<PAGE>

                                                                   Exhibit 10-15


                                                                  EXECUTION COPY





                          REGISTRATION RIGHTS AGREEMENT

                                     Between

                                 ActivCard S.A.

                                       and

                             SUN MICROSYSTEMS, INC.


                          Dated as of February 3, 2000


<PAGE>


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>

                                                                                               PAGE

<S>         <C>                                                                                <C>
SECTION 1.  Definitions ..........................................................................1
SECTION 2.  Notice of Proposed Transfer ..........................................................2
SECTION 3.  Piggyback Registration ...............................................................3
SECTION 4.  Registrations of Form F-3 or S-3 .................................................... 4
SECTION 5.  Holdback Agreement ...................................................................5
SECTION 6.  Preparation and Filing ...............................................................6
SECTION 7.  Expenses .............................................................................9
SECTION 8.  Indemnification ......................................................................9
SECTION 9.  Underwriting Agreement ..............................................................12
SECTION 10. Information by Holders of Registrable Shares ........................................12
SECTION 11. Exchange Act Compliance .............................................................12
SECTION 12. No-Action Letter or Opinion of Counsel in Lieu of Registration.......................12
SECTION 13. Termination .........................................................................13
SECTION 14. Successors and Assigns ..............................................................13
SECTION 15. Assignment ..........................................................................13
SECTION 16. Entire Agreement ....................................................................13
SECTION 17. Notices .............................................................................14
SECTION 18. Modifications; Amendments; Waivers ..................................................15
SECTION 19. Counterparts; Facsimile Signatures ..................................................15
SECTION 20. Headings ............................................................................15
SECTION 21. Severability; Governing Law .........................................................15
SECTION 22. Survival ............................................................................16

</TABLE>
<PAGE>

                  REGISTRATION RIGHTS AGREEMENT, dated as of February 3, 2000
(this "AGREEMENT"), between ActivCard S.A., a French SOCIETE ANONYME
("ACTIVCARD"), and Sun Microsystems, Inc., a Delaware corporation ("SUN
MICROSYSTEMS").


                                 R E C I T A L S

                  WHEREAS, pursuant to a stock purchase agreement dated the date
hereof (the "STOCK PURCHASE AGREEMENT"), Sun Microsystems has agreed to purchase
582,750 newly issued Ordinary Shares (as defined below) from ActivCard;

                  WHEREAS, the execution of this Agreement is a condition to the
purchase of the Ordinary Shares by Sun Microsystems pursuant to the Stock
Purchase Agreement;

                  NOW, THEREFORE, the parties hereby agree as follows:

                  SECTION 1. DEFINITIONS.  As used in this Agreement, the
following terms shall have the following meanings:

                  "COMMISSION" means the U.S. Securities and Exchange
Commission or any successor agency.

                  "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended, and the rules and regulations of the Commission promulgated thereunder,
all as the same shall be in effect from time to time.

                  "ORDINARY SHARES" means the ordinary shares, FF 6.25 nominal
value per share, of ActivCard.

                  "OTHER SHARES" means at any time those Ordinary Shares which
do not constitute Primary Shares or Registrable Shares.

                  "PERSON" means an individual, corporation, partnership,
limited partnership, syndicate, person (including, without limitation, a
"person" as defined in Section 13(d)(3) of the Exchange Act), trust, association
or entity or government, political subdivision, agency or instrumentality of a
government.

                  "PRIMARY SHARES" means at any time the authorized but unissued
Ordinary Shares and Ordinary Shares held by ActivCard in its treasury.
<PAGE>

                  "REGISTRATION DATE" means the date upon which a registration
statement pursuant to which ActivCard shall have initially registered Ordinary
Shares under the Securities Act for sale to the public shall have been declared
effective.

                  "REGISTRABLE SHARES" means the Ordinary Shares issued to Sun
Microsystems pursuant to the Stock Purchase Agreement and any securities issued
with respect to such Ordinary Shares pursuant to any stock split, stock
dividend, recapitalization, substitution or other similar transaction. For
purposes of this Agreement, any Registrable Shares shall cease to be Registrable
Shares (i) when they have been registered under the Securities Act (the
registration statement in connection therewith has been declared effective) and
disposed of pursuant to such effective registration statement, (ii) when they
are sold by a person in a transaction in which the rights under the provisions
of this Agreement are not assigned, (iii) when they have been sold or
distributed pursuant to Rule 144 (including, without limitation, Rule 144(k)) or
(iv) on the last day of any three-month period within which they may be sold or
distributed without registration pursuant to Rule 144.

                   "RULE 144" means Rule 144 promulgated under the Securities
Act or any successor rule thereto or any complementary rule thereto (such as
Rule 144A).

                  "SECURITIES ACT" means the Securities Act of 1933, as amended,
and the rules and regulations of the Commission promulgated thereunder, all as
the same shall be in effect from time to time.

                  "STOCK PURCHASE AGREEMENT" has the meaning set forth
in the recitals to this Agreement.

                  SECTION 2. NOTICE OF PROPOSED TRANSFER.

                  Prior to any proposed transfer of any Registrable Shares
(other than under the circumstances described in Sections 3 or 4 hereof), the
holder thereof shall have given written notice to ActivCard of its intention to
effect such transfer. Each such notice shall describe the manner of the proposed
transfer and, if requested by ActivCard, shall be accompanied by an opinion of
counsel satisfactory to ActivCard to the effect that the proposed transfer may
be effected without registration under the Securities Act, whereupon the holder
of such Registrable Shares shall be entitled to transfer such Registrable Shares
in accordance with the terms of its notice. Additionally, all such transfers
shall be made pursuant to the Letter Agreement the date hereof among Paribas,
ActivCard and Sun Microsystems, or any other similar letter agreement required
to be entered into by subsequent holders of the Registrable Shares. Sun
Microsystems' compliance with Section 3.5 of the Stock Purchase Agreement shall
be deemed to be compliance with the notice requirements of this Section 2.


                                       2
<PAGE>

                  SECTION 3. PIGGYBACK REGISTRATION.



                  (a) If ActivCard at any time proposes for any reason to
register Ordinary Shares under the Securities Act (other than a registration
relating to the initial public offering of Ordinary Shares by Activcard
(including Ordinary Shares in the form of American Depositary Shares) in the
United States, a registration relating solely to employee benefit plans, or a
registration on registration statement Form F-4, Form S-4 or any registration
form which does not permit secondary sales or does not include substantially the
same information as would be required to be included in a registration statement
covering the sale of Registrable Securities, in each case, promulgated under the
Securities Act or any successor forms thereto), it shall give written notice to
the holders of Registrable Shares of its intention to so register such Ordinary
Shares at least 30 days before the initial filing of such registration
statement. Upon the written request of the holders of Registrable Shares to
include Registrable Shares in such registration (which request (i) must be
delivered to ActivCard within 15 days after delivery by ActivCard of any notice
pursuant to this Section 3(a), (ii) shall specify the number of Registrable
Shares proposed to be included in such registration and (iii) shall state that
such holders of Registrable Shares desire to sell such Registrable Shares in the
public securities markets), ActivCard shall use its best efforts to cause all
such Registrable Shares to be included in such registration on the same terms
and conditions as the securities otherwise being sold in such registration;
PROVIDED, HOWEVER, that if the managing underwriter advises ActivCard that the
inclusion of all Registrable Shares proposed to be included in such registration
would interfere with the successful marketing (including pricing) of the Primary
Shares or Other Shares proposed to be registered by ActivCard, then the number
of Primary Shares, Registrable Shares and/or Other Shares proposed to be
included in such registration shall be included in the following order:

                  (i) first, the Primary Shares and any Ordinary Shares owned by
         Ken Fineman as of such date; and

                  (ii) second, the Registrable Shares and Other Shares requested
         to be included in such registration (or, if necessary, such Registrable
         Shares and Other Shares PRO RATA among the holders thereof based upon
         the aggregate number of Registrable Shares and Other Shares requested
         to be registered by each such holder).

                  (b) If the registration of which ActivCard gives notice is for
an underwritten registered public offering, ActivCard shall so advise the
holders as part of the written notice given pursuant to Section 3(a). In such
event, the right of any holder to registration pursuant to this Section 3 shall
be conditioned upon such holder's participation in such underwritten offering
and the inclusion of such holder's Registrable Securities in the underwritten
offering to the extent provided herein. All holders proposing to distribute
Registrable Shares through such underwritten offering shall (together with
ActivCard and the other shareholders distributing their securities through such
underwritten offering) enter into an underwriting agreement in customary form
with the underwriter selected by ActivCard. If any holder disapproves of the
terms of any such underwritten offering, he may elect to withdraw therefrom by
written notice to ActivCard


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<PAGE>

and the underwriter. Any Registrable Securities or other securities excluded
or withdrawn from such underwritten offering shall be withdrawn from such
registration.

                  (c)      The number of requests permitted by the holders
of Registrable Shares pursuant to this Section 3 shall be unlimited.

                  SECTION 4. REGISTRATIONS ON FORM F-3 OR S-3.

                  (a)      At such time as ActivCard shall have qualified for
the use of Form F-3 or Form S-3, as the case may be, promulgated under the
Securities Act or any successor forms thereto, the holders of the Registrable
Shares then outstanding shall have the right to request in writing that
ActivCard effect the registration of Registrable Shares in the form of ADSs on
Form F-3 or Form S-3, as the case may be, or such successor form, which request
or requests shall (i) specify the number of Registrable Shares intended to be
sold or disposed of and the holders thereof and (ii) state the intended method
of disposition of such Registrable Shares. ActivCard shall promptly use its best
efforts to effect the registration under the Securities Act of such Registrable
Shares which ActivCard has been so requested to register; PROVIDED, HOWEVER,
that ActivCard shall be required to effect a registration pursuant to this
Section 4(a) only if the holders of not less than 70% of the Registrable Shares
then outstanding shall have stated in writing a desire to sell at least 50% of
the Registrable Shares held by them in a registration pursuant to this Section
4(a). If ActivCard determines to have the Registrable Shares distributed by
means of an underwritten offering, ActivCard and the requesting holders shall
enter into an underwriting agreement with a major bracket or nationally known
underwriter.

                  (b)      Anything contained in Section 4(a) to the contrary
notwithstanding, ActivCard shall not be obligated to effect any registration
under the Securities Act pursuant to Section 3(a) except in accordance with the
following provisions:

                  (i)      ActivCard shall not be obligated to use its best
         efforts to file and cause to become effective any registration
         statement during any period in which any other registration statement
         (other than on Form F-4 or Form S-4, as the case may be, or Form F-8 or
         Form S-8, as the case may be, promulgated under the Securities Act or
         any successor forms thereto) pursuant to which Primary Shares, Other
         Shares or Registrable Shares included pursuant to Section 2 are to be
         or were sold has been filed and not withdrawn or has been declared
         effective within the prior 90 days.

                  (ii)     ActivCard may delay or suspend the filing or
         effectiveness of any registration statement for two periods of up to 60
         days after the date of a request for registration pursuant to this
         Section 4 if at the time of such request (i) ActivCard is engaged, or
         has fixed plans to engage within 90 days of the time of such request,
         in a firm commitment underwritten public offering of Primary Shares in
         which the holders of Registrable Shares may include Registrable Shares
         pursuant to Section 3 or (ii) ActivCard reasonably determines that such
         registration and offering would interfere with any material transaction
         involving ActivCard, as approved by the Board of Directors, or if


                                       4
<PAGE>

         there exists at the time, material non-public information relating
         to ActivCard, which in the opinion of ActivCard, should not be
         disclosed or if the sale of shares thereunder would, in the opinion of
         ActivCard, be reasonably likely to cause a violation of the Securities
         Act or the Exchange Act and result in potential liability to
         ActivCard; PROVIDED, HOWEVER, that ActivCard may only delay or suspend
         the filing or effectiveness of a registration statement pursuant to
         this Section 4(b)(ii) for a total of 120 days after the date of a
         request for registration pursuant to this Section 4; and PROVIDED,
         further, that ActivCard may only delay or suspend the filing or
         effectiveness of a registration statement pursuant to this Section
         4(b)(ii) not more than once in any twelve (12) month period.

                  (iii)    With respect to any registration pursuant to this
         Section 4, ActivCard shall give notice of such registration to the
         holders of Registrable Shares who do not request registration
         hereunder. ActivCard shall include in such registration any Registrable
         Shares requested, within 10 days after ActivCard has given such notice,
         to be included by such holders and may include in such registration any
         Primary Shares or Other Shares; PROVIDED, HOWEVER, that if the managing
         underwriter advises ActivCard that the inclusion of all Registrable
         Shares, Primary Shares and/or Other Shares proposed to be included in
         such registration would interfere with the successful marketing
         (including pricing) of the Registrable Shares proposed to be included
         in such registration, then the number of Registrable Shares, Primary
         Shares and/or Other Shares proposed to be included in such registration
         shall be included in the following order:

                           (A) first, the Registrable Shares and any Ordinary
                  Shares owned by Ken Fineman as of such date requested to be
                  included in such registration (or, if necessary, such
                  Registrable Shares and Ordinary Shares owned by Ken Fineman
                  PRO RATA among the holders thereof based upon the aggregate
                  number of Registrable Shares and Ordinary Shares owned by Ken
                  Fineman requested to be registered by each such holder);

                           (B) second, the Other Shares requested to be
                  included in such registration (or, if necessary, such Other
                  Shares PRO RATA among the holders thereof based upon the
                  aggregate number of Other Shares requested to be registered by
                  each such holder), and

                           (C) third, the Primary Shares.

                  (c)      Two requests shall be permitted by the holders
         of Registrable Shares pursuant to this Section 4.

                  SECTION 5.   HOLDBACK AGREEMENT.

                  If ActivCard at any time shall register Ordinary Shares under
the Securities Act


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<PAGE>

(including any registration pursuant to Sections 3 or 4 hereof) for sale to the
public, Sun Microsystems shall not sell publicly or privately, make any short
sale of, grant any option for the purchase of, or otherwise dispose publicly of,
any Registrable Shares (other than those Ordinary Shares included in such
registration pursuant to Sections 3 or 4 hereof) without the prior written
consent of ActivCard, for a period as shall be determined by the relevant
managing underwriters, which period shall begin not more than 10 days prior to
the initial filing of the registration statement pursuant to which such public
offering shall be made and shall not last more than 180 days after the effective
date of such registration statement. Sun Microsystems shall be subject to the
holdback restrictions of this Section 4 only once in any twelve-month period
during the term of this Agreement.

                  SECTION 6. PREPARATION AND FILING.

                  (a)      If and whenever ActivCard is under an obligation
pursuant to the provisions of this Agreement to use its best efforts to effect
the registration of any Registrable Shares, ActivCard shall, as expeditiously as
practicable:

                  (i)      use its best efforts to cause a registration
         statement that registers such Registrable Shares to become and remain
         effective for a period of 90 days or until all of such Registrable
         Shares have been disposed of (if earlier). ActivCard shall not be
         required to maintain the effectiveness of any registration statement
         that contemplates a distribution of securities on a delayed or
         continuous basis pursuant to Rule 415 under the Securities Act;

                  (ii)     furnish, at least five business days before filing a
         registration statement, to counsel designated by Sun Microsystems
         ("INVESTOR'S COUNSEL"), a copy of the registration statement proposed
         to be filed and the prospectus relating thereto or any amendments or
         supplements relating to such a registration statement or prospectus (it
         being understood that such five-business-day period need not apply to
         successive drafts of the same document proposed to be filed so long as
         such successive drafts are supplied to the Investor's Counsel in
         advance of the proposed filing by a period of time that is reasonable
         under the circumstances);

                  (iii)    prepare and file with the Commission such amendments
         and supplements to such registration statement and the prospectus
         relating thereto as may be necessary to keep such registration
         statement effective for at least a period of 90 days or until all of
         such Registrable Shares have been disposed of (if earlier) and to
         comply with the provisions of the Securities Act with respect to the
         sale or other disposition of such Registrable Shares;

                  (iv)     provide written notice to Investor's Counsel
         concerning (i) the receipt by ActivCard of any comments of the
         Commission with respect to such registration statement or prospectus
         or any amendment or supplement thereto or any request by the


                                       6
<PAGE>

         Commission for the amending or supplementing thereof or for additional
         information with respect thereto, (ii) the receipt by ActivCard of any
         notification with respect to the issuance by the Commission of any
         stop order suspending the effectiveness of such registration statement
         or prospectus or any amendment or supplement thereto or the initiation
         or threatening of any proceeding for that purpose and (iii) the
         receipt by ActivCard of any notification with respect to the
         suspension of the qualification of such Registrable Shares for sale in
         any jurisdiction or the initiation or threatening of any proceeding
         for such purposes;

                  (v)      use its best efforts to register or qualify such
         Registrable Shares under such other securities or blue sky laws of such
         jurisdictions as the holders of the Registrable Shares reasonably
         request and do any and all other acts and things which may be
         reasonably necessary or advisable to enable such holders to consummate
         the disposition in such jurisdictions of such holders' Registrable
         Shares; PROVIDED, HOWEVER, that ActivCard will not be required (i) to
         qualify generally to do business, subject itself to general taxation or
         consent to general service of process in any jurisdiction where it
         would not otherwise be required to do so but for this paragraph (v),
         (ii) to provide any material undertaking or make any changes in its
         charter documents which the Board of Directors determines to be
         contrary to the best interests of ActivCard or (iii) to modify any of
         its contractual relationships then existing;

                  (vi)     furnish to the holders of such Registrable Shares
         such number of copies of a summary prospectus, if any, or other
         prospectus, including a preliminary prospectus, in conformity with the
         requirements of the Securities Act, and such other documents as such
         holders may reasonably request in order to facilitate the public sale
         or other disposition of such Registrable Shares;

                  (vii)    notify the holders of such Registrable Shares on a
         timely basis of the happening of any event as a result of which a
         prospectus included in the registration statement relating to such
         Registrable Shares, as then in effect, includes an untrue statement of
         a material fact or omits to state a material fact required to be stated
         therein or necessary to make the statements therein not misleading in
         light of the circumstances then existing and, at the request of such
         holders, prepare and furnish to such holders a reasonable number of
         copies of a supplement to or an amendment of such prospectus as may be
         necessary to cause such prospectus, as so supplemented or amended, not
         to include an untrue statement of a material fact or omit to state a
         material fact required to be stated therein or necessary to make the
         statements therein not misleading in light of the circumstances then
         existing;

                  (viii)   subject to the execution of confidentiality
         agreements in form and substance satisfactory to ActivCard and upon
         reasonable notice and during normal business hours, make available for
         inspection by the holders of such Registrable Shares, any underwriter
         participating in any disposition pursuant to such registration
         statement


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<PAGE>

         and any attorney, accountant or other agent retained by Sun
         Microsystems or the underwriter (collectively, the "INSPECTORS"), all
         pertinent financial and other records, pertinent corporate documents
         and properties of ActivCard (collectively, the "RECORDS"), as shall be
         reasonably necessary to enable them to exercise their due diligence
         responsibility, and cause ActivCard's officers, directors and
         employees to supply all information (together with the Records, the
         "INFORMATION") reasonably requested by any such Inspector in
         connection with such registration statement. Notwithstanding the
         foregoing, any of the Information which ActivCard determines in good
         faith to be confidential, and of which determination the Inspectors
         are so notified, shall not be disclosed to or by the Inspectors unless
         (i) the disclosure of such Information is necessary to avoid or
         correct a misstatement or omission in the registration statement, (ii)
         the release of such Information is ordered pursuant to a subpoena or
         other order from a court of competent jurisdiction or (iii) such
         Information is generally available to the public other than as a
         result of disclosure by the Inspectors; the holders of such
         Registrable Shares agree that they will, upon learning that disclosure
         of such Information is sought in a court of competent jurisdiction,
         give notice to ActivCard and allow ActivCard, at ActivCard's expense,
         to undertake appropriate action to prevent disclosure of the
         Information deemed confidential; and the Inspectors shall use best
         efforts to maintain the confidentiality of all Information disclosed
         pursuant to this Section 6(a)(viii);

                  (ix)     use its best efforts to obtain from its independent
         certified public accountants "cold comfort" letters in customary form,
         at customary times and covering matters of the type customarily covered
         by cold comfort letters;

                  (x)      use its best efforts to obtain from its counsel an
         opinion or opinions in customary form;

                  (xi)     provide a transfer agent and registrar (which may be
         the same entity and which may be ActivCard) for such Registrable
         Shares;

                  (xii)    list such Registrable Shares or American Depositary
         Shares representing such Registrable Shares, as the case may be, on any
         national securities exchange on which any Ordinary Shares or American
         Depositary Shares representing Ordinary Shares are listed;

                  (xiii)   otherwise use its best efforts to comply with all
         applicable rules and regulations of the Commission and make available
         to its security holders, as soon as reasonably practicable, earnings
         statements (which need not be audited) covering a period of 12 months
         beginning within three months after the effective date of the
         registration statement, which earnings statements shall satisfy the
         provisions of Section 11(a) of the Securities Act; and

                  (xiv)    subject to all the other provisions of this
         Agreement, use its reasonable best efforts to take all other steps
         necessary to effect such registration of such Registrable Shares
         contemplated hereby (including, without limitation, if the method of
         distribution is by means of an underwriting agreement in customary
         form).


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<PAGE>

                  (b)      Each holder of the Registrable Shares, upon receipt
of any notice from ActivCard of any event of the kind described in Section
6(a)(vii) hereof, shall forthwith discontinue disposition of the Registrable
Shares pursuant to the registration statement covering such Registrable
Shares until such holder's receipt of the copies of the supplemented or
amended prospectus contemplated by Section 6(a)(vii) hereof, and, if so
directed by ActivCard, such holder shall deliver to ActivCard all copies,
other than permanent file copies then in such holder's possession, of the
prospectus covering such Registrable Shares at the time of receipt of such
notice.

                  SECTION 7. EXPENSES.

                  All expenses (other than underwriting discounts and
commissions relating to the Registrable Shares, as provided in the last sentence
of this Section 7) incurred by ActivCard in complying with Section 6, including,
without limitation, all registration and filing fees (including all expenses
incident to filing with the National Association of Securities Dealers, Inc.),
fees and expenses of complying with securities and blue sky laws, printing
expenses, fees and expenses of ActivCard's counsel and accountants and
reasonable fees and expenses (not to exceed U.S. $20,000) of the Investor's
Counsel, shall be paid by ActivCard; PROVIDED, HOWEVER, that all underwriting
discounts and selling commissions applicable to the Registrable Shares and Other
Shares shall be borne by the holders selling such Registrable Shares and Other
Shares, in proportion to the number of Registrable Shares and Other Shares sold
by each such holder.

                  SECTION 8. INDEMNIFICATION.

                  (a)      In connection with any registration of any
Registrable Shares under the Securities Act pursuant to this Agreement,
ActivCard shall indemnify and hold harmless the holders of Registrable
Shares, each underwriter, broker or any other Person acting directly on
behalf of the holders of Registrable Shares in connection with the
distribution thereof and each other Person, if any, who controls any of the
foregoing Persons within the meaning of the Securities Act against any
losses, claims, damages or liabilities, joint or several (or actions in
respect thereof), to which any of the foregoing Persons may become subject
under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are
based upon an untrue statement or allegedly untrue statement of a material
fact contained in the registration statement under which such Registrable
Shares were registered under the Securities Act, any preliminary prospectus
or final prospectus contained therein or otherwise filed with the Commission,
any amendment or supplement thereto or any document incident to registration
or qualification of any Registrable Shares, or arise out of or are based upon
the omission or alleged omission to state therein a material fact required to
be stated therein or necessary to make the statements therein not misleading
or, with respect to any prospectus, necessary to make the statements therein
in light of the circumstances under which they were made not misleading, or
any violation by ActivCard of the Securities Act or state securities or blue
sky laws applicable to ActivCard and relating to action or inaction required
of ActivCard in connection with such registration or qualification under such
state securities or blue sky laws; and ActivCard shall reimburse the holders
of Registrable Shares, such underwriter,


                                       9
<PAGE>

such broker or such other Person acting on behalf of the holders of
Registrable Shares and each such controlling Person for any legal or other
expenses reasonably incurred by any of them in connection with investigating
or defending any such loss, claim, damage, liability or action; PROVIDED,
HOWEVER, that ActivCard shall not be liable in any such case to the extent
that any such loss, claim, damage, liability or action (including any legal
or other expenses incurred) arises out of or is based upon an untrue
statement or allegedly untrue statement or omission or alleged omission made
in said registration statement, preliminary prospectus, final prospectus,
amendment, supplement or document incident to registration or qualification
of any Registrable Shares in reliance upon and in conformity with written
information furnished to ActivCard through an instrument duly executed by the
holders of Registrable Shares or their counsel or underwriter specifically
for use in the preparation thereof; PROVIDED FURTHER, HOWEVER, that the
foregoing indemnity agreement is subject to the condition that, insofar as it
relates to any untrue statement, allegedly untrue statement, omission or
alleged omission made in any preliminary prospectus but eliminated or
remedied in the final prospectus (filed pursuant to Rule 424 of the
Securities Act), such indemnity agreement shall not inure to the benefit of
any holder of Registrable Shares, underwriter, broker or other Person acting
on behalf of holders of Registrable Shares from whom the Person asserting any
loss, claim, damage, liability or expense purchased the Registrable Shares
which are the subject thereof, if a copy of such final prospectus had been
made available to such holder of Registrable Shares, underwriter, broker or
other Person acting on behalf of holders of the Registrable Shares and such
final prospectus was not delivered to such Person with or prior to the
written confirmation of the sale of such Registrable Shares to such Person,
and the legal effect of delivery of such final prospectus would have been to
eliminate the liability otherwise suffered or incurred by the Person
asserting such loss, claim, damage, liability or expense.

                  (b)      In connection with any registration of Registrable
Shares under the Securities Act pursuant to this Agreement, each holder of
Registrable Shares shall severally and not jointly indemnify and hold
harmless ActivCard, each director of ActivCard, each officer of ActivCard who
shall sign such registration statement, each underwriter, broker or other
Person acting on behalf of the holders of Registrable Shares and each Person
who controls any of the foregoing Persons within the meaning of the
Securities Act against any losses, claims, damages or liabilities, joint or
several (or actions in respect thereof), to which any of the foregoing
Persons may become subject under the Securities Act or otherwise, insofar as
such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based upon an untrue statement or allegedly untrue
statement of a material fact contained in the registration statement under
which such Registrable Shares were registered under the Securities Act, any
preliminary prospectus or final prospectus contained therein or otherwise
filed with the Commission, any amendment or supplement thereto or any
document incident to registration or qualification of any Registrable Shares,
or arise out of or are based upon the omission or alleged omission to state
therein a material fact required to be stated therein or necessary to make
the statements therein not misleading or, with respect to any prospectus,
necessary to make the statements therein in light of the circumstances under
which they were made not misleading, if such untrue statement or allegedly
untrue statement or omission or alleged omission was made in reliance upon
and in conformity with written information furnished to ActivCard or such
underwriter by or on behalf


                                       10
<PAGE>

of such holder of Registrable Shares specifically for use in connection with
the preparation of such registration statement, preliminary prospectus, final
prospectus, amendment, supplement or document; PROVIDED, HOWEVER, that the
maximum amount of liability in respect of such indemnification shall be
limited, in the case of each seller of Registrable Shares, to an amount equal
to the net proceeds actually received by such seller from the sale of
Registrable Shares effected pursuant to such registration.

                  (c)      Promptly after receipt by an indemnified party of
notice of the commencement of any action involving a claim referred to in the
preceding paragraphs of this Section 8, such indemnified party will, if a claim
in respect thereof is made against an indemnifying party, give written notice to
the latter of the commencement of such action. The failure of any indemnified
party to notify an indemnifying party of any such action shall not (unless such
failure shall have a material adverse effect on the indemnifying party) relieve
the indemnifying party from any liability in respect of such action that it may
have to such indemnified party on account of this Section 8. In case any such
action is brought against an indemnified party, the indemnifying party will be
entitled to participate in and to assume the defense thereof, jointly with any
other indemnifying party similarly notified to the extent that it may wish, with
counsel reasonably satisfactory to such indemnified party, and after notice from
the indemnifying party to such indemnified party of its election so to assume
the defense thereof, the indemnifying party shall not be responsible for any
legal or other expenses subsequently incurred by the indemnified party in
connection with the defense thereof; PROVIDED, HOWEVER, that if any indemnified
party shall have reasonably concluded that there may be one or more legal or
equitable defenses available to such indemnified party which are additional to
or conflict with those available to the indemnifying party, or that such claim
or litigation involves or could have an effect upon matters beyond the scope of
the indemnity agreement provided in this Section 8, the indemnifying party shall
not have the right to assume the defense of such action on behalf of such
indemnified party (but shall have the right to participate therein with counsel
of its choice) and such indemnifying party shall reimburse such indemnified
party for that portion of the reasonable fees and expenses of any counsel
retained by the indemnified party which is reasonably related to the matters
covered by the indemnity agreement provided in this Section 8. If the
indemnifying party is not entitled to, or elects not to, assume the defense of a
claim or series of claims of all indemnified parties, it will not be obligated
to pay the fees and expenses of more than one counsel with respect to all
indemnified parties as to any claim or series of related claims. The
indemnifying party may not settle any such claim without the consent of the
indemnified party.

                  (d)      If the indemnification provided for in this
Section 8 is held by a court of competent jurisdiction to be unavailable to
an indemnified party with respect to any loss, claim, damage, liability or
action referred to herein, then the indemnifying party, in lieu of
indemnifying such indemnified party hereunder, shall contribute to the
amounts paid or payable by such indemnified party as a result of such loss,
claim, damage, liability or action in such proportion as is appropriate to
reflect the relative fault of the indemnifying party on the one hand and of
the indemnified party on the other in connection with the statements or
omissions which resulted in such loss, claim, damage, liability or action as
well as any other relevant equitable


                                       11
<PAGE>

considerations. The relative fault of the indemnifying party and of the
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the indemnifying party or by the indemnified party and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission. The parties agree that it
would not be just and equitable if contribution pursuant hereto were
determined by PRO RATA allocation or by any other method or allocation which
does not take account of the equitable considerations referred to herein. No
Person guilty of fraudulent misrepresentation shall be entitled to
contribution from any Person.

                  SECTION 9. UNDERWRITING AGREEMENT.

                  Notwithstanding the provisions of Sections 5, 6, 7 and 8, to
the extent that the holders of Registrable Shares shall enter into an
underwriting or similar agreement, which agreement contains provisions covering
one or more issues addressed in such Sections, the provisions contained in such
agreement addressing such issue or issues shall control; PROVIDED, HOWEVER, that
any such agreement to which ActivCard is not a party shall not be binding upon
ActivCard. No holder may participate in any underwritten registration hereunder
unless such holder (a) agrees to sell such holders' securities on the basis
provided in any underwriting arrangements and (b) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements and
other documents reasonably and customarily required under the terms of such
underwriting arrangements.

                  SECTION 10. INFORMATION BY HOLDERS OF REGISTRABLE SHARES.

                  Each holder of Registrable Shares shall furnish to ActivCard
such written information regarding such Person and the distribution proposed by
such Person as ActivCard may reasonably request in writing and as shall be
reasonably required in connection with any registration, qualification or
compliance referred to in this Agreement.

                  SECTION 11. EXCHANGE ACT COMPLIANCE.

                  From the Registration Date or such earlier date as a
registration statement filed by ActivCard pursuant to the Exchange Act
relating to any class of ActivCard's securities shall have become effective,
ActivCard shall comply with all of the reporting requirements of the Exchange
Act applicable to it and shall comply with all other public information
reporting requirements of the Commission which are conditions to the
availability of Rule 144 for the sale of the Common Stock. ActivCard shall
cooperate with each holder of Registrable Shares in supplying such
information as may be necessary for such holder to complete and file any
information reporting forms presently or hereafter required by the Commission
as a condition to the availability of Rule 144.

                  SECTION 12.  NO-ACTION LETTER OR OPINION OF COUNSEL IN LIEU OF
REGISTRATION.


                                       12
<PAGE>

                  Notwithstanding anything in this Agreement in the contrary, if
at any time after the date of ActivCard's initial public offering of its
securities under the Securities Act ActivCard shall have obtained from the
Commission a "no-action" letter in which the Commission has indicated that it
will take no action if, without registration under the Securities Act, any
holder disposes of Registrable Shares covered by any request for registration
made under this Agreement in the manner in which such holder proposes to dispose
of the Registrable Shares included in such request, or if in the opinion of
counsel for ActivCard concurred in by counsel for such holder no registration
under the Securities Act is required in connection with such disposition, the
Registrable Shares included in such request shall not be eligible for
registration under this Agreement; provided, however, with respect to any holder
who may deemed to be an "affiliate," as that term is defined under Rule 144, if,
notwithstanding the opinion of such counsel, the holder is unable to dispose of
all the Registrable Shares included in his request in the manner in which such
holder so proposes without registration, the Registrable Shares included in such
request shall be eligible for registration under this Agreement.

                  SECTION 13. TERMINATION.

                  All registration rights granted under this Agreement shall
terminate and be of no further force and effect upon the earlier of (i) two (2)
years after the Registration Date and (ii) the date on which all of the
Registrable Shares cease to be Registrable Shares hereunder.

                  SECTION 14. SUCCESSORS AND ASSIGNS.

                  This Agreement shall bind and inure to the benefit of
ActivCard and Sun Microsystems and, subject to Section 15, their respective
successors and assigns.

                  SECTION 15. ASSIGNMENT.

                  Sun Microsystems may assign its rights hereunder to any of its
affiliates to which it transfers Registrable Shares; PROVIDED, HOWEVER, that
such transferee shall, as a condition to the effectiveness of such assignment,
be required to execute a counterpart to this Agreement agreeing to be treated as
a holder of Registrable Shares whereupon such purchaser or transferee shall have
the benefits of, and shall be subject to the restrictions contained in, this
Agreement as if such transferee had originally been a party hereto; and
PROVIDED, FURTHER, that such transferee shall not be a competitor of ActivCard
(as determined by the Board of Directors of ActivCard).

                  SECTION 16. ENTIRE AGREEMENT.

                  This Agreement, the Stock Purchase Agreement and the other
writings referred to herein and therein or delivered pursuant hereto or thereto,
contain the entire agreement among Sun Microsystems, ActivCard and any other
parties to each of the foregoing with respect to the subject matter hereof and
supersede all prior and contemporaneous arrangements or understandings with
respect thereto.


                                       13
<PAGE>

                  SECTION 17. NOTICES.

                  (a)      All notices, requests, consents and other
communications hereunder to any party shall be deemed to be sufficient if
contained in a written instrument delivered in person or sent by telecopy,
nationally-recognized overnight courier or first class registered or certified
mail, return receipt requested, postage prepaid, addressed to such party at the
address set forth below or such other address as may hereafter be designated in
writing by such party to the other parties:

                  (i)      if to ActivCard, to:

                           ActivCard S.A.
                           6531 Dumbarton Circle
                           Fremont, CA  94555
                           Telephone: (510) 574-0100
                           Telecopy: (510) 574-0128
                           Attention: Jean-Gerard Galvez;

                           with a copy to:

                           Shearman & Sterling
                           599 Lexington Avenue
                           New York, NY 10022
                           Telephone: (212) 848-7620
                           Telecopy: (212) 848-7179
                           Attention: Richard B. Vilsoet;

                  (ii)     if to Sun Microsystems, to:

                           Sun Microsystems, Inc.
                           901 San Antonio Road
                           MS UMPK16-302
                           Palo Alto, California 94303
                           Telephone: (650) 786-5533
                           Facsimile: (650) 786-2581

                           Attention: Jonathan I. Schwartz;

                           with a copy to:

                           Sun Microsystems, Inc.
                           901 San Antonio Road
                           Palo Alto, California 94303
                           Telephone: (650) 960-1300
                           Facsimile: (650) 856-2114
                           Attention: General Counsel; and


                                       14
<PAGE>

                  (b)      All such notices, requests, consents and other
communications shall be deemed to have been delivered (a) in the case of
personal delivery or delivery by telecopy, on the date of such delivery, (b) in
the case of dispatch by nationally-recognized overnight courier, on the next
business day following such dispatch and (c) in the case of mailing, on the
third business day after the posting thereof.

                  SECTION 18. MODIFICATIONS; AMENDMENTS; WAIVERS.

                  The terms and provisions of this Agreement may not be modified
or amended, nor may any provision be waived, except pursuant to a writing
signed, in the case of an amendment or modification, by holders of more than 50%
of the Registrable Shares that are entitled to registration rights hereunder, or
in the case of a waiver, by the party against whom the waiver is to be
effective.

                  SECTION 19. COUNTERPARTS; FACSIMILE SIGNATURES.

                  This Agreement may be executed in any number of counterparts
(including by telecopy), and each such counterpart hereof shall be deemed to be
an original instrument, but all such counterparts together shall constitute but
one agreement.

                  SECTION 20. HEADINGS.

                  The headings of the various sections of this Agreement have
been inserted for convenience of reference only and shall not be deemed to be a
part of this Agreement.

                  SECTION 21. SEVERABILITY; GOVERNING LAW.

                  It is the desire and intent of the parties that the
provisions of this Agreement be enforced to the fullest extent permissible
under the laws and public policies applied in each jurisdiction in which
enforcement is sought. Accordingly, if any particular provision of this
Agreement shall be adjudicated by a court of competent jurisdiction to be
invalid, prohibited or unenforceable for any reason, such provision, as to
such jurisdiction, shall be ineffective, without invalidating the remaining
provisions of this Agreement or affecting the validity or enforceability of
this Agreement or affecting the validity or enforceability of such provision
in any other jurisdiction. Notwithstanding the foregoing, if such provision
could be more narrowly drawn so as not to be invalid, prohibited or
unenforceable in such jurisdiction, it shall, as to such jurisdiction, be so
narrowly drawn, without invalidating the remaining provisions of this
Agreement or affecting the validity or enforceability of such provision in
any other jurisdiction. This Agreement shall be governed by and construed in
accordance with the laws of the State of New York applicable to contracts
made and to be performed wholly therein.


                                       15
<PAGE>

                  SECTION 22. SURVIVAL.

                  The respective agreements, covenants, indemnities and other
statements set forth in Section 8 hereof shall remain in full force and effect,
regardless of any termination or cancellation of this Agreement.


                                       16
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have executed
this Agreement on the date first written above.


                                     ActivCard S.A.



                                     By: /s/ JQ GALVEZ
                                        ----------------------------------------
                                     Name: JQ GLAVEZ
                                     Title: CE


                                     SUN MICROSYSTEMS, INC.


                                     By: /s/ JONATHON SCHWARTZ
                                        ----------------------------------------
                                     Name: JONATHON SCHWARTZ
                                     Title: VP


                                       17