6, shares owned by an employee shall include all shares actually
issued and outstanding immediately before the grant of the incentive stock
option to the employee.

SECTION 7.  ADJUSTMENTS UPON CHANGES IN CAPITALIZATION

        The aggregate number and class of shares for which options may be
granted under this Plan, the number and class of shares covered by each
outstanding option and the exercise price per share thereof (but not the total
price), and each such option, shall all be proportionately adjusted for any
increase or decrease in the number of issued shares of Common Stock of the
Company resulting from a split-up or 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                              Page 10
<PAGE>   11

consolidation of shares or any like capital adjustment, or the payment of any
stock dividend.

        7.1    EFFECT OF LIQUIDATION OR REORGANIZATION

               7.1.1  CASH, STOCK OR OTHER PROPERTY FOR STOCK

        Except as provided in subsection 7.1.2, upon a merger (other than a
merger of the Company in which the holders of shares of Common Stock immediately
prior to the merger have the same proportionate ownership of shares of Common
Stock in the surviving corporation immediately after the merger), consolidation,
acquisition of property or stock, separation, reorganization (other than a mere
reincorporation or the creation of a holding company) or liquidation of the
Company, as a result of which the shareholders of the Company receive cash,
stock or other property in exchange for or in connection with their shares of
Common Stock, any option granted hereunder shall terminate, but the Optionee
shall have the right immediately prior to any such merger, consolidation,
acquisition of property or stock, separation, reorganization or liquidation to
exercise such Optionee's option in whole or in part whether or not the vesting
requirements set forth in the option agreement have been satisfied; provided
that such acceleration will not occur if, in the opinion of the Company's
outside accountants, such acceleration would render unavailable "pooling of
interests" accounting treatment for any reorganization, merger or consolidation
of the Company for which pooling of interests accounting treatment is sought by
the Company.

               7.1.2  CONVERSION OF OPTIONS ON STOCK FOR STOCK EXCHANGE

        If the shareholders of the Company receive capital stock of another
corporation ("Exchange Stock") in exchange for their shares of Common Stock in
any transaction involving a merger (other than a merger of the Company in which
the holders of Common Stock immediately prior to the merger have the same
proportionate ownership of Common Stock in the surviving corporation immediately
after the merger), consolidation, acquisition of property or stock, separation
or reorganization (other than a mere reincorporation or the creation of a
holding company), all options granted hereunder shall be converted into options
to purchase shares of Exchange Stock unless the Company and the corporation
issuing the Exchange Stock, in their sole discretion, determine that any or all
such options granted hereunder shall not be converted into options to purchase
shares of Exchange Stock but instead shall terminate in accordance with the
provisions of subsection 7.1.1. The amount and price of converted options shall
be determined by adjusting the amount and price of the options granted hereunder
in the same proportion as used for determining the number of shares of Exchange
Stock the holders of the shares of Common Stock 



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                              Page 11
<PAGE>   12

receive in such merger, consolidation, acquisition of property or stock,
separation or reorganization. The converted options shall be fully vested
whether or not the vesting requirements set forth in the option agreement have
been satisfied; provided that such acceleration will not occur if, in the
opinion of the Company's outside accountants, such acceleration would render
unavailable "pooling of interests" accounting treatment for any reorganization,
merger or consolidation of the Company for which pooling of interests accounting
treatment is sought by the Company.

        7.2    FRACTIONAL SHARES

        In the event of any adjustment in the number of shares covered by any
option, any fractional shares resulting from such adjustment shall be
disregarded and each such option shall cover only the number of full shares
resulting from such adjustment.

        7.3    DETERMINATION OF BOARD TO BE FINAL

        All Section 7 adjustments shall be made by the Board, and its
determination as to what adjustments shall be made, and the extent thereof,
shall be final, binding and conclusive. Unless an Optionee agrees otherwise, any
change or adjustment to an incentive stock option shall be made in such a manner
so as not to constitute a "modification" as defined in Code Section 424(h) and
so as not to cause his or her incentive stock option issued hereunder to fail to
continue to qualify as an incentive stock option as defined in Code Section
422(b).

SECTION 8.  SECURITIES REGULATION

        Shares shall not be issued with respect to an option granted under this
Plan unless the exercise of such option and the issuance and delivery of such
shares pursuant thereto shall comply with all relevant provisions of law,
including, without limitation, any applicable state securities laws, the
Securities Act of 1933, as amended, the Exchange Act, the rules and regulations
promulgated thereunder, and the requirements of any stock exchange upon which
the shares may then be listed, and shall be further subject to the approval of
counsel for the Company with respect to such compliance, including the
availability, if applicable, of an exemption from registration for the issuance
and sale of any shares hereunder. Inability of the Company to obtain, from any
regulatory body having jurisdiction, the authority deemed by the Company's
counsel to be necessary for the lawful issuance and sale of any shares hereunder
or the unavailability of an exemption from registration for the issuance and
sale of any shares hereunder shall relieve the Company of any liability in
respect of the nonissuance or sale of such shares as to which such requisite
authority shall not have been obtained.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                              Page 12
<PAGE>   13

        As a condition to the exercise of an option, the Company may require the
Optionee to represent and warrant at the time of any such exercise that the
shares are being purchased only for investment and without any present intention
to sell or distribute such shares if, in the opinion of counsel for the Company,
such a representation is required by any relevant provision of the
aforementioned laws. At the option of the Company, a stop-transfer order against
any shares of stock may be placed on the official stock books and records of the
Company, and a legend indicating that the stock may not be pledged, sold or
otherwise transferred, unless an opinion of counsel is provided (concurred in by
counsel for the Company) stating that such transfer is not in violation of any
applicable law or regulation, may be stamped on stock certificates in order to
assure exemption from registration. The Plan Administrator may also require such
other action or agreement by the Optionees as may from time to time be necessary
to comply with the federal and state securities laws. THIS PROVISION SHALL NOT
OBLIGATE THE COMPANY TO UNDERTAKE REGISTRATION OF THE OPTIONS OR STOCK
HEREUNDER.

        Should any of the Company's capital stock of the same class as the stock
subject to options granted hereunder be listed on a national securities
exchange, all stock issued hereunder if not previously listed on such exchange
shall be authorized by that exchange for listing thereon prior to the issuance
thereof.

SECTION 9.  AMENDMENT AND TERMINATION

        9.1    BOARD ACTION

        The Board may at any time suspend, amend or terminate this Plan,
provided that, to the extent required for compliance with Section 422 of the
Code or by any applicable law or regulation, the Company's shareholders must
approve any amendment which will:

               (a) increase the number of shares that may be issued under this
Plan;

               (b) with respect to incentive stock options, change the
designation of the participants or class of participants eligible for
participation in this Plan; or

               (c) otherwise require shareholder approval under any applicable
law or regulation.

        Such shareholder approval must be obtained within 12 months of the
adoption by the Board of such amendment.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                              Page 13

<PAGE>   14

        Any amendment made to this Plan which would constitute a "modification"
to incentive stock options outstanding on the date of such amendment, shall not
be applicable to such outstanding incentive stock options, but shall have
prospective effect only, unless the Optionee agrees otherwise.

        9.2    AUTOMATIC TERMINATION

        Unless sooner terminated by the Board, this Plan shall terminate ten
years from the earlier of (a) the date on which this Plan is adopted by the
Board or (b) the date on which this Plan is approved by the shareholders of the
Company. No option may be granted after such termination or during any
suspension of this Plan. The amendment or termination of this Plan shall not,
without the consent of the option holder, alter or impair any rights or
obligations under any option theretofore granted under this Plan.

SECTION 10.  EFFECTIVENESS OF THIS PLAN

        This Plan shall become effective upon adoption by the Board so long as
it is approved by the Company's shareholders at any time within 12 months of
such adoption of this Plan.

Plan adopted by the Board of Directors on July 27, 1990 and approved by the
shareholders on August 15, 1990. Amended by the Board of Directors on October 8,
1992 and approved by the shareholders on October 22, 1992. Amended by the Board
of Directors on December 15, 1994 and approved by the shareholders on April 8,
1995. Amended and Restated by the Board on August 4, 1995 and approved by the
shareholders on August 24, 1995. Amended by the Board of Directors on April 15,
1996 and approved by the shareholders on April 27, 1996. Amended by the Board of
Directors on March 25, 1997 and approved by the shareholders on April 5, 1997.
Amended and Restated by the Board of Directors on ____________, 1998.



--------------------------------------------------------------------------------
Amended and Restated 1990 Stock Option Plan                              Page 14