<PAGE>
                                                                    Exhibit 99.7

MEMORANDUM

To:     Mark McHugh, Deutsche Bank Alex. Brown

Cc:     Marnie Seif


From:   Charles R. Stuckey Jr.                     /s/ Charles R. Stuckey, Jr.
                                                   -----------------------------

Date:   December 1, 2004

Re:     Advanced instructions to Exercise and Sell RSAS Options, Under Rule 144

Mark:

The instructions outlined in this memo are to be used as my 10B5-1 Plan for RSA
Security, Inc.:

A.   DURATION OF PLAN

     This plan should commence on February 1, 2005 and end June 30, 2005.

     This plan will be automatically extended for the entire calendar year 2005,
     if I am unable to institute another 10b5-1 plan that covers the time period
     from July to December 2005.

B.   RESTRICTED PERIODS OF SALE

     Beginning three weeks before the end of each quarter, and ending when the
     stock market opens on the third business day after the company issues its
     press release announcing earnings for the quarter (i.e. no sales should
     take place during RSA Security's company blackout).

C.   ACCEPTABLE PERIODS OF SALE, SHARE AMOUNTS & PRICE LIMITS

     In total, the directions and orders below in Orders 1-4 allow for the
     exercise and sale of up to a total of 364,754 options of RSA Security, Inc.
     for the duration of this plan. All orders are to be placed in my Deutsche
     Bank Alex. Brown account entitled, "Charles R. Stuckey & Marilyn Y. Stuckey
     TTEES Charles R. Stuckey Revocable Trust" (Act. #). I understand that
     Deutsche Bank Alex. Brown is a market maker in RSAS and that the limits
     below are net of commission. If the "options used" were exercised & sold
     under my previous 10B5-1 plan dated May 27, 2004 the corresponding orders
     in this plan should be considered null & void.

<PAGE>

     During any open selling period:

ORDER #1 Sell 134,421 shares of RSAS @ $23.00
Options Used:

13,845 from Grant #: 94-81, Grant Date: 01-24-1996, Grant Strike: $16.50833,
Expire 01-23-06
71,538 from Grant #: 94-81A, Grant Date: 01-24-1996, Grant Strike: $16.50833,
Expire 01-23-06
49,038 from Grant #: 94-81A, Grant Date: 01-24-1996, Grant Strike: $16.50833,
Expire 01-23-06

ORDER # 2 Sell 143,076 shares of RSAS @ $24.00
Options Used:

71,538 from Grant #: 94-81A, Grant Date: 01-24-1996, Grant Strike: $16.50833,
Expire 01-23-06
71,538 from Grant #: 94-81A, Grant Date: 01-24-1996, Grant Strike: $16.50833,
Expire 01-23-06

ORDER # 3 Sell 31,639 shares of RSAS @ $25.00
Options Used:

709 Grant #: 94-1018, Grant Date: 1-6-1999, Grant Strike: $17.25, Expire
01-05-06
12,180 Grant #: 94-1018A, Grant Date: 1-6-1999, Grant Strike: $17.25, Expire
01-05-06
2,567 Grant #: 98-261, Grant Date: 10-13-1999, Grant Strike: $19.875, Expire
01-13-06
16,183 Grant #: 98-261A, Grant Date: 10-13-1999, Grant Strike: 19.875, Expire
01-13-06

ORDER # 4 Sell 55,618 shares of RSAS @ $26.00
Options Used:

105, Grant #: R94-1026, Grant Date: 06-18-2002, Grant Strike: $4.42
48,482, Grant #: R94-1026A, Grant Date: 06/18/2002, Grant Strike: $4.42
Options: 6,926 Grant #: R94-1026A, Grant Date: 06-18-2002, Grant Strike: $4.42,
Vest 09-18-04
Options: 105 Grant #: R94-1026, Grant Date: 06-18-2002, Grant Strike: $4.42,
Vest 09-18-04

Additional instructions:

     -    The maximum number of shares that I wish to sell on any given day is
          40,000

     -    In the event that this plan is extended through year end 2005, any
          options which are expiring in January 2006 should be sold at a minimum
          of $1 over the grant price. This selling should commence 30 days prior
          to the blackout period that begins in December 2005. At that point,
          the 40,000 share per day limit is removed.

I have directed RSAS as soon as practicable, to notify Deutsche Bank Alex, Brown
and me of any circumstance pursuant to which a sale of shares by me in
accordance with the terms of the plans described above could be expected either
to: (a) result in violation by me or RSAS of Regulation M promulgated pursuant
to the Securities Act of 1933, or (b) result in the inability of RSAS to qualify
for "pooling treatment" under applicable U.S. accounting guidelines with respect
to a transaction that the Company considers imminent. Following my receipt of
any such notice that I am to suspend trading, I will

<PAGE>

instruct Deutsche Bank Alex. Brown not to sell any shares under this plan until
I am advised in writing by the Company that the suspension has been terminated.

<PAGE>

ADVANCED INSTRUCTION TO SELL COMMON STOCK

To:   Deutsche Bank Alex. Brown
      A Division of Deutsche Bank Securities Inc.

Account Number:
                ------------------------

     I am a holder of shares and options to acquire shares, of the common stock
RSA Security, Inc. (Tkr: RSAS). I would like to periodically sell Company shares
in order to diversify my portfolio. I also wish to take advantage of Rule 10b5-1
under the Securities Exchange Act of 1934, as amended, which provides for an
affirmative defense from insider trading liability for purchases and sales
effected pursuant to a contract, instruction or plan entered into when a person
is not aware of any material nonpublic information. This instruction
("Instruction") is intended to constitute a "written plan for trading
securities" within the meaning of Rule 10b5-1.

     I hereby instruct Deutsche Bank Securities Inc. (referred to herein as
"Deutsche Bank Alex. Brown") to sell currently held shares of Common Stock/Stock
options, pursuant to the specific instructions set forth in the attached memo.
My orders here under are given to you on a not held basis, meaning that you
shall use your best judgement in the execution of each order, and that you shall
be relieved of all responsibility with respect to the time of execution or the
price or prices of execution. I understand that in exercising such judgement, it
is possible that you may not sell some or all of the shares that you are
authorized hereunder to sell in any given period under this Instruction.

     You are authorized to make deliveries of securities and payment of moneys
in accordance with your normal practice. All shares to be sold shall have been
previously deposited into my account, and you shall not be required to follow
this Instruction if shares are not present in my account (or acceptable
arrangements to deliver option shares have not been made) prior to the dates on
which sales shall occur. If this Instruction requires you to exercise stock
options you shall do so in accordance with your normal procedures, and unless
instructed otherwise, remit the exercise price and the withholding tax as
calculated by the Company. In no instance should you exercise options that are
not in the money. The share amount listed above shall be increased or decreased
to reflect stock splits should they occur. I understand that I shall be
responsible to arrange for any filings that may be required under applicable law
(e.g., Form 144, Schedule 13D, and Forms 4 and 5), and that I may be subject to
the short swing profit rules contained in Section 16 of the Securities Exchange
Act of 1934. In this connection, I understand that upon my request, you will
assist me in making advance arrangements regarding the filing of Forms 144;
provided that you agree to notify me and a designated representative of RSA's
legal department within eight hours of making any trade so that I may file the
required Form 4 in a timely fashion:

     -    Margaret Seif: Phone: 781-515-5403; email: mseif@rsasecurity.com

     -    Kathryn Leach: Phone: 781-515-5422; email: kleach@rsasecurity.com

     -    Chris Dollase: Phone: 781-515-5507; email: cdollase@rsasecurity.com

     All sales shall be effected in your normal fashion in accordance with your
terms and conditions for my account and risk. You may act as principal in any
transaction hereunder. I understand that you may not be able to make all of the
sales contemplated under this Instruction due to a market disruption or a legal,
regulatory or contractual restriction applicable to you or any other event or
circumstance. I further understand that even in the absence of such a
circumstance, you may be unable to make sales consistent with ordinary
principles of best execution due to insufficient volume of trading or other
market factors in effect on the date of a sale. I hereby ratify and confirm any
and all transactions with you in accordance with this Instruction. I also agree
to indemnify and hold Deutsche Bank Alex. Brown harmless from any and all losses
arising from any cause of action arising from its performance of this
Instruction. For purposes of this Section, the term "losses" shall mean monetary
damages for which a court or regulatory agency has found Deutsche Bank to be
finally liable, after all appeals have been exhausted, but which shall in no
event exceed an amount equal to the proceeds received by me in connection with
exercises of stock options and sales of shares pursuant to this Instruction.
Notwithstanding the foregoing, "losses" shall not include

<PAGE>

Deutsche Bank's attorneys fees, and Deutsche Bank may not settle any action for
which it will claim indemnification from me without my prior written consent.

     You will cease making sales under this Instruction as soon as practicable
following receipt of written notice from the Company, confirmed by telephone,
that the Company has entered into a transaction that results in my being subject
to trading restrictions. You shall resume making sales in accordance with this
Instruction as soon as practicable after you receive written notice from the
Company of the cessation or termination of any such trading restriction. Any
sales not made as a result of the imposition of any trading restriction shall be
sold in the next following selling period.

     While this Instruction is in effect I will not enter into or alter any
corresponding or hedging transaction or position with respect to the Common
Stock (including any securities convertible or exchangeable into Common Stock).
I agree that until this Instruction has been terminated I will not enter into a
binding contract with respect to the purchase or sale of Common Stock with
another broker, dealer or financial institution, instruct any broker, dealer or
financial institution to purchase or sell Common Stock or adopt a trading plan
with respect to Common Stock other than this Instruction.

     I represent and warrant that I am not presently aware of any material
nonpublic information regarding the Company or its securities and that I am
currently able to sell Common Stock under the Company's insider trading policies
and covenant that I will not discuss or otherwise disclose material nonpublic
information to my investment representative or any other of your personnel
responsible for carrying out this Instruction. I have obtained the approval of
the Company's counsel to enter into this Instruction.

     This Instruction may be modified, terminated or amended only by a writing
signed by the parties hereto. Any modification or amendment of this Instruction
may only occur at a time when I am not aware of material nonpublic information
concerning the Company or its securities and I am otherwise permitted to make
sales under the Company's insider trading policies. If this Instruction is
modified or amended, or if I establish a new plan after termination of this
Instruction, no sales shall be made during the sixty (60) calendar days
immediately following such modification, amendment or termination (other than
sales already provided for in the Instruction prior to modification, amendment
or termination).

     This Instruction shall not be effective until Deutsche Bank Alex. Brown
confirms its acceptance in writing by signing below. It shall remain in full
force and effect until revoked or modified by me in writing. Deutsche Bank Alex.
Brown may decline to act hereunder upon reasonable notice. I hereby irrevocably
authorize you to accept any instruction from the Company to cease or suspend
sales hereunder.


                                        /s/ Charles R. Stuckey, Jr.
                                        ----------------------------------------
                                        Charles R. Stuckey, Jr.


Accepted
Deutsche Bank Alex. Brown


----------------------------------
Stuart C. Williams, Branch Manager

Dated:
       ---------------------------