<PAGE>
                                                                    Exhibit 99.6

(FIDELITY INVESTMENT(R) LOGO)

                                     10B5-1 TRADING PLAN-CLIENT INSTRUCTION FORM
                                    FOR TRADING IN SECURITIES IN COMPLIANCE WITH
                                    RULE 10B5-1 UNDER THE SECURITIES ACT OF 1933

    PLEASE CALL 800-544-6161 FOR ANY ASSISTANCE THAT YOU MAY REQUIRE WITH THE
                   COMPLETION OF THIS CLIENT INSTRUCTION FORM

                              I. CLIENT INFORMATION

CLIENT/PARTICIPANT FIDELITY BROKERAGE ACCOUNT NUMBER:
                                                      --------------------------

EFFECTIVE DATE OF THIS INSTRUCTION FORM: December 1, 2004

TERMINATION DATE OF THIS INSTRUCTION FORM (SEE SECTION A(5) FOR OTHER
TERMINATION EVENTS): January 3, 2006

CLIENT NAME: Margaret Seif                CLIENT SSN:
                                                      --------------------------
CLIENT ADDRESS:
                ----------------------------------------------------------------

CLIENT PHONE NO.:                          CLIENT FAX NO.:
                  ------------------------                 ---------------------

ISSUER NAME: RSA Security Inc.

CLASS AND PAR VALUE OF SECURITIES: Common Stock   STOCK SYMBOL: RSAS

AFFILIATE/"CONTROL PERSON" STATUS: (check applicable boxes)

[X] I am     [ ] I am not     an officer, director or 10% owner of Issuer

[X] I have   [ ] I have not   been notified that Issuer will file Form 4
                              statements on my behalf consistent with Issuer's
                              designation of me as a "Section 16 reporting
                              person"

[ ] I have   [X] I have not   been notified by Issuer that I may be deemed an
                              "affiliate," as defined in Rule 144 of the
                              Securities Act of 1933

                              II. SELLING SCHEDULE

        LONG SHARES HELD ON DEPOSIT WITH FIDELITY AND TO BE SOLD/DONATED

<TABLE>
<CAPTION>
                                                                               TIME IN                   DONOR
                                           EARLIEST POSSIBLE                    FORCE       LIMIT    NAME/FIDELITY
NUMBER OF  ORIGINAL PURCHASE   NATURE OF     SALE/DONATION    TYPE OF ORDER   (DAY/DATE     PRICE   BROKERAGE ACCT.
  SHARES         DATE         ACQUISITION       DATE(1)       (MARKET/LIMIT)  RANGE/GTC)  (IF ANY)    NO.(IF ANY)
---------  -----------------  -----------  -----------------  --------------  ----------  --------  ---------------
<S>        <C>                <C>          <C>                <C>             <C>         <C>       <C>





</TABLE>

               SHARES TO BE PURCHASED AND DEPOSITED WITH FIDELITY

<TABLE>
<CAPTION>
NUMBER OF    TYPE OF ORDER                   TIME IN FORCE                 LIMIT PRICE
  SHARES   (MARKET/LIMIT)(1)  (SPECIFY DAY/DATE RANGE/GOOD-TILL-CANCELED)    (IF ANY)
---------  -----------------  -------------------------------------------  -----------
<S>        <C>                <C>                                          <C>





</TABLE>

                         PURCHASE PLAN SHARES TO BE SOLD

----------
(1)  Where possible, orders will be traded on a "not held" basis. "Not Held"
     means an instruction on an order to buy or sell securities, indicating that
     the customer has given the floor broker time and price discretion in
     executing the best possible trade but will not communicate with the floor
     broker during such execution or hold the broker responsible if the best
     deal is not obtained. Client acknowledges that, for purposes of Rule
     10b5-1, such activities shall not be deemed to be the independent
     discretion of Broker concerning how, when or whether to effect trades in
     the Shares.

<PAGE>

<TABLE>
<CAPTION>
                                                                                                    TIME IN
DATE ON WHICH SHARES  NUMBER OF SHARES TO  NUMBER OF SHARES TO                                        FORCE     LIMIT
WILL BE DELIVERED TO      BE ACQUIRED       BE SOLD UNDER THIS  EARLIEST POSSIBLE  TYPE OF ORDER   (DAY/DATE    PRICE
       BROKER         UNDER PURCHASE PLAN      TRADING PLAN        SALE DATE(1)    (MARKET/LIMIT)  RANGE/GTC)  (IF ANY)
--------------------  -------------------  -------------------  -----------------  --------------  ----------  --------
<S>                   <C>                  <C>                  <C>                <C>             <C>         <C>





</TABLE>

                      STOCK OPTION SHARES TO BE SOLD (HELD)

<TABLE>
<CAPTION>
                                                                                                TIME IN
               OPTION    NUMBER OF    NUMBER OF     NUMBER OF      EARLIEST                       FORCE     LIMIT
OPTION GRANT  EXERCISE  OPTIONS TO  SHARES TO BE  SHARES TO BE  POSSIBLE SALE  TYPE OF ORDER   (DAY/DATE    PRICE
    DATE        PRICE    EXERCISE       SOLD          HELD         DATE(1)     (MARKET/LIMIT)  RANGE/GTC)  (IF ANY)
------------  --------  ----------  ------------  ------------  -------------  --------------  ----------  --------
<S>           <C>       <C>         <C>           <C>           <C>            <C>             <C>         <C>
                                         See attached Schedule A





</TABLE>

On any day when Broker must exercise Options in order to cover a shortfall in
the Client Account, Broker should:

[X]  exercise first those vested Options with the earliest expiration date.

[ ]  exercise first those vested Options with the lowest strike price.

[ ]  other (insert other direction)
                                    --------------------------------------------

                            EQUITY SWAP ARRANGEMENTS

<TABLE>
<CAPTION>
                                                                                                        INVESTMENT
                                                  PAYMENT                                                RETURN TO
                                                 TERMS FOR                                             WHICH CLIENT
                                   NUMBER OF      COMPANY    DELIVER COMPANY SHARES                       BECOMES
EFFECTIVE DATE                  COMPANY SHARES   SHARES ON   OUT OF CLIENT ACCOUNT?                     ENTITLED ON
      OF           NAME OF    SUBJECT TO EQUITY  EFFECTIVE  (IF SO, SPECIFY DELIVERY  SETTLEMENT DATE   SETTLEMENT   COMMENTS
 TRANSACTION    COUNTERPARTY        SWAP           DATE           REQUIREMENTS)        OF TRANSACTION      DATE      (IF ANY)
--------------  ------------  -----------------  ---------  ------------------------  ---------------  ------------  --------
<S>             <C>           <C>                <C>        <C>                       <C>              <C>           <C>





</TABLE>

----------
(1)  Where possible, orders will be traded on a "not held" basis. "Not Held"
     means an instruction on an order to buy or sell securities, indicating that
     the customer has given the floor broker time and price discretion in
     executing the best possible trade but will not communicate with the floor
     broker during such execution or hold the broker responsible if the best
     deal is not obtained. Client acknowledges that, for purposes of Rule
     10b5-1, such activities shall not be deemed to be the independent
     discretion of Broker concerning how, when or whether to effect trades in
     the Shares.


                                                                          2 of 6

         BROKERAGE SERVICES PROVIDED BY FIDELITY BROKERAGE SERVICES LLC.
                               MEMBER NYSE, SIPC.

    ACCOUNTS CARRIED BY NATIONAL FINANCIAL SERVICES LLC. MEMBER NYSE, SIPC.

<PAGE>

                              III. ADDITIONAL TERMS

-    If Broker cannot effect any trade of Shares for any of the reasons
     described in Section B(14) of the Terms and Conditions of this Trading
     Plan, then Broker should: (check no more than one of the following)

     [X]  execute the trade on the next possible business day

          (NOTE: please understand that if you check this box you are changing
          your day-only limit orders to limit orders for a significant or
          unspecified duration - if this is not what you want, you should check
          the THIRD box instead).

     [ ]  cancel the trade and add the unfilled trade to the next trade located
          on the same trading grid of this Instruction Form

          (NOTE: please be realistic about whether the market will accommodate
          your volumes on later sale dates if too many rollovers occur under
          this option. If you have a concern that Shares may be left unsold at
          the end of your trading plan, you may wish to seriously consider
          checking the THIRD box instead.).

     [ ]  cancel the trade altogether and proceed only with the remaining trades
          on this Instruction Form.

Please be advised that, notwithstanding your choice above, the THIRD action will
be imposed uniformly in the event that a Trading Plan is unilaterally suspended
by the Issuer and we deem the suspension to be permissible. See Section A(5) of
the Trading Plan in this regard.

-    Share amounts listed shall be increased or decreased to reflect stock
     splits or other similar changes or corporate actions in Issuer's
     capitalization that may occur prior to execution of the trades.

-    Limit price orders are at the limit price or better, beginning at the
     opening of regular market trading hours on the specified trade date(s) and
     expiring at the close of regular market trading hours on the trading
     date(s).

-    The instructions contained herein are subject in all respects to the terms
     and conditions of the Trading Plan to which this Instruction Form is
     attached.

-    Once completed, please fax this completed 10b5-1 Trading Plan to
     603-864-2040 and overnight mail it to 200 LIBERTY STREET, NY5M, NEW YORK,
     NEW YORK 10281 ATTN: RESTRICTED STOCK SERVICES.

                                 IV. SIGNATURES

Client agrees to all of the terms and conditions set forth on this Instruction
Form, as may be amended from time to time, the attached 10b5-1 Terms and
Conditions, and all applicable exhibits hereto (collectively, the "AGREEMENT"),
INCLUDING BUT NOT LIMITED TO A PRE-DISPUTE ARBITRATION CLAUSE CONTAINED IN
SECTION 18 OF THE CUSTOMER AGREEMENT.

CLIENT                                  ACKNOWLEDGED BY: RSA SECURITY INC.
                                                            Enter Name of Issuer


By: /s/ Margaret K. Seif                By: /s/ Jeffrey D. Glidden
    ---------------------------------       ------------------------------------
Name: Margaret K. Seif                  Name: Jeffrey D. Glidden
Title: Senior VP and General Counsel    Title: Senior VP & CFO

Date: 11/2/04                           Date: 11/3/04


ACCEPTED BY FIDELITY BROKERAGE
SERVICES LLC


By: /s/ Matthew Nash
    ---------------------------------
Name: MATTHEW NASH
Title: SENIOR VICE PRESIDENT

Date: DECEMBER 20, 2004


                                                                          3 of 6

         BROKERAGE SERVICES PROVIDED BY FIDELITY BROKERAGE SERVICES LLC.
     MEMBER NYSE, SIPC. ACCOUNTS CARRIED BY NATIONAL FINANCIAL SERVICES LLC.
                               MEMBER NYSE, SIPC.

<PAGE>

                   10B5-1 TRADING PLAN - TERMS AND CONDITIONS

     THIS TRADING PLAN is adopted by Client and Fidelity Brokerage Services LLC,
a Delaware limited liability company ("Broker"), in compliance with Rule
10b5-1(c)(1) under the Securities Exchange Act of 1934, as amended (the
"Exchange Act").

     WHEREAS, Client wishes to provide instructions to Broker as to how, when
and whether to conduct purchases or sales (and/or donations to charitable
institutions in contemplation of sales by such institutions) of securities of
the Issuer in compliance with Rule 10b5-1 under the Exchange Act as set forth in
the foregoing Instruction Form (the "Shares"); and

     WHEREAS, the Shares may include Shares that Client has or will have the
right to acquire under outstanding employee stock options of the Issuer
("Options") and/or Shares ("Benefit Plan Shares") issued or to be issued to
Client based upon Client's participation in one or more of Issuer's employment
compensation plans, which is either listed on Schedule A to the Issuer's
Recordkeeping and Administrative Services Agreement entered into with Fidelity
Stock Plan Services, LLC ("SPS"), in the event that the Issuer is an SPS client
(an "SPS Customer") and such plan(s) are serviced by SPS as the plan sponsor, or
in any other case which plan is attached hereto as Exhibit 1 (collectively in
either case, the "Employee Benefit Plan"); and

     WHEREAS, Client has read and signed the customer agreement (the "Customer
Agreement") governing the client's account; and

     WHEREAS, Issuer has acknowledged that this Trading Plan is consistent with
Issuer's insider trading policies as such are in effect as of the date hereof,
and Broker has agreed to accept the instructions under this Trading Plan.

     NOW, THEREFORE, in consideration of the foregoing and the respective
covenants and agreements hereinafter contained, the parties hereby agree as
follows:

A. IMPLEMENTATION OF TRADING PLAN.

1. Client hereby instructs Broker to conduct purchases, sales or donations of
the Shares and, if applicable, exercise of the Options in accordance with the
attached Instruction Form, which Instruction Form forms a part of and is subject
to these Terms and Conditions.

2. If any trading date specified on the Instruction Form is a day on which
brokers or dealers are authorized or obligated by law, regulation or executive
order to close in New York, New York (an "Exempt Day"), such date will be
construed to mean the next calendar day which is not an Exempt Day.

3. At least sixty (60) calendar days must lapse between the effective date of
this Trading Plan and the earliest trading date set forth on the Instruction
Form. Client understands and acknowledges that all proposed trades under this
Trading Plan are subject to Broker's completion of customary due diligence, and
that many of these procedures are dependant upon the timely cooperation of
Client and Issuer; Broker will not be responsible for any losses or damages
(including but not limited to lost opportunity) resulting from any delays in
trading caused, in whole or in part, by Broker's unsuccessful good faith efforts
to complete customary due diligence concerning any aspect of this Trading Plan.
Client acknowledges that Broker has informed Client of, and Client understands
and has put Issuer on notice concerning, what "customary due diligence" means in
the context of this Trading Plan and the proposed trades hereunder.

4. In consideration of Broker's acceptance of the instructions under this
Trading Plan, Client acknowledges that the Customer Agreement shall control in
the event of any inconsistencies between the Customer Agreement and this Trading
Plan. Client also understands that the Client Account is carried by National
Financial Services LLC, an affiliate of Broker.

5. This Trading Plan is effective as of the execution date of the Instruction
Form and terminates upon the earlier of (i) the Termination Date set forth in
Item I of the Instruction Form; (ii) the completion of all trades under this
Trading Plan; (iii) the termination of the Client Account in accordance with the
Customer Agreement; (iv) the termination of this Trading Plan in conformity with
Section E(5) hereof; (v) the first available date that does not fall within a
quarterly or special blackout of Issuer after which Broker has received notice
from Client of the liquidation, dissolution, bankruptcy or insolvency of Client
or the termination of Client's employment with Issuer or (vi) the death of
Client. Notwithstanding the foregoing, Broker shall suspend trading under this
Trading Plan, in whole or in part as appropriate, upon notification by Issuer's
General Counsel's Office that the Issuer has imposed in good faith an imposition
of trading restrictions on the Client (an "Issuer Restriction"), provided that
Issuer's General Counsel's Office has provided Broker with at least two (2)
business days prior written notice, signed by Issuer's General Counsel Office
and delivered in accordance with Section E(6) hereof, of such Issuer Restriction
(a "Trading Suspension Notice") Any such trading suspension shall be lifted at
the time stated in the Trading Suspension Notice or otherwise when Broker is
notified in writing by Issuer's General Counsel's Office that such Issuer
Restrictions have terminated (a "Trading Suspension Release"). Broker shall
resume effecting trades in accordance with this Trading Plan as soon as
practicable after delivery of the Trading Suspension Release. Any unexecuted
trades that would have been executed in accordance with the terms of Appendix A
but for the Trading Suspension Notice shall be deemed to be cancelled and shall
not be executed pursuant to this Trading Plan.

6. Client agrees to deliver promptly Shares now or hereafter coming into
Client's possession that are subject to sale or donation under this Trading
Plan, including, if applicable, Benefit Plan Shares, for so long as sales or
donations are to be conducted under this Trading Plan, all of which Shares shall
be deposited into the Client Account in the name of and for the benefit of
Broker. Broker shall withdraw Shares from the Client Account in order to effect
sales or donations of Shares under this Trading Plan. Broker agrees to notify
Client promptly if at any time during the term of this Trading Plan the number
of Shares in the Client Account is less than the number of Shares remaining to
be sold pursuant to this Trading Plan, unless such shortfall will be eliminated
in the ordinary course by the exercise of Options in accordance with this
Trading Plan. To the extent that any Shares remain in the Client Account upon
termination of this Trading Plan, Broker agrees to return such Shares promptly
to Issuer's transfer agent for re-legending to the extent that such Shares would
then be subject to transfer restrictions in the hands of Client.

7. (a) If this Trading Plan covers exercises of Options, then Client agrees to
make appropriate arrangements with Issuer and its transfer agent and Employee
Benefit Plan administrator to permit Broker to furnish notice to Issuer of the
exercise of the Options and to have underlying Shares delivered to Broker as
necessary to effect sales or donations under this Trading Plan. Shares received
upon exercise of Options shall be delivered to the Client Account. In this
regard:

     (i) In the event Issuer is not an SPS Customer, Client agrees to complete,
execute and deliver to Broker from time to time Broker's customary forms of
Employee Stock Option Notice of Intent and Agreement for the exercise of Options
pursuant to this Trading Plan, at such times and in such numbers as Broker shall
request;

     (ii) Client hereby authorizes: (1) Broker to serve as Client's agent and
attorney-in-fact to cause said Shares to be issued upon payment (or eligible
margin credit, if applicable) of the Option exercise price and, in the event
Issuer is not an SPS Customer, receipt from Client of the properly endorsed
Employee Stock Option Notice of Intent and Agreement and (2) Broker, Issuer
and/or Issuer's stock plan administrator to exchange information regarding the
acquisition and disposition of said Shares, including, without limitation,
notification of the sale or donation of Shares acquired as the result of
exercise of a stock option and verification by Issuer of tax withholding;

     (iii) On each day that sales or donations are to be made under this Trading
Plan (or, in the event that Client owns a portion of Shares directly and not
pursuant to Options, on any day that the number of Shares in the Client Account
is less than the number of Shares to be sold on such day), Broker shall exercise
a sufficient number of Options to effect such sales or donations in the manner
specified on the Instruction Form. Broker shall in no event exercise any Option
if at the time of exercise the exercise price of the Option is equal to or
higher than the market price of the Shares; and

     (iv) Broker shall, in connection with the exercise of Options, remit to
Issuer the exercise price thereof, which amount shall be deducted from the
proceeds of sale of the Shares together, if applicable, with any margin credit
interest then accrued in favor of Broker, which interest Broker shall compute in
accordance with its customary practices.

(b) If this Trading Plan covers:

     (i) Benefit Plan Shares, then Client shall provide written notice to Broker
at any time when Issuer amends or terminates the related Employee Benefit Plan,
together with a written copy of any such amendment(s), as soon as practicable
but in any event no later than two (2) business days after Client receives
notice thereof from Issuer. If Client changes or terminates any contribution
elections during a contribution election period where Client is instructing
Broker on Appendix A to sell all or a percentage of the Purchase Plan Shares
that Client expects to receive pursuant to such contribution election, as
opposed to specifying on Appendix A an actual number of shares that Broker
should sell, Client shall provide written notice to Broker of such contribution
election change or termination as soon as practicable but in any event no later
than two (2) business days after Client effects any such change, which written
notice must be accompanied by Client's representation that (a) Client was not in
possession of any material nonpublic information concerning Issuer or its
securities when Client effected such change and (b) such change was made in good
faith and not as a part of a plan or scheme to evade compliance with the federal
securities laws; and/or

     (ii) equity swap arrangements involving Shares, then Client shall provide
written notice to Broker at any time when Client changes the terms of such
equity swap arrangement after the effective date thereof, together with a
written copy of any such change(s), as soon as practicable but in any event no
later than two (2) business days after Client effects such change, which written
notice must be accompanied by Client's representation that (a) Client was not in
possession of any material nonpublic information concerning Issuer or its
securities when Client effected such change and (b) such change was made in good
faith and not as a part of a plan or scheme to evade compliance with the federal
securities laws.

B. REPRESENTATIONS, WARRANTIES AND COVENANTS OF CLIENT.

Client makes the following representations, warranties and covenants to Broker:

1. Client has all requisite power and authority to adopt this Trading Plan and
to carry out its obligations hereunder. The execution and delivery of this
Trading Plan and the performance of the obligations of Client hereunder have
been duly authorized and approved by all necessary action on the part of Client,
and no other proceedings on the part of Client are necessary to authorize and
approve this Trading Plan and the transactions contemplated hereby. This Trading
Plan has been duly executed by Client and constitutes its valid and binding
obligation, enforceable against it in accordance with its terms.


                                                                          4 of 6

         BROKERAGE SERVICES PROVIDED BY FIDELITY BROKERAGE SERVICES LLC.
                               MEMBER NYSE, SIPC.
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<PAGE>

2. The execution, delivery and performance by Client of this Trading Plan does
not, directly or indirectly (with or without notice or lapse of time),
contravene, conflict with, or result in a violation of any of the terms or
requirements of any legal or contractual requirement or order to which Client
may be subject, nor does this Trading Plan require any consent, waiver,
authorization or approval of any person or entity other than Client, Issuer and
Broker. Client shall immediately notify Broker if Client becomes subject to a
legal, regulatory or contractual restriction or undertaking that would prevent
Broker from carrying out its obligations under this Trading Plan.

3. If this Trading Plan covers:

     (i) Benefit Plan Shares, then during the term of this Trading Plan, Client
shall comply with the terms of the Employee Benefit Plan and, for any
contribution election period during the term of this Trading Plan that Client
has instructed Broker on Appendix A to sell all or a percentage of the Purchase
Plan Shares that Client expects to receive based upon a contribution election,
rather than specifying on Appendix A the actual number of shares Broker should
sell, Client shall not (x) directly or indirectly cause the Employee Benefit
Plan to be amended or terminated, (y) amend or terminate such contribution
elections under the Employee Benefit Plan, or (z) otherwise take any direct or
indirect action having an impact upon the number of Benefit Plan Shares
committed to be purchased by Client under the Employee Benefit Plan, at any time
with respect to clauses (x), (y) and (z) when Client has material nonpublic
information concerning Issuer or its securities and/or as a part of a plan or
scheme to evade compliance with this Trading Plan or the federal securities
laws; and/or

     (ii) equity swap arrangements involving Shares, then during the term of
this Trading Plan, Client shall comply with the terms of such equity swap
arrangements and shall not (x) directly or indirectly cause the equity swap
arrangement to be amended or terminated, (y) amend or terminate such equity swap
arrangement, or (z) otherwise take any direct or indirect action having an
impact upon the number of Shares committed under such equity swap arrangement,
at any time with respect to clauses (x), (y) and (z) when Client has material
nonpublic information concerning Issuer or its securities and/or as a part of a
plan or scheme to evade compliance with this Trading Plan or the federal
securities laws.

4. The execution date of this Trading Plan does not fall within any quarterly or
special blackout period of Issuer.

5. In the event that this Trading Plan covers sales or donations of Shares,
Client has, or when Shares to be sold or donated under this Trading Plan are
issued and delivered to Broker, will then have, valid and marketable title to
the Shares, free and clear of any liens, claims, charges, security interests or
other legal or equitable encumbrances, limitations or restrictions, other than
pursuant to (a) this Trading Plan, (b) compliance by Client with the exercise
provisions of the Options, if this Trading Plan covers Options, (c) compliance
by Client with the terms of the Employee Benefit Plan, if this Trading Plan
covers Purchase Plan Sales and (d) compliance by Client with the terms of equity
swap arrangements covering Shares, if this Trading Plan covers Shares subject to
equity swap arrangements.

6. As of the execution date hereof, Client is not aware of any material
nonpublic information concerning Issuer or its securities. Client is entering
into this Trading Plan in good faith and not as a part of a plan or scheme to
evade compliance with the federal securities laws. Client is currently permitted
to trade in Shares in accordance with Issuer's insider trading policies and has
obtained the approval or acknowledgement of Issuer's counsel to enter into this
Trading Plan.

7. Within five (5) days of the execution date of this Trading Plan, Client shall
file a copy of this Trading Plan with the General Counsel of Issuer.

8. If the shares are "restricted securities" and/or Client may be deemed an
"affiliate" of Issuer, as such terms are defined in Rule 144, then within five
(5) days of the first date on which sales, if any, can be made under this
Trading Plan, and within five (5) days of each three-month anniversary of such
first date (providing that on such anniversary any sales of Shares remain
pending under this Trading Plan), Client shall execute and deliver to Broker a
certification disclosing trades made by Client and its related parties within
the three months preceding such first date or three-month anniversary date, as
the case may be, for purposes of determining compliance of sales to be made
under this Trading Plan with Rule 144 under the Securities Act of 1933, as
amended.

9. If Client is an institution, Client has implemented reasonable policies and
procedures to ensure that the individuals authorized to enter into this Trading
Plan on its behalf are not aware, as of the date hereof, of any material
nonpublic information concerning Issuer or its securities and, to the knowledge
of Client, no such individual is aware of any such information.

10. Client agrees that Client shall not, directly or indirectly, communicate any
material nonpublic information relating to the Issuer or its securities to any
employee of Broker or its affiliates.

11. Client will not enter into any new, or change any existing, corresponding or
hedging transaction or position with respect to the Shares for so long as this
Trading Plan is in effect.

12. Client agrees to (i) comply with all applicable laws in connection with the
performance of this Trading Plan, including, without limitation, Sections 13 and
16 of the Exchange Act and the respective rules and regulations promulgated
thereunder; and Rule 144, and (ii) make all filings, if any, required under Rule
144 and Sections 13(d), 13(g) and 16 of the Exchange Act in a timely manner, to
the extent any such filings are applicable to Client, and to indicate on any
such filing, by means of an appropriate footnote or footnotes, as the case may
be, that the applicable transactions were effected under a contract, plan or
instruction in accordance with Rule 10b5-1 under the Exchange Act.

13. Client agrees not to take, and agrees to cause any related party (including
any person or entity with which Client would be required to aggregate sales of
Shares pursuant to paragraph (a)(2) or (e) of Rule 144) not to take, any action
that would cause this Trading Plan not to comply with Rule 144, or Section 16 of
the Exchange Act, including, without limitation, any action that would (i)
violate Rule 144 volume limitations or (ii) trigger Section 16 short-swing
liability.

14. Client understands that Broker may not be able to effect a transaction under
this Trading Plan due to (i) any of the extraordinary events set forth in
Sections 15 or 16 of the Customer Agreement, as the case may be; (ii) any of the
events described in Sections A(3) of this Trading Plan; (iii) a legal,
regulatory or contractual restriction or suspension applicable to Client,
Client's affiliates, Broker or Broker's affiliates (including the volume
limitations of Rule 144); (iv) failure of Broker to receive Shares, including
Benefit Plan Shares or Shares subject to equity swap arrangements, or delay in
Broker's receipt of such shares for deposit into Client's account, if
applicable, whether or not such failure or delay is consistent with the terms of
the Employee Benefit Plan, equity swap or any other agreement to which Broker is
not a controlling party; (v) if this Trading Plan covers Options, and on
Instruction Form Client places a market order with respect to Shares subject to
Options, failure of the market price for such Shares to exceed the exercise
price of such Options on the exercise date or (vi) a suspension, expiration,
termination or unavailability of any applicable registration statement related
to Issuer. If Broker cannot effect any trade in Shares for any of the reasons
described herein, then Broker shall follow Client's instructions set forth on
the Instruction Form with respect to such trade(s). Client agrees that Broker
shall be entitled to rely on a Trading Suspension Notice or a Trading Suspension
Release (each as defined in Section A(5) above) as either may impact trading
under this Trading Plan, so long as such notice or release is on letterhead of
the Issuer and signed by a person representing himself or herself as the General
Counsel or an authorized representative of the General Counsel of Issuer, and
Broker acts in good faith, after reasonable inquiry when the need therefore is
indicated by the circumstances, and without knowledge that would cause such
reliance to be unwarranted.

15. Client has consulted with his or her own advisers as to the legal, tax,
business, financial and related aspects of, and has not relied on Broker or any
person affiliated with Broker in connection with Client's adoption and
implementation of, this Trading Plan.

16. Client has signed the Customer Agreement, including the margin account
agreement and disclosure of potential for stock buy-ins.

17. If this Trading Plan covers Options, then Client further represents and
warrants the following to Broker (as of the effective date and as of the date of
exercise of the Options):

(a) The Options were granted in connection with Client's employment or
directorship, Client is authorized to exercise them, and Client has received
from Issuer a prospectus covering the sale of the Shares subject to Options.

(b) Client understands that the exercises of the Options and the subsequent
sales of the Shares subject to Options may have significant tax consequences.
Client further understands that Broker and its employees are not authorized to
give Client tax or investment advice, and has consulted other sources Client
deems appropriate in connection with Client's transactions.

(c) Client agrees that Broker will not exercise any independent discretion in
determining how, when or whether to exercise the Options other than in the
ordinary course of business in accordance with the instructions set forth in
this Trading Plan.

(d) Client agrees to be liable for any dividends, stock splits and/or spin-offs
that may take place between the date of sale of Shares subject to Options and
the issuance date of such Shares.

(e) Client understands that if there is an extension of credit by Broker for
Option exercises and payment of any required withholding for taxes and
certificate issuance fees will result in a debit balance in the Client Account,
that Broker shall charge interest on all credit extended to Client, and that all
transactions in the Client Account will be subject to the provisions of the
Customer Agreement.

18. If this Trading Plan covers Benefit Plan Shares, then Client further
represents and warrants the following to Broker (as of the effective date and as
of the date of purchase of the Benefit Plan Shares):

(a) The Benefit Plan Shares are granted in connection with Client's employment
or directorship, Client is authorized to purchase them, and Client has received
from Issuer a prospectus covering the sale of the Benefit Plan Shares to Client.

(b) Client understands that trades in Benefit Plan Shares under this Trading
Plan may have significant tax consequences. Client further understands that
Broker and its employees are not authorized to give Client tax or investment
advice, and has consulted other sources Client deems appropriate in connection
with Client's transactions.

(c) Client agrees that Broker will not exercise any independent discretion in
determining how, whether or when to purchase Benefit Plan Shares.

C. LEGAL COMPLIANCE; AGENT DUTIES.

1. It is the intent of the parties that this Trading Plan satisfy the
affirmative defense conditions of Rule 10b5-1(c) and comply with the
requirements of Rule 10b5-1, including, without limitation, the requirement
under Rule 10b5-1(c) that Client not be


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<PAGE>

permitted to exercise any influence subsequent to the effective date of this
Trading Plan over how, when or whether to effect trades in the Shares.

2. Client agrees that Broker, in performing its duties under this Trading Plan,
is acting solely as agent for Client and shall not by reason thereof assume any
fiduciary or advisory relationship with Client rightly borne by Issuer. Nothing
in this Trading Plan shall be construed as to impose upon Broker any further
obligation to exercise discretion over how, when or whether to effect trades in
the Shares. If Client and Issuer are the same or affiliated entities entering
into this Trading Plan as part of a share repurchase program, then such parties
acknowledge that Broker shall endeavor to structure all repurchases in Shares
under this Trading Plan in accordance with Rule 10b-18 under the Exchange Act,
and that for purposes of Rule 10b5-1 such activities shall not be deemed to be
the independent discretion of Broker concerning how, when or whether to effect
trades in the Shares.

3. Client is the sole obligor with respect to any taxes due upon any sale of
Shares and upon the exercise of Options under this Trading Plan, as the case may
be, and Broker shall have no obligation with respect to such taxes; furthermore,
Broker shall not be required to withhold any such taxes from the proceeds of any
sale of Shares under this Trading Plan to be delivered to Client.

4. In respect of any sales of Shares under this Trading Plan, if such Shares are
"restricted securities" and/or Client may be deemed an "affiliate" of Issuer, as
such terms are defined in Rule 144, then Broker will complete on behalf of
Client and file with the appropriate authorities the required Forms 144 of
Client, provided that Client has complied with its covenant set forth in Section
B(8) above with respect to each such filing. Client understands and agrees that
such Forms 144 shall provide (i) that the sales are being made pursuant to a
Rule 10b5-1 Trading Plan, (ii) the date on which such Trading Plan was adopted
and (iii) that Client's knowledge speaks as of the date such Trading Plan was
adopted. Client shall cooperate with Broker to execute and file any
modifications to an effective Form 144 in order to comply with the foregoing
sentence.

5. (a) If Client indicates on Instruction Form that Issuer will file Form 4
statements on Client's behalf consistent with Issuer's designation of Client as
a "Section 16 reporting person," then Broker will endeavor to transmit to
Issuer, in writing, the details of any trade executed under this Trading Plan
within one business day of the trade execution (in each case, a "Broker Trade
Notification").

(b) Client acknowledges that under certain circumstances Broker may need to
amend a Broker Trade Notification due to changes to information that are not
evident until the settlement date of the transaction that was subject to such
notification -- for example, changes to purchase or sale prices triggered by
challenge-based trade corrections. Broker agrees to endeavor to notify Issuer of
any such changes within a reasonable amount of time by transmitting an amended
Broker Trade Notification to Issuer. Client acknowledges that such amended
notifications will reach Issuer after the passing of the two-business day Form 4
filing deadline imposed by Section 16(a) of the Exchange Act. Client agrees that
in the event Broker transmits such an amended Broker Trade Notification to
Issuer, Client will work directly with Issuer to determine whether Client will
then be required, based upon the changes disclosed in said amended Broker Trade
Notification, to amend any of Client's Section 16 statements or other public
disclosure Client previously made regarding the transaction that was the subject
of the original Broker Trade Notification.

(c) Client acknowledges that Broker is performing the services that are the
subject of this Section C(5) solely as a customer service and an accommodation
to Client and acknowledges further that Broker will not be liable for any claim,
loss, damage or expense (including, but not limited to attorneys' fees) arising
out of failure by Broker to provide any of said services.

6. If Client and Issuer are the same or affiliated entities entering into this
Trading Plan as part of a share repurchase program, such parties acknowledge
that Broker will structure its purchases of Shares in accordance with Rule
10b-18 under the Exchange Act, and that such structuring shall not be construed
to be additional discretion on the part of the Broker.

D. INDEMNIFICATION; LIMITATION OF LIABILITY.

Client agrees to indemnify and hold harmless Broker, its affiliates and their
respective directors, officers and employees from and against all claims,
losses, damages, costs and liabilities (including, without limitation, any legal
or other expenses incurred in connection with defending or investigating any
such action or claim) (collectively, "Losses") arising out of or attributable to
this Trading Plan, including, without limitation, any inaccuracy of any
representation, warranty, statement of agreement or understanding made by Client
herein, any breach by Client of this Trading Plan or any violation by Client of
applicable laws or regulations, except to the extent that any such Losses arise
out of acts of gross negligence, bad faith or willful misconduct on the part of
Broker or any of its affiliates in performing their obligations hereunder.
Client will reimburse Broker for any and all fees, costs and expenses of any
kind reasonably incurred by Broker as a result of any such Losses. This
indemnification shall survive termination of this Trading Plan.

E. GENERAL PROVISIONS.

1. Each party shall, upon the request of the other, execute, acknowledge and
deliver to the other any information, document or instrument that may be
required to accomplish the intent of this Trading Plan. Each party agrees to
cooperate to effectuate the intent of this Trading Plan and shall take all
appropriate action necessary or useful in doing so.

2. This Trading Plan shall be construed, performed and enforced in accordance
with, and governed by, the laws of the State of New York, without giving effect
to the principles of conflicts of laws thereof. The parties hereto irrevocably
consent to the jurisdiction of the courts of the County of New York, State of
New York or the United States of America for the Southern District of New York
and elect such court or courts as the sole judicial forum for the adjudication
of any matters arising under or in connection with this Trading Plan.

3. In the event that any provision of this Trading Plan is declared by any court
or other judicial or administrative body to be null, void or unenforceable, said
provision shall survive to the extent it is not so declared, and all of the
other provisions of this Trading Plan shall remain in full force and effect.

4. Any amendment of this Trading Plan shall: (a) be in writing and signed and
dated by Client and Broker; (b) be filed with Issuer's General Counsel or Chief
Legal Officer within five (5) business days after the effective date of such
amendment; (c) not be made during any quarterly blackout period or any special
blackout period of Issuer; (d) be accompanied by Client's representation that
(i) Client was not in possession of any material nonpublic information
concerning Issuer or its securities when Client modified this Trading Plan and
(ii) this Trading Plan is being modified in good faith and not as a part of a
plan or scheme to evade compliance with the federal securities laws; and (e) not
become effective until the later of (1) 30 calendar days after it is signed by
Client and Broker and (2) the completion of Broker's customary due diligence in
respect of the amendment (in this regard, Client reaffirms his/her
understandings in Section A(3) regarding the meaning of "customary due
diligence"). There may be no more than one amendment under this Section E(4)
during any fiscal quarter of Issuer.

5. Any termination of this Trading Plan by Client must be: (i) in writing and
signed and dated by Client and Broker; and (ii) filed with Issuer's General
Counsel or Chief Legal Officer within five (5) business days after the effective
date of such termination.

6. All notices, requests, demands and other communications under this Trading
Plan shall be in writing and shall be deemed to have been duly given: (i) on the
date of service if served personally on the party to whom notice is to be given;
(ii) on the date when receipt by addressee is confirmed in writing, if sent via
facsimile transmission to the facsimile number given below; or (iii) on the
first business day with respect to which a reputable air courier guarantees
delivery; to the party as follows:

<TABLE>
<S>           <C>
If to Client: See Instruction Form

If to Broker: Fidelity Brokerage Services LLC
              c/o National Financial Services LLC
              200 Liberty Street, NY5M
              New York, NY 10281
              Attention: Restricted Stock Services, 10b51
              Fax: (603) 864-2040

Copy to:      FMR Corp. Legal Department
              200 Liberty Street, NY5M
              New York, NY  10281
              Attention: Brian A. Williams, Esq.
              Fax: (617) 385-2940

If to Issuer: RSA Security Inc.
              174 Middlesex Turnpike
              Bedford, MA 01730
              Attention: General Counsel
              Fax: (781) 515-5450
</TABLE>

Any party may change its address for the purpose of this Section E(6) by giving
the other parties written notice of its new address in the manner set forth
above.

7. This Trading Plan, together with the Instruction Form and any exhibits hereto
or thereto, contains the entire understanding between the parties with respect
to the transactions contemplated hereby and supersedes and replaces all prior
and contemporaneous agreements and understandings, oral or written, with regard
to such transactions.

8. This Trading Plan may be executed in one or more counterparts, each of which
shall be deemed an original and all of which shall constitute a single document.

                 ~ REMAINDER OF PAGE INTENTIONALLY LEFT BLANK ~


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         BROKERAGE SERVICES PROVIDED BY FIDELITY BROKERAGE SERVICES LLC.
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<PAGE>

                                   SCHEDULE A
                                 (Stock Options)
                         TO MARGARET K. SEIF 10B5-1 PLAN
                             DATED NOVEMBER 4, 2004

Name of Seller: Margaret Seif Seller's Social Security #
                                                         -----------------------
Daytime Tel. #:            Cellular:            Fax #:            Email:
                ----------           ----------        ----------

--------------------------

     Exercise of Options and Sale of Stock Obtained Upon Exercise of Options.

<TABLE>
<CAPTION>
            a.           b.            c.             d.               e.                   f.                 g.
                                                    Vesting      Designated Sale                        Net Limit Price
                                                   Date For           Period                            ($) or "Market"
                        Opton                      Unvested     -----------------   Authorized Number    Price (select
LINE    Grant ID #   Grant Date   Strike Price      Shares        From       To      of Option Shares        one):
-----   ----------   ----------   ------------   ------------   -------   -------   -----------------   ---------------
<S>     <C>          <C>          <C>            <C>            <C>       <C>       <C>                 <C>
   1    R98-1488       6/18/02        4.42       12/18/04       1/04/05   1/03/06          2,092             $14.42
        (NQ)                                     (130)
   2    R98-1488A      6/18/02        4.42       12/18/04       1/04/05   1/03/06         42,907             $14.42
        (NQ)                                     (2681)
   3    R98-313A       6/18/02        4.42       12/18/04       1/04/05   1/03/06         16,873             $14.42
        (NQ)                                     (1054)
   4    R94-1025       6/18/02        4.42       3/18/05        1/04/05   1/03/06          6,703             $14.42
        (NQ)                                     (419)
   5    R94-1025A      6/18/02        4.42       12/18/04       1/04/05   1/03/06         51,196             $14.42
        (NQ)                                     (3,199)
   6    94-1029        7/10/02        4.04       1/10/05        1/04/05   1/03/06         93,006             $14.04
        (ISO)                                    (6,250)
   7    94-1029A       7/10/02        4.04       10/10/05       1/04/05   1/03/06          6,994             $14.04
        (NQ)                                     (245)
   8    R94-557        8/12/98        8.04       Fully vested   1/04/05   1/03/06         16,581             $12.04
        (ISO)
   9    R94-902        8/12/98        8.04       Fully vested   1/04/05   1/03/06         75,000             $12.04
        (NQ)
  10    R94-557A       8/12/98        8.04       Fully vested   1/04/05   1/03/06         58,419             $12.04
  11    94-1038        11/18/03       13.12      2/18/06        1/04/05   1/03/06         17,090             $18.12
                                                 (1,848)
  12    94-1038A       11/18/03       13.12      11/18/04       1/04/05   1/03/06        132,910             $18.12
                                                 (30,000)

                                                   Total: 195,826
</TABLE>

Instructions:

1.   In columns (a) and (b), list the Options which are to be exercised.

<PAGE>

ADVANCED INSTRUCTION TO SELL COMMON STOCK

     I hereby instruct Fidelity Investments (referred to herein as "Fidelity")
for the period commencing January 4, 2005 and terminating on January 3, 2006 as
follows:

     In any given quarter, sales of stock should occur only in the period: (a)
commencing on the first day of the middle month of that quarter; provided that
the Company has publicly released its earnings for the prior quarter at least 48
hours earlier, and (b) terminating on the first day of the Company's trading
blackout period for the quarter.

     i)   With respect to any stock options with an exercise price equal to
          $4.42 per share, only exercise and simultaneously sell 5,000 vested
          options per quarter if the Company's Common Stock is trading at a
          price equal to $14.42 per share or higher.

     ii)  With respect to any stock options with an exercise price equal to
          $4.04 per share, only exercise and simultaneously sell 5,000 vested
          options per quarter if the Company's Common Stock is trading at a
          price equal to $14.04 per share or higher.

     iii) With respect to any stock options with an exercise price equal to
          $8.04 per share, only exercise and simultaneously sell 6,000 vested
          options per quarter if the Company's Common Stock is trading at a
          price equal to $12.04 per share or higher.

     iv)  With respect to any stock options with an exercise price equal to
          $13.12 per share, only exercise and simultaneously sell 10,000 vested
          options per quarter if the Company's Common Stock is trading at a
          price equal to $18.12 per share or higher.