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                                                                   EXHIBIT 10.10

                      RESTRICTED STOCK PURCHASE AGREEMENT

     This Agreement is made and entered into as of January 3, 2000 (the
"Effective Date") by and between Chain Link Technologies, Inc. (the "Company"),
a Delaware corporation, and Bryan Plug (the "Purchaser").

     1.   PURCHASE OF SHARES.  On the Effective Date and subject to the terms
          ------------------
and conditions of this Agreement, Purchaser hereby purchases from the Company,
and Company hereby sells to Purchaser, an aggregate of One Million Six Hundred
Forty-Five Thousand (1,645,000) shares of the Company's Common Stock $0.001, par
value per share, (the "Shares") at an aggregate purchase price of One Million
Six Hundred Forty-Five Thousand Dollars ($1,645,000.00) (the "Purchase Price")
or One Dollar ($1.00) per Share (the "Purchase Price Per Share").  As used in
this Agreement, the term "Shares" refers to the Shares purchased under this
Agreement and includes all securities received (i) in replacement of the Shares,
(ii) as a result of stock dividends or stock splits with respect to the Shares,
and (iii) in replacement of the Shares in a merger, recapitalization,
reorganization or similar corporate transaction.

     2.   PAYMENT OF PURCHASE PRICE; CLOSING.
          ----------------------------------

          2.1  Deliveries by Purchaser.  Purchaser hereby delivers to the
               -----------------------
Company:  (i) a duly executed copy of this Agreement, (ii) two (2) copies of a
blank Stock Power and Assignment Separate from Stock Certificate in the form of
Exhibit 1 attached hereto (the "Stock Powers"), both executed by Purchaser (and
---------
Purchaser's spouse, if any), (iii) if Purchaser is married, a Spouse Consent in
the form of Exhibit 2 attached hereto (the "Spouse Consent") duly executed by
            ---------
Purchaser's spouse, and (iv) payment of the Purchase Price in cash, by check in
the amount of One Thousand Six Hundred Forty-Five Dollars ($1,645.00), a copy of
which is attached hereto as Exhibit 4 and by delivery to the Company of a
                            ---------
Secured Full Recourse Promissory Note in the principal amount of One Million Six
Hundred Forty-Three Thousand Three Hundred Fifty-Five Dollars ($1,643,355.00) in
the form attached hereto as Exhibit 5, duly executed by Purchaser (the "Note");
                            ---------
and (v) a Stock Pledge Agreement in the form attached hereto as Exhibit 6, duly
                                                                ---------
executed by Purchaser (the "Pledge Agreement").

          2.2  Deliveries by the Company.  Upon its receipt of the entire
               -------------------------
Purchase Price and all the documents to be executed and delivered by Purchaser
to the Company under Section 2.1, the Company will issue a duly executed stock
certificate evidencing the Shares in the name of Purchaser, registered in
Purchaser's name in accordance with Section 14, with such certificate to be
placed in escrow as provided in Section 8 until expiration or termination of
both the Company's Repurchase Option and Right of First Refusal described in
Sections 5 and 6 and payment in full to the Company of all sums due under the
Note.

     3.   REPRESENTATIONS AND WARRANTIES OF PURCHASER.  Purchaser represents and
          -------------------------------------------
warrants to the Company that:

          3.1  Purchase for Own Account for Investment.  Purchaser is purchasing
               ---------------------------------------
the Shares for Purchaser's own account for investment purposes only and not with
a view to, or for

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sale in connection with, a distribution of the Shares within the meaning of the
Securities Act of 1933, as amended (the "1933 Act"). Purchaser has no present
intention of selling or otherwise disposing of all or any portion of the Shares
and no one other than Purchaser has any beneficial ownership of any of the
Shares.

          3.2  Access to Information.  Purchaser has had access to all
               ---------------------
information regarding the Company and its present and prospective business,
assets, liabilities and financial condition that Purchaser reasonably considers
important in making the decision to purchase the Shares, and Purchaser has had
ample opportunity to ask questions of the Company's representatives concerning
such matters and this investment.

          3.3  Understanding of Risks.  Purchaser is fully aware of:  (i) the
               ----------------------
highly speculative nature of the investment in the Shares; (ii) the financial
hazards involved; (iii) the lack of liquidity of the Shares and the restrictions
on transferability of the Shares (e.g., that Purchaser may not be able to sell
                                  ----
or dispose of the Shares or use them as collateral for loans); (iv) the
qualifications and backgrounds of the management of the Company; and (v) the tax
consequences of investment in the Shares.

          3.4  Purchaser's Qualifications.  Purchaser has a preexisting personal
               --------------------------
or business relationship with the Company and/or certain of its officers and/or
directors of a nature and duration sufficient to make Purchaser aware of the
character, business acumen and general business and financial circumstances of
the Company and/or such officers and directors.  By reason of Purchaser's
business or financial experience, Purchaser is capable of evaluating the merits
and risks of this investment, has the ability to protect Purchaser's own
interests in this transaction and is financially capable of bearing a total loss
of this investment.

          3.5  No General Solicitation.  At no time was Purchaser presented with
               -----------------------
or solicited by any publicly issued or circulated newspaper, mail, radio,
television or other form of general advertising or solicitation in connection
with the offer, sale and purchase of the Shares.

          3.6  Compliance with Securities Laws.  Purchaser understands and
               -------------------------------
acknowledges that, in reliance upon the representations and warranties made by
Purchaser herein, the Shares are not being registered with the Securities and
Exchange Commission ("SEC") under the 1933 Act or being qualified under the
California Corporate Securities Law of 1968, as amended (the "Law"), but instead
are being issued under an exemption or exemptions from the registration and
qualification requirements of the 1933 Act and the Law or other applicable state
securities laws which impose certain restrictions on Purchaser's ability to
transfer the Shares.

          3.7  Restrictions on Transfer.  Purchaser understands that Purchaser
               ------------------------
may not transfer any Shares unless such Shares are registered under the 1933 Act
and qualified under the Law or other applicable state securities laws or unless,
in the opinion of counsel to the Company, exemptions from such registration and
qualification requirements are available.  Purchaser understands that only the
Company may file a registration statement with the SEC or the California
Commissioner of Corporations or other applicable state securities commissioners
and that the Company is under no obligation to do so with respect to the Shares.
Purchaser has also

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been advised that exemptions from registration and qualification may not be
available or may not permit Purchaser to transfer all or any of the Shares in
the amounts or at the times proposed by Purchaser.

          3.8  Rule 144.  In addition, Purchaser has been advised that SEC Rule
               --------
144 promulgated under the 1933 Act, which permits certain limited sales of
unregistered securities, is not presently available with respect to the Shares
and, in any event, requires that the Shares be held for a minimum of one (1)
year, and in certain cases two (2) years, after they have been purchased and
                                                                         ---
paid for (within the meaning of Rule 144), before they may be resold under Rule
--------
144.  Purchaser understands that Rule 144 may indefinitely restrict transfer of
the Shares so long as Purchaser remains an "affiliate" of the Company and
"current public information" about the Company (as defined in Rule 144) is not
publicly available.  Purchaser understands that Shares paid for with a Note may
not be deemed to be fully "paid for" within the meaning of Rule 144 unless
certain conditions are met and that, accordingly, the Rule 144 holding period of
such Shares may not begin to run until such Shares are fully paid for within the
meaning of Rule 144.

          3.9  Rule 701.  The Shares will become freely tradable by non-
               --------
affiliates under SEC Rule 701 promulgated under the 1933 Act, subject to limited
conditions regarding the method of sale, ninety (90) days after the first sale
of Common Stock of the Company to the general public pursuant to a registration
statement filed with and declared effective by the SEC, subject to the lengthier
market standoff agreement contained in this Agreement or any other agreement
entered into by Purchaser.  Affiliates must comply with the provisions (other
than the holding period requirements) of Rule 144.

     4.   COMPLIANCE WITH CALIFORNIA SECURITIES LAWS.  THE SALE OF THE
          ------------------------------------------
SECURITIES THAT ARE THE SUBJECT OF THIS AGREEMENT, IF NOT YET QUALIFIED WITH THE
CALIFORNIA COMMISSIONER OF CORPORATIONS AND NOT EXEMPT FROM SUCH QUALIFICATION,
IS SUBJECT TO SUCH QUALIFICATION, AND THE ISSUANCE OF SUCH SECURITIES, AND THE
RECEIPT OF ANY PART OF THE CONSIDERATION THEREFOR PRIOR TO SUCH QUALIFICATION IS
UNLAWFUL UNLESS THE SALE IS EXEMPT. THE RIGHTS OF THE PARTIES TO THIS AGREEMENT
ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION BEING OBTAINED OR AN EXEMPTION
BEING AVAILABLE.

     5.   COMPANY'S REPURCHASE OPTION.  The Company or its assignees shall have
          ---------------------------
the option to repurchase all or a portion of the Unvested Shares (as defined
below) on the terms and conditions set forth in this Section (the "Repurchase
Option") if Purchaser ceases to be employed by the Company (as defined herein)
for any reason, or no reason, including without limitation Purchaser's death,
disability, voluntary resignation or termination by the Company with or without
cause.

          5.1  Definition of "Employed by the Company"; "Termination Date".  For
               ----------------------------------------------------------
purposes of this Agreement, Purchaser will be considered to be "employed by the
Company" if the Board of Directors of the Company determines that Purchaser is
rendering substantial services as an officer, employee, consultant or
independent contractor to the Company or to any

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parent, subsidiary or affiliate of the Company. In case of any dispute as to
whether Purchaser is employed by the Company, the Board of Directors of the
Company shall have sole discretion to determine whether Purchaser has ceased to
be employed by the Company or any parent, subsidiary or affiliate of the Company
and the effective date on which Purchaser's employment terminated (the
"Termination Date").

          5.2  Unvested and Vested Shares.  Shares that are vested pursuant to
               --------------------------
the schedule set forth herein are "Vested Shares".  Shares that are not vested
pursuant to the schedule set forth herein are "Unvested Shares".  Unvested
Shares may not be sold or otherwise transferred by Purchaser without the
Company's prior written consent.  On the Effective Date all of the Shares will
be Unvested Shares.  If Purchaser has continuously been employed by the Company
or any Subsidiary or Parent of the Company, at all times from the Effective Date
until July 3, 2000 (the "First Vesting Date"), then on the First Vesting Date
twelve and half percent (12.5%) of the Shares will become Vested Shares; and
thereafter, for so long (and only for so long) as Purchaser remains continuously
employed by the Company or any Subsidiary or Parent of the Company, at all times
after the First Vesting Date, an additional two and eighty three thousandths
percent (2.083) of the Shares will become Vested Shares upon the expiration of
each full calendar month elapsed after the First Vesting Date.

          If the Company does not achieve a total market valuation of Two
Billion Dollars ($2,000,000,000), as calculated at the end of the business day,
on or before February 15, 2002 and sustain such market valuation for five (5)
consecutive business days, then the Company will have the option to repurchase
from Purchaser (or from Purchaser's personal representative, as the case may be)
Seventy-Five Thousand (75,000) of the Shares at the Repurchase Option Price (as
defined in Section 5.5 below).

          No Shares will become Vested Shares after the Termination Date.  If
the application of the vesting percentage results in a fractional share, such
share shall be rounded up to the nearest whole share for each month except for
the last month in such vesting period, at the end of which last month the
balance of Unvested Shares shall become fully Vested Shares.

          5.3  Acceleration of Vesting Schedule.
               --------------------------------

          (a)  Notwithstanding any other provision of this Agreement, in the
event of a "Change of Control" (as defined below) of the Company (or its
successor), on the closing date of the "Change of Control" event, Fifty Percent
(50%) of Purchaser's then Unvested Shares shall be accelerated and shall
immediately become Vested Shares.  "Change of Control" shall mean: (i) the sale,
lease, conveyance or other disposition of all or substantially all of the
Company's assets to any person, entity or group of persons acting in concert
other than in the ordinary course of business; (ii) a merger or consolidation of
the Company with or into any other corporation or corporations in which the
Company is not the surviving corporation (other than a merger or consolidation
                                          ----------
with a wholly-owned subsidiary, a reincorporation of the Company in a different
jurisdiction, or other transaction in which there is no substantial change in
the stockholders of the Company or their relative stock holdings), or (iii) any
transaction or series of related transactions (as a result of a tender offer,
merger, consolidation or otherwise) that results in any Person (as defined in
Section 13(h)(8)(E) under the Securities Exchange Act of 1934) becoming the

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beneficial owner (as defined in Rule 13d-3 under the Securities Exchange Act of
1934), directly or indirectly, of 50% or more of the aggregate voting power of
all classes of equity of the Company.  The remaining Fifty Percent (50%) of
Purchaser's then Unvested Shares shall be accelerated and become Vested Shares
if, prior to or within thirty (30) days after the closing of such a Change of
Control event, any successor corporation or entity shall not offer Purchaser a
position having aggregate compensation similar to that Purchaser had with the
Company as of just prior to the closing of the Change of Control event.

          5.4  Adjustments.  The number of Shares that are Vested Shares or
               -----------
Unvested Shares will be proportionally adjusted to reflect any stock dividend,
stock split, reverse stock split or recapitalization of the common stock of the
Company occurring after the Effective Date.

          5.5  Exercise of Repurchase Option at Original Price.  At any time
               -----------------------------------------------
within ninety (90) days after the Termination Date, the Company may elect to
repurchase any or all of the Unvested Shares by giving Purchaser written notice
of exercise of the Repurchase Option.  The Company and/or its assignee(s) will
then have the option to repurchase from Purchaser (or from Purchaser's personal
representative, as the case may be) any or all of the Unvested Shares at the
Purchase Price Per Share specified in Section 1 above, as adjusted to reflect
any stock dividend, stock split, reverse stock split or recapitalization of the
common stock of the Company occurring after the Effective Date (the "Repurchase
Option Price").

          5.6  Payment of Repurchase Price.  The Repurchase Option Price will be
               ---------------------------
payable, at the option of the Company or its assignee(s), by check or by
cancellation of all or a portion of any outstanding indebtedness owed by
Purchaser to the Company (or to such assignee) or by any combination thereof.
The Repurchase Option Price will be paid without interest within ninety (90)
days after the Company gives the Purchaser written notice of the exercise of its
Repurchase Option.

          5.7  Right of Termination Unaffected.  Nothing in this Agreement will
               -------------------------------
be construed to limit or otherwise affect in any manner whatsoever the right or
power of the Company (or any parent, subsidiary or affiliate of the Company) to
terminate Purchaser's employment with the Company (or any parent, subsidiary or
affiliate of the Company) at any time for any reason or no reason, with or
without cause.

     6.   RIGHT OF FIRST REFUSAL.  Unvested Shares may not be sold or otherwise
          ----------------------
transferred by Purchaser without the Company's prior written consent.  Before
any Vested Shares held by Purchaser or any transferee of such Vested Shares
(either sometimes referred to herein as the "Holder") may be sold or otherwise
transferred (including without limitation a transfer by gift or operation of
law), the Company and/or its assignee(s) will have a right of first refusal to
purchase the Shares to be sold or transferred (the "Offered Shares") on the
terms and conditions set forth in this Section (the "Right of First Refusal").

          6.1  Notice of Proposed Transfer.  The Holder of the Offered Shares
               ---------------------------
will deliver to the Company a written notice (the "Notice") stating:  (i) the
Holder's bona fide intention to sell or otherwise transfer the Offered Shares;
(ii) the name and address of each

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proposed purchaser or other transferee (the "Proposed Transferee"); (iii) the
number of Offered Shares to be transferred to each Proposed Transferee; (iv) the
bona fide cash price or other consideration for which the Holder proposes to
transfer the Offered Shares (the "Offered Price"); and (v) that the Holder
acknowledges this Notice is an offer to sell the Offered Shares to the Company
and/or its assignee(s) pursuant to the Company's Right of First Refusal at the
Offered Price as provided for in this Agreement.

          6.2  Exercise of Right of First Refusal.  At any time within thirty
               ----------------------------------
(30) days after the date of the Notice, the Company and/or its assignee(s) may,
by giving written notice to the Holder, elect to purchase all (or, with the
consent of the Holder, less than all) the Offered Shares proposed to be
transferred to any one or more of the Proposed Transferees named in the Notice,
at the purchase price determined in accordance with subsection 6.3 below.

          6.3  Purchase Price.  The purchase price for the Offered Shares
               --------------
purchased under this Section will be the Offered Price, provided that if the
Offered Price consists of no legal consideration (as, for example, in the case
of a transfer by gift), the purchase price will be the fair market value of the
Offered Shares as determined in good faith by the Company's Board of Directors.
If the Offered Price includes consideration other than cash, then the value of
the non-cash consideration, as determined in good faith by the Company's Board
of Directors, will conclusively be deemed to be the cash equivalent value of
such non-cash consideration.

          6.4  Payment.  Payment of the purchase price for the Offered Shares
               -------
will be payable, at the option of the Company and/or its assignee(s) (as
applicable), by check or by cancellation of all or a portion of any outstanding
indebtedness owed by the Holder to the Company (or to such assignee, in the case
of a purchase of Offered Shares by such assignee) or by any combination thereof.
The purchase price will be paid without interest within sixty (60) days after
the Company's receipt of the Notice, or, at the option of the Company and/or its
assignee(s), in the manner and at the time(s) set forth in the Notice.

          6.5  Holder's Right to Transfer.  If Holder has not consented to the
               --------------------------
purchase of less than all of the Offered Shares proposed in the Notice to be
transferred to a given Proposed Transferee by the Company and/or its assignee(s)
as provided in this Section, then the Holder may sell or otherwise transfer all
such Offered Shares to each Proposed Transferee at the Offered Price or at a
higher price (and if Holder consented to the purchase of less than all the
Offered Shares proposed in the Notice to be transferred to a given Proposed
Transferee by the Company and/or its assignee(s) as provided in this Section,
then the Holder may sell or otherwise transfer any remaining Offered Shares to
each Proposed Transferee at the Offered Price or at a higher price), provided
                                                                     --------
that (i) such sale or other transfer is consummated within one hundred twenty
(120) days after the date of the Notice, (ii) any such sale or other transfer is
effected in compliance with all applicable securities laws, and (iii) each
Proposed Transferee agrees in writing that the provisions of this Section will
continue to apply to the Offered Shares in the hands of such Proposed
Transferee.  If the Offered Shares described in the Notice are not transferred
to each Proposed Transferee within such one hundred twenty (120) day period,
then a new Notice must be given to the Company, pursuant to which the Company
will again be offered

                                       6
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the Right of First Refusal before any Shares held by the Holder may be sold or
otherwise transferred.

          6.6  Exempt Transfers.  Notwithstanding anything to the contrary in
               ----------------
this Section, the following transfers of Vested Shares will be exempt from the
Right of First Refusal: (i) the transfer of any or all of the Vested Shares
during Purchaser's lifetime by gift or on Purchaser's death by will or intestacy
to Purchaser's "Immediate Family" (as defined below) or to a trust for the
benefit of Purchaser or Purchaser's Immediate Family, provided that each
transferee or other recipient agrees in a writing satisfactory to the Company
that the provisions of this Section will continue to apply to the transferred
Vested Shares in the hands of such transferee or other recipient; (ii) any
transfer of Vested Shares made pursuant to a statutory merger or statutory
consolidation of the Company with or into another corporation or corporations
(except that the Right of First Refusal will continue to apply thereafter to
such Vested Shares, in which case the surviving corporation of such merger or
consolidation shall succeed to the rights of the Company under this Section
unless the agreement of merger or consolidation expressly otherwise provides);
or (iii) any transfer of Vested Shares pursuant to the winding up and
dissolution of the Company.  As used herein, the term "Immediate Family" will
mean Purchaser's spouse, the lineal descendant or antecedent, father, mother,
brother or sister, child, adopted child or grandchild or adopted grandchild of
Purchaser or Purchaser's spouse, or the spouse of any child, adopted child,
grandchild or adopted grandchild of Purchaser or Purchaser's spouse or Spousal
Equivalent, as defined herein.  As used herein, a person is deemed to be a
"Spousal Equivalent" provided the following circumstances are true:  (i)
irrespective of whether or not the Purchaser and the Spousal Equivalent are the
same sex, they are the sole spousal equivalent of the other for the last twelve
(12) months, (ii) they intend to remain so indefinitely, (iii) neither are
married to anyone else, (iv) both are at least 18 years of age and mentally
competent to consent to contract, (v) they are not related by blood to a degree
of closeness that which would prohibit legal marriage in the state in which they
legally reside, (vi) they are jointly responsible for each other's common
welfare and financial obligations, and (vii) they reside together in the same
residence for the last twelve (12) months and intend to do so indefinitely.

          6.7  Termination of Right of First Refusal.  The Right of First
               -------------------------------------
Refusal will terminate as to all Shares on the effective date of the first sale
of Common Stock of the Company to the general public pursuant to a registration
statement filed with and declared effective by the SEC under the 1933 Act (other
than a registration statement relating solely to the issuance of Common Stock
pursuant to a business combination or an employee incentive or benefit plan).

          6.8  Encumbrances on Vested Shares.  Purchaser may grant a lien or
               -----------------------------
security interest in, or pledge, hypothecate or encumber Vested Shares only if
each party to whom such lien or security interest is granted, or to whom such
pledge, hypothecation or other encumbrance is made, agrees in a writing
satisfactory to the Company that:  (i) such lien, security interest, pledge,
hypothecation or encumbrance will not apply to such Vested Shares after they are
acquired by the Company and/or its assignees under this Section; and (ii) the
provisions of this Section will continue to apply to such Vested Shares in the
hands of such party and any

                                       7
<PAGE>

transferee of such party. Purchaser may not grant a lien or security interest
in, or pledge, hypothecate or encumber, any Unvested Shares.

     7.   RIGHTS AS SHAREHOLDER.  Subject to the terms and conditions of this
          ---------------------
Agreement, Purchaser will have all of the rights of a shareholder of the Company
with respect to the Shares from and after the date that Purchaser delivers
payment of the Purchase Price until such time as Purchaser disposes of the
Shares or the Company and/or its assignee(s) exercise(s) the Repurchase Option
or Right of First Refusal.  Upon an exercise of the Repurchase Option or the
Right of First Refusal, Purchaser will have no further rights as a holder of the
Shares so purchased upon such exercise, except the right to receive payment for
the Shares so purchased in accordance with the provisions of this Agreement, and
Purchaser will promptly surrender the stock certificate(s) evidencing the Shares
so purchased to the Company for transfer or cancellation.

     8.   ESCROW.  As security for Purchaser's faithful performance of this
          ------
Agreement, Purchaser agrees, immediately upon receipt of the stock
certificate(s) evidencing the Shares, to deliver such certificate(s), together
with the Stock Powers executed by Purchaser and by Purchaser's spouse, if any
(with the date and number of Shares left blank), to the Secretary of the Company
or other designee of the Company (the "Escrow Holder"), who is hereby appointed
to hold such certificate(s) and Stock Powers in escrow and to take all such
actions and to effectuate all such transfers and/or releases of such Shares as
are in accordance with the terms of this Agreement.  Escrow Holder will act
solely for the Company as its agent and not as a fiduciary.  Purchaser and the
Company agree that Escrow Holder will not be liable to any party to this
Agreement (or to any other party) for any actions or omissions unless Escrow
Holder is grossly negligent or intentionally fraudulent in carrying out the
duties of Escrow Holder under this Agreement.  Escrow Holder may rely upon any
letter, notice or other document executed with any signature purported to be
genuine and may rely on the advice of counsel and obey any order of any court
with respect to the transactions contemplated by this Agreement.  The Shares
will be released from escrow upon termination of the Repurchase Option and the
Right of First Refusal provided, however, that the Shares will be retained in
                       --------  -------
escrow so long as they are subject to the Pledge Agreement.

     9.   TAX CONSEQUENCES.  PURCHASER UNDERSTANDS THAT PURCHASER MAY SUFFER
          ----------------
ADVERSE TAX CONSEQUENCES AS A RESULT OF PURCHASER'S PURCHASE OR DISPOSITION OF
THE SHARES.  PURCHASER REPRESENTS (i) THAT PURCHASER HAS CONSULTED WITH A TAX
ADVISER THAT PURCHASER DEEMS ADVISABLE IN CONNECTION WITH THE PURCHASE OR
DISPOSITION OF THE SHARES AND (ii) THAT PURCHASER IS NOT RELYING ON THE COMPANY
FOR ANY TAX ADVICE.  Purchaser hereby acknowledges that Purchaser has been
informed that, unless an election is filed by the Purchaser with the Internal
Revenue Service (and, if necessary, the proper state taxing authorities) within
                                                                         ------
30 days of the purchase of the Shares to be effective, electing pursuant to
-------
Section 83(b) of the Internal Revenue Code (and similar state tax provisions, if
applicable) to be taxed currently on any difference between the Purchase Price
of the Shares and their fair market value on the date of purchase, there will be
a recognition of taxable income to the Purchaser, measured by the excess, if
any, of

                                       8
<PAGE>

the fair market value of the Shares, at the time they cease to be Unvested
Shares, over the Purchase Price for such Shares. Purchaser represents that
Purchaser has consulted any tax advisors Purchaser deems advisable in connection
with Purchaser's purchase of the Shares and the filing of the election under
Section 83(b) and similar tax provisions. A form of Election under Section 83(b)
is attached hereto as Exhibit 3 for reference. PURCHASER HEREBY ASSUMES ALL
                      ---------
RESPONSIBILITY FOR FILING SUCH ELECTION AND PAYING ANY TAXES RESULTING FROM SUCH
ELECTION OR FROM FAILURE TO FILE THE ELECTION AND PAYING TAXES RESULTING FROM
THE LAPSE OF THE REPURCHASE RESTRICTIONS ON THE UNVESTED SHARES.

     10.  RESTRICTIVE LEGENDS AND STOP-TRANSFER ORDERS.
          --------------------------------------------

          10.1  Legends.  Purchaser understands and agrees that the Company will
                -------
place the legends set forth below or similar legends on any stock certificate(s)
evidencing the Shares, together with any other legends that may be required by
state or federal securities laws, the Company's Certificate of Incorporation or
Bylaws, any other agreement between Purchaser and the Company or any agreement
between Purchaser and any third party:

          THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
          SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE
          SECURITIES LAWS OF CERTAIN STATES. THESE SECURITIES ARE SUBJECT TO
          RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED
          OR RESOLD EXCEPT AS PERMITTED UNDER THE ACT AND APPLICABLE STATE
          SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM.
          INVESTORS SHOULD BE AWARE THAT THEY MAY BE REQUIRED TO BEAR THE
          FINANCIAL RISKS OF THIS INVESTMENT FOR AN INDEFINITE PERIOD OF TIME.
          THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN
          FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY
          PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT AND ANY
          APPLICABLE STATE SECURITIES LAWS.

          THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN
          RESTRICTIONS ON PUBLIC RESALE AND TRANSFER, INCLUDING THE RIGHTS OF
          REPURCHASE AND FIRST REFUSAL HELD BY THE ISSUER AND/OR ITS ASSIGNEE(S)
          AS SET FORTH IN A RESTRICTED STOCK PURCHASE AGREEMENT BETWEEN THE
          ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE
          OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH PUBLIC SALE AND
          TRANSFER RESTRICTIONS, INCLUDING THE RIGHTS OF REPURCHASE AND FIRST
          REFUSAL, ARE BINDING ON TRANSFEREES OF THESE SHARES.

          THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A 180 DAY
          MARKET STANDOFF RESTRICTION AS SET FORTH IN A CERTAIN AGREEMENT
          BETWEEN THE ISSUER AND THE ORIGINAL

                                       9
<PAGE>

          HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE
          PRINCIPAL OFFICE OF THE ISSUER. AS A RESULT OF SUCH AGREEMENT, THESE
          SHARES MAY NOT BE TRADED PRIOR TO 180 DAYS AFTER THE EFFECTIVE DATE OF
          THE INITIAL PUBLIC OFFERING OF THE COMMON STOCK OF THE ISSUER HEREOF.
          SUCH RESTRICTION IS BINDING ON TRANSFEREES OF THESE SHARES.

          10.2  Stop-Transfer Instructions.  Purchaser agrees that, to ensure
                --------------------------
compliance with the restrictions imposed by this Agreement, the Company may
issue appropriate "stop-transfer" instructions to its transfer agent, if any,
and if the Company transfers its own securities, it may make appropriate
notations to the same effect in its own records.

          10.3  Refusal to Transfer.  The Company will not be required (i) to
                -------------------
transfer on its books any Shares that have been sold or otherwise transferred in
violation of any of the provisions of this Agreement or (ii) to treat as owner
of such Shares, or to accord the right to vote or pay dividends, to any
purchaser or other transferee to whom such Shares have been so transferred.

     11.  MARKET STANDOFF AGREEMENT.  Purchaser agrees in connection with any
          -------------------------
registration of the Company's securities under the 1933 Act that, upon the
request of the Company or the underwriters managing any registered public
offering of the Company's securities, Purchaser will not sell or otherwise
dispose of any Shares without the prior written consent of the Company or such
underwriters, as the case may be, for such period of time (not to exceed one
hundred eighty (180) days) after the effective date of such registration
requested by such managing underwriters and subject to all restrictions as the
Company or the managing underwriters may specify for employee-shareholders
generally.  Purchaser further agrees to enter into any agreement reasonably
required by the underwriters to implement the foregoing.

     12.  COMPLIANCE WITH LAWS AND REGULATIONS.  The issuance and transfer of
          ------------------------------------
the Shares will be subject to and conditioned upon compliance by the Company and
Purchaser with all applicable state and federal laws and regulations and with
all applicable requirements of any stock exchange or automated quotation system
on which the Company's Common Stock may be listed or quoted at the time of such
issuance or transfer.

     13.  GENERAL PROVISIONS.
          ------------------

          13.1  Assignments; Successors and Assigns.  The Company may assign any
                -----------------------------------
of its rights and obligations under this Agreement, including its rights to
repurchase Shares under the Repurchase Option and the Right of First Refusal.
Any assignment of rights and obligations by any other party to this Agreement
requires the Company's prior written consent.  This Agreement, and the rights
and obligations of the parties hereunder, will be binding upon and inure to the
benefit of their respective successors, assigns, heirs, executors,
administrators and legal representatives.

                                       10
<PAGE>

          13.2  Governing Law.  This Agreement will be governed by and construed
                -------------
in accordance with the laws of the State of California, without giving effect to
that body of laws pertaining to conflict of laws.

          13.3  Notices.  Any and all notices required or permitted to be given
                -------
to a party pursuant to the provisions of this Agreement will be in writing and
will be effective and deemed to provide such party sufficient notice under this
Agreement on the earliest of the following:  (i) at the time of personal
delivery, if delivery is in person; (ii) at the time of transmission by
facsimile, addressed to the other party at its facsimile number specified herein
(or hereafter modified by subsequent notice to the parties hereto), with
confirmation of receipt made by both telephone and printed confirmation sheet
verifying successful transmission of the facsimile; (iii) one (1) business day
after deposit with an express overnight courier for United States deliveries, or
two (2) business days after such deposit for deliveries outside of the United
States; or (iv) three (3) business days after deposit in the United States mail
by certified mail (return receipt requested) for United States deliveries.

All notices for delivery outside the United States will be sent by facsimile or
by express courier.  All notices not delivered personally or by facsimile will
be sent with postage and/or other charges prepaid and properly addressed to the
party to be notified at the address or facsimile number set forth below the
signature lines of this Agreement or at such other address or facsimile number
as such other party may designate by one of the indicated means of notice herein
to the other party hereto.  Notices by facsimile shall be machine verified as
received.

          13.4  Further Assurances.  The parties agree to execute such further
                ------------------
documents and instruments and to take such further actions as may be reasonably
necessary to carry out the purposes and intent of this Agreement.

          13.5  Titles and Headings.  The titles, captions and headings of this
                -------------------
Agreement are included for ease of reference only and will be disregarded in
interpreting or construing this Agreement.  Unless otherwise specifically
stated, all references herein to "sections" and "exhibits" will mean "sections"
and "exhibits" to this Agreement.

          13.6  Counterparts.  This Agreement may be executed in any number of
                ------------
counterparts, each of which when so executed and delivered will be deemed an
original, and all of which together shall constitute one and the same agreement.

          13.7  Severability.  If any provision of this Agreement is determined
                ------------
by any court or arbitrator of competent jurisdiction to be invalid, illegal or
unenforceable in any respect, such provision will be enforced to the maximum
extent possible given the intent of the parties hereto.  If such clause or
provision cannot be so enforced, such provision shall be stricken from this
Agreement and the remainder of this Agreement shall be enforced as if such
invalid, illegal or unenforceable clause or provision had (to the extent not
enforceable) never been contained in this Agreement.  Notwithstanding the
forgoing, if the value of this Agreement based upon the substantial benefit of
the bargain for any party is materially impaired, which determination as made by
the presiding court or arbitrator of competent jurisdiction shall be binding,
then both parties agree to substitute such provision(s) through good faith
negotiations.

                                       11
<PAGE>

          13.8  Facsimile Signatures.  This Agreement may be executed and
                --------------------
delivered by facsimile and upon such delivery the facsimile signature will be
deemed to have the same effect as if the original signature had been delivered
to the other party.  The original signature copy shall be delivered to the other
party by express overnight delivery.  The failure to deliver the original
signature copy and/or the nonreceipt of the original signature copy shall have
no effect upon the binding and enforceable nature of this Agreement.

          13.9  Amendment and Waivers.  This Agreement may be amended only by a
                ---------------------
written agreement executed by each of the parties hereto.  No amendment of or
waiver of, or modification of any obligation under this Agreement will be
enforceable unless set forth in a writing signed by the party against which
enforcement is sought.  Any amendment effected in accordance with this section
will be binding upon all parties hereto and each of their respective successors
and assigns.  No delay or failure to require performance of any provision of
this Agreement shall constitute a waiver of that provision as to that or any
other instance.  No waiver granted under this Agreement as to any one provision
herein shall constitute a subsequent waiver of such provision or of any other
provision herein, nor shall it constitute the waiver of any performance other
than the actual performance specifically waived.

     14.  TITLE TO SHARES.  The exact spelling of the name(s) under which
          ---------------
Purchaser will take title to the Shares is:

          _____________________________________________________________

          _____________________________________________________________

Purchaser desires to take title to the Shares as follows:

     [_]  Individual, as separate property

     [_]  Husband and wife, as community property

     [_]  Joint Tenants

     [_]  Tenants in Common

Purchaser's social security number is: _________________________________________

     15.  Entire Agreement.  This Agreement and the documents referred to herein
          ----------------
constitute the entire agreement and understanding of the parties with respect to
the subject matter of this Agreement, and supersede all prior understandings and
agreements, whether oral or written, between or among the parties hereto with
respect to the specific subject matter hereof.

                                       12
<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Agreement to be executed in
triplicate by its duly authorized representative and Purchaser has executed this
Agreement in triplicate, as of the Effective Date.

COMPANY                                   PURCHASER
                                          BRYAN PLUG

By: /s/ Raj Jain                          By: /s/ Bryan Plug
   -------------------------------           -----------------------------------
Name: Raj Jain                            Name: Bryan Plug
      ----------------------------              --------------------------------

Title: President                          Address:
       ---------------------------                ------------------------------

Address: 1314 Chesapeake Terrace
         -------------------------        --------------------------------------

Sunnyvale, CA 94089
----------------------------------        --------------------------------------

Fax:                                      Fax:
     -----------------------------            ----------------------------------

Phone:                                    Phone:
       ---------------------------              --------------------------------



            [Signature Page To Restricted Stock Purchase Agreement]

                                       13
<PAGE>

                               LIST OF EXHIBITS
                               ----------------

Exhibit 1:     Stock Power and Assignment Separate from Stock Certificate

Exhibit 2:     Spouse Consent

Exhibit 3:     Election Under Section 83(b) of the Internal Revenue Code

Exhibit 4:     Copy of Purchaser's Check

Exhibit 5:     Secured Full Recourse Promissory Note

Exhibit 6:     Stock Pledge Agreement

                                       14
<PAGE>

                                   EXHIBIT I
                                   ---------

                          STOCK POWER AND ASSIGNMENT

                        SEPARATE FROM STOCK CERTIFICATE

                                       15
<PAGE>


                                   EXHIBIT 2
                                   ---------

                                SPOUSE CONSENT
<PAGE>


                                   EXHIBIT 3
                                   ---------

                      ELECTION UNDER SECTION 83(b) OF THE
                             INTERNAL REVENUE CODE
<PAGE>


                                   EXHIBIT 4
                                   ---------

                           COPY OF PURCHASER'S CHECK
<PAGE>


                                   EXHIBIT 5
                                   ---------

                     SECURED FULL RECOURSE PROMISSORY NOTE
<PAGE>

                                   EXHIBIT 6
                                   ---------

                            STOCK PLEDGE AGREEMENT