EXHIBIT 4.5

                                WARRANT AGREEMENT

     Agreement  made  as  of  July  27,  2004  between  Sand  Hill  IT  Security
Acquisition Corp., a Delaware corporation,  with offices at 3000 Sand Hill Road,
Building 1, Suite 240, Menlo Park,  California 94025  ("Company"),  and American
Stock  Transfer & Trust  Company,  a New York  corporation,  with  offices at 59
Maiden Lane, New York, New York 10038 ("Warrant Agent").

     WHEREAS, the Company is engaged in a public offering ("Public Offering") of
Units  ("Units")  and, in  connection  therewith,  has  determined  to issue and
deliver  up  to  (i)  7,200,000  Warrants  ("Public  Warrants")  to  the  public
investors,  and (ii) 540,000  Warrants to Newbridge  Securities  Corporation and
I-Bankers Securities Incorporated (collectively, the "Representatives") or their
designees  ("Representative's  Warrants" and, together with the Public Warrants,
the "Warrants"), each of such Public Warrants evidencing the right of the holder
thereof to purchase one share of common stock, par value $0.01 per share, of the
Company's  Common Stock  ("Common  Stock") for $5.00,  subject to  adjustment as
described herein; and

     WHEREAS,  the Company has filed with the Securities and Exchange Commission
a Registration Statement, No. 333-114861 on Form S-1 ("Registration  Statement")
for the  registration,  under the Securities Act of 1933, as amended ("Act") of,
among other securities, the Warrants and the Common Stock issuable upon exercise
of the Warrants; and

     WHEREAS,  the Company  desires  the  Warrant  Agent to act on behalf of the
Company,  and the  Warrant  Agent is willing to so act, in  connection  with the
issuance,  registration,  transfer,  exchange,  redemption  and  exercise of the
Warrants; and

     WHEREAS,  the Company desires to provide for the form and provisions of the
Warrants,  the terms upon which  they  shall be issued  and  exercised,  and the
respective  rights,  limitation of rights,  and  immunities of the Company,  the
Warrant Agent, and the holders of the Warrants; and

     WHEREAS,  all acts and  things  have  been  done and  performed  which  are
necessary  to make the  Warrants,  when  executed  on behalf of the  Company and
countersigned  by or on behalf of the Warrant  Agent,  as provided  herein,  the
valid,  binding and legal  obligations  of the  Company,  and to  authorize  the
execution and delivery of this Agreement.

     NOW, THEREFORE, in consideration of the mutual agreements herein contained,
the parties hereto agree as follows:

1.  Appointment of Warrant Agent.  The Company hereby appoints the Warrant Agent
to act as agent for the Company for the  Warrants,  and the Warrant Agent hereby
accepts such  appointment  and agrees to perform the same in accordance with the
terms and conditions set forth in this Agreement.

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2.   Warrants.

     2.1  Form of Warrant. Each Warrant shall be issued in registered form only,
shall be in substantially the form of Exhibit A hereto,  the provisions of which
are incorporated  herein and shall be signed by, or bear the facsimile signature
of,  the  Chief  Executive  Officer,  Chairman  of the  Board or  President  and
Treasurer,  Secretary  or  Assistant  Secretary  of the Company and shall bear a
facsimile  of the  Company's  seal.  In the event  the  person  whose  facsimile
signature  has been placed  upon any  Warrant  shall have ceased to serve in the
capacity in which such person signed the Warrant  before such Warrant is issued,
it may be issued  with the same effect as if he or she had not ceased to be such
at the date of issuance.

     2.2   Effect of Countersignature.  Unless  and until  countersigned  by the
Warrant Agent pursuant to this  Agreement,  a Warrant shall be invalid and of no
effect and may not be exercised by the holder thereof.

     2.3  Registration.

          2.3.1  Warrant  Register.  The  Warrant  Agent  shall  maintain  books
("Warrant  Register"),  for  the  registration  of  original  issuance  and  the
registration  of transfer  of the  Warrants.  Upon the  initial  issuance of the
Warrants,  the Warrant  Agent shall issue and register the Warrants in the names
of the  respective  holders  thereof  in such  denominations  and  otherwise  in
accordance with instructions delivered to the Warrant Agent by the Company.

          2.3.2 Registered Holder.  Prior to due presentment for registration of
transfer of any  Warrant,  the Company and the Warrant  Agent may deem and treat
the person in whose  name such  Warrant  shall be  registered  upon the  Warrant
Register  ("registered  holder"),  as the absolute  owner of such Warrant and of
each Warrant represented thereby  (notwithstanding  any notation of ownership or
other writing on the Warrant  Certificate  made by anyone other than the Company
or the Warrant  Agent),  for the purpose of any  exercise  thereof,  and for all
other purposes,  and neither the Company nor the Warrant Agent shall be affected
by any notice to the contrary.

     2.4 Detachability of Warrants. The securities comprising the Units will not
be  separately  transferable  until 90 days  after the date  hereof  unless  the
Representatives  inform the Company of their decision to allow earlier  separate
trading, but in no event will the Representatives  allow separate trading of the
securities comprising the Units until the Company files a Current Report on Form
8-K which  includes  an audited  balance  sheet  reflecting  the  receipt by the
Company of the gross  proceeds of the Public  Offering  including  the  proceeds
received by the Company  from the exercise of the  Underwriter's  over-allotment
option,  if the  over-allotment  option is exercised  prior to the filing of the
Form 8-K.

     2.5 Warrants and Representative's  Warrants. The Representative's  Warrants
shall have the same terms and be in the same form as the Public  Warrants except
with respect to the Warrant Price as set forth below in Section 3.1.

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3.   Terms and Exercise of Warrants

     3.1 Warrant Price.  Each Public Warrant shall,  when  countersigned  by the
Warrant Agent, entitle the registered holder thereof,  subject to the provisions
of such  Public  Warrant and of this  Warrant  Agreement,  to purchase  from the
Company the number of shares of Common  Stock  stated  therein,  at the price of
$5.00 per whole share,  subject to the adjustments  provided in Section 4 hereof
and in the last  sentence of this Section  3.1.  Each  Representative's  Warrant
shall,  when  countersigned by the Warrant Agent,  entitle the registered holder
thereof,  subject to the provisions of such Representative's Warrant and of this
Warrant  Agreement,  to purchase from the Company the number of shares of Common
Stock  stated  therein,  at the price of $6.00 per whole  share,  subject to the
adjustments  provided in Section 4 hereof.  The term "Warrant  Price" as used in
this Warrant  Agreement  refers to the price per share at which Common Stock may
be  purchased  at the time a  Warrant  is  exercised.  The  Company  in its sole
discretion may lower the Warrant Price at any time prior to the Expiration Date.

     3.2 Duration of Warrants. A Warrant may be exercised only during the period
("Exercise  Period")  commencing on the later of the consummation by the Company
of a merger, capital stock exchange, asset acquisition or other similar business
combination  ("Business  Combination") (as described more fully in the Company's
Registration Statement) or July 25, 2005, and terminating at 5:00 p.m., New York
City time on the  earlier  to occur of (i) July 25,  2009 or (ii) the date fixed
for  redemption  of the  Warrants  as  provided  in Section 6 of this  Agreement
("Expiration Date").  Except with respect to the right to receive the Redemption
Price (as set forth in Section 6  hereunder),  each Warrant not  exercised on or
before the Expiration Date shall become void, and all rights  thereunder and all
rights in respect  thereof  under  this  Agreement  shall  cease at the close of
business on the Expiration  Date. The Company in its sole  discretion may extend
the duration of the Warrants by delaying the Expiration Date.

     3.3  Exercise of Warrants.

          3.3.1  Payment.  Subject to the  provisions  of the  Warrant  and this
Warrant  Agreement,  a Warrant,  when countersigned by the Warrant Agent, may be
exercised by the registered  holder thereof by surrendering it, at the office of
the Warrant Agent,  or at the office of its successor as Warrant  Agent,  in the
Borough of Manhattan, City and State of New York, with the subscription form, as
set forth in the Warrant, duly executed,  and by paying in full, in lawful money
of the United States,  in good certified check or good bank draft payable to the
order of the Company (or as  otherwise  agreed to by the  Company),  the Warrant
Price for each full share of Common  Stock as to which the Warrant is  exercised
and any and all  applicable  taxes due in  connection  with the  exercise of the
Warrant,  the exchange of the Warrant for the Common Stock,  and the issuance of
the Common Stock.

          3.3.2  Issuance  of  Certificates.  As soon as  practicable  after the
exercise of any Warrant and the clearance of the funds in payment of the Warrant
Price,  the  Company  shall  issue to the  registered  holder of such  Warrant a
certificate  or  certificates  for the number of full shares of Common  Stock to
which he is  entitled,  registered  in such name or names as may be  directed by
him, her or it, and if such Warrant shall not have been exercised in full, a new
countersigned  Warrant for the number of shares as to which such  Warrant  shall
not have been exercised. Notwithstanding the foregoing, the Company shall not be
obligated to deliver any securities pursuant to the exercise of a Warrant unless

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a  registration  statement  under the Act with  respect to the  Common  Stock is
effective.  Warrants  may not be  exercised  by, or  securities  issued  to, any
registered holder in any state in which such exercise would be unlawful.

          3.3.3  Valid  Issuance.  All shares of Common  Stock  issued  upon the
proper  exercise of a Warrant in conformity with this Agreement shall be validly
issued, fully paid and nonassessable.

          3.3.4 Date of Issuance. Each person in whose name any such certificate
for shares of Common  Stock is issued  shall for all  purposes be deemed to have
become the holder of record of such  shares on the date on which the Warrant was
surrendered and payment of the Warrant Price was made,  irrespective of the date
of delivery of such certificate,  except that, if the date of such surrender and
payment is a date when the stock transfer books of the Company are closed,  such
person  shall be deemed to have become the holder of such shares at the close of
business on the next succeeding date on which the stock transfer books are open.

          3.3.5 Warrant Solicitation and Warrant Solicitation Fee.

               a.  The   Company  has   engaged   the   Representatives,   on  a
non-exclusive  basis, as its agents for the  solicitation of the exercise of the
Warrants.  The Company,  at its cost, will (i) assist the  Representatives  with
respect to such  solicitation,  if  requested by the  Representatives,  and (ii)
provide the  Representatives,  and direct the Company's  transfer  agent and the
Warrant Agent to deliver to the Representatives, lists of the record and, to the
extent known,  beneficial owners of the Company's  Warrants.  The Company hereby
instructs  the Warrant  Agent to  cooperate  with the  Representatives  in every
respect  in  connection  with  the  Representatives'   solicitation  activities,
including,  but  not  limited  to,  providing  to  the  Representatives,  at the
Company's  cost,  a list of record  holders of the Warrants  and  circulating  a
prospectus  or  offering  circular  disclosing  the  compensation   arrangements
referenced in Section  3.3.5(b)  below to holders of the Warrants at the time of
exercise of the  Warrants.  In addition to the  conditions  set forth in Section
3.3.5(b),  the Representatives  shall accept payment of the warrant solicitation
fee provided in Section  3.3.5(b)  only if they have provided bona fide services
to the Company in  connection  with the exercise of the Warrants and only to the
extent that an investor who exercises his Warrants specifically  designates,  in
writing,  that the  Representatives  solicited  his  exercise.  In  addition  to
soliciting,  either orally or in writing,  the exercise of Warrants by a Warrant
holder, such services may also include disseminating information,  either orally
or in  writing,  to  Warrant  holders  about the  Company  or the market for the
Company's  securities,  or  assisting  in  the  processing  of the  exercise  of
Warrants.

               b. In each instance in which a Warrant is exercised,  the Warrant
Agent shall promptly give written notice of such exercise to the Company and the
Representatives  ("Warrant Agent's Exercise  Notice").  If, upon the exercise of
any  Warrant  more than one year  from the  effective  date of the  Registration
Statement,  (i) the market price of the  Company's  Common Stock is greater than
the Warrant Price,  (ii)  disclosure of  compensation  arrangements  between the
Company and the Representatives with respect to the solicitation of the exercise
of the Warrants was made both at the time of the Public Offering and at the time
of  exercise  (by  delivery  of  the  Prospectus  or as  otherwise  required  by

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applicable law, rule or regulation), (iii) the holder of the Warrant confirms in
writing that the exercise of the Warrant was  solicited by the  Representatives,
(iv)  the  Warrant  was  not  held  in a  discretionary  account,  and  (v)  the
solicitation of the exercise of the Warrant was not in violation of Regulation M
(as  such  rule or any  successor  rule  may be in  effect  as of  such  time of
exercise)  promulgated  under the  Securities  Exchange Act of 1934, as amended,
then the Warrant Agent, simultaneously with the distribution of the Common Stock
underlying the Warrants so exercised in accordance  with the  instructions  from
the Company  following  receipt of the  proceeds to the  Company  received  upon
exercise of such Warrant(s), shall, on behalf of the Company, pay a fee of 5% of
the Warrant  Price to the  Representatives,  provided  that the  Representatives
deliver to the  Warrant  Agent  within ten (10)  business  days from the date on
which the  Representatives  have received the Warrant Agent's Exercise Notice, a
certificate that the conditions set forth the preceding  clauses (iii), (iv) and
(v) have been satisfied.  Notwithstanding the foregoing,  no fee will be paid to
the  Representatives  with respect to the exercise by the  Underwriters or their
affiliates or the Company's officers or directors of Warrants purchased by it or
them upon exercise of the Representative's Warrants and still held by any of the
Underwriters or them for its or their own account.  The  Representatives and the
Company  may at any time  during  business  hours,  examine  the  records of the
Warrant Agent, including its ledger of original Warrant certificates returned to
the Warrant Agent upon exercise of Warrants.

               c. The  provisions  of this Section  3.3.5.  may not be modified,
amended or deleted without the prior written consent of the Representatives.

4.   Adjustments.

     4.1 Stock Dividends - Split-Ups.  If after the date hereof,  and subject to
the provisions of Section 4.6 below, the number of outstanding  shares of Common
Stock is increased by a stock dividend  payable in shares of Common Stock, or by
a split-up of shares of Common  Stock,  or other  similar  event,  then,  on the
effective date of such stock dividend,  split-up or similar event, the number of
shares of Common Stock  issuable on exercise of each Warrant  shall be increased
in proportion to such increase in outstanding shares of Common Stock.

     4.2  Aggregation  of Shares.  If after the date hereof,  and subject to the
provisions of Section 4.6, the number of  outstanding  shares of Common Stock is
decreased   by  a   consolidation,   combination,   reverse   stock   split   or
reclassification  of shares of Common Stock or other similar event, then, on the
effective  date  of  such  consolidation,   combination,  reverse  stock  split,
reclassification or similar event, the number of shares of Common Stock issuable
on exercise of each Warrant shall be decreased in proportion to such decrease in
outstanding shares of Common Stock.

     4.3 Adjustments in Exercise Price.  Whenever the number of shares of Common
Stock purchasable upon the exercise of the Warrants is adjusted,  as provided in
Section 4.1 and 4.2 above,  the Warrant  Price shall be adjusted (to the nearest
cent) by multiplying such Warrant Price  immediately prior to such adjustment by
a fraction  (x) the  numerator  of which shall be the number of shares of Common
Stock  purchasable upon the exercise of the Warrants  immediately  prior to such
adjustment,  and (y) the  denominator  of which shall be the number of shares of
Common Stock so purchasable immediately thereafter.

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     4.4  Replacement  of Securities  upon  Reorganization,  etc. In case of any
reclassification  or  reorganization  of the outstanding  shares of Common Stock
(other than a change covered by Section 4.1 or 4.2 hereof or that solely affects
the par value of such shares of Common  Stock),  or in the case of any merger or
consolidation  of the Company  with or into  another  corporation  (other than a
consolidation  or merger in which the Company is the continuing  corporation and
that  does  not  result  in  any   reclassification  or  reorganization  of  the
outstanding shares of Common Stock), or in the case of any sale or conveyance to
another  corporation or entity of the assets or other property of the Company as
an entirety or substantially as an entirety in connection with which the Company
is dissolved,  the Warrant  holders shall  thereafter have the right to purchase
and receive,  upon the basis and upon the terms and conditions  specified in the
Warrants  and in lieu of the shares of Common  Stock of the Company  immediately
theretofore   purchasable  and  receivable  upon  the  exercise  of  the  rights
represented  thereby, the kind and amount of shares of stock or other securities
or   property   (including   cash)   receivable   upon  such   reclassification,
reorganization,  merger or  consolidation,  or upon a dissolution  following any
such sale or  transfer,  that the  Warrant  holder  would have  received if such
Warrant  holder had exercised his, her or its  Warrant(s)  immediately  prior to
such event;  and if any  reclassification  also results in a change in shares of
Common Stock covered by Section 4.1 or 4.2, then such  adjustment  shall be made
pursuant to Sections 4.1, 4.2, 4.3 and this Section 4.4. The  provisions of this
Section   4.4   shall   similarly   apply   to   successive   reclassifications,
reorganizations, mergers or consolidations, sales or other transfers.

     4.5 Notices of Changes in  Warrant.  Upon every  adjustment  of the Warrant
Price or the number of shares  issuable upon exercise of a Warrant,  the Company
shall give written notice thereof to the Warrant Agent, which notice shall state
the Warrant Price  resulting from such  adjustment and the increase or decrease,
if any, in the number of shares purchasable at such price upon the exercise of a
Warrant,  setting forth in reasonable  detail the method of calculation  and the
facts upon which such  calculation  is based.  Upon the  occurrence of any event
specified in Sections 4.1, 4.2, 4.3 or 4.4, then, in any such event, the Company
shall give written notice to the Warrant  holder,  at the last address set forth
for such holder in the  warrant  register,  of the record date or the  effective
date of the event. Failure to give such notice, or any defect therein, shall not
affect the legality or validity of such event.

     4.6 No Fractional Shares.  Notwithstanding  any provision contained in this
Warrant Agreement to the contrary, the Company shall not issue fractional shares
upon exercise of Warrants. If, by reason of any adjustment made pursuant to this
Section 4, the holder of any Warrant  would be  entitled,  upon the  exercise of
such Warrant,  to receive a fractional  interest in a share,  the Company shall,
upon such  exercise,  round up to the  nearest  whole  number  the number of the
shares of Common Stock to be issued to the Warrant holder.

     4.7 Form of Warrant. The form of Warrant need not be changed because of any
adjustment pursuant to this Section 4, and Warrants issued after such adjustment
may state the same  Warrant  Price and the same number of shares as is stated in
the Warrants initially issued pursuant to this Agreement.  However,  the Company
may at any time in its sole  discretion  make any  change in the form of Warrant
that the Company  may deem  appropriate  and that does not affect the  substance
thereof, and any Warrant thereafter issued or countersigned, whether in exchange
or substitution for an outstanding  Warrant or otherwise,  may be in the form as
so changed.

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5.   Transfer and Exchange of Warrants.

     5.1  Registration  of  Transfer.  The  Warrant  Agent  shall  register  the
transfer,  from  time to time,  of any  outstanding  Warrant  upon  the  Warrant
Register,  upon surrender of such Warrant for transfer,  properly  endorsed with
signatures properly  guaranteed and accompanied by appropriate  instructions for
transfer.  Upon any such transfer, a new Warrant representing an equal aggregate
number of Warrants shall be issued and the old Warrant shall be cancelled by the
Warrant Agent. The Warrants so cancelled shall be delivered by the Warrant Agent
to the Company from time to time upon request.

     5.2 Procedure for Surrender of Warrants. Warrants may be surrendered to the
Warrant  Agent,  together with a written  request for exchange or transfer,  and
thereupon  the Warrant  Agent shall issue in exchange  therefor  one or more new
Warrants as requested by the registered  holder of the Warrants so  surrendered,
representing an equal aggregate number of Warrants;  provided,  however, that in
the event that a Warrant  surrendered  for transfer bears a restrictive  legend,
the  Warrant  Agent  shall not cancel  such  Warrant  and issue new  Warrants in
exchange therefor until the Warrant Agent has received an opinion of counsel for
the Company  stating that such transfer may be made and  indicating  whether the
new Warrants must also bear a restrictive legend.

     5.3 Fractional Warrants.  The Warrant Agent shall not be required to effect
any  registration of transfer or exchange which will result in the issuance of a
warrant certificate for a fraction of a warrant.

     5.4 Service  Charges.  No service  charge shall be made for any exchange or
registration of transfer of Warrants.

     5.5 Warrant  Execution  and  Countersignature.  The Warrant Agent is hereby
authorized to countersign  and to deliver,  in accordance with the terms of this
Agreement, the Warrants required to be issued pursuant to the provisions of this
Section 5, and the Company,  whenever required by the Warrant Agent, will supply
the Warrant  Agent with Warrants duly executed on behalf of the Company for such
purpose.

6.   Redemption.

     6.1  Redemption.  Subject to Section 6.4 hereof,  with the prior consent of
the  Representatives,  not less  than  all of the  outstanding  Warrants  may be
redeemed,  at the  option  of  the  Company,  at  any  time  after  they  become
exercisable and prior to their  expiration,  at the office of the Warrant Agent,
upon the notice  referred to in Section  6.2.,  at the price of $.01 per Warrant
("Redemption Price"), provided that the last sales price of the Common Stock has
been at least $8.50 per share,  on each of twenty (20)  trading  days within any
thirty (30)  trading day period  ending on the third  business  day prior to the
date on which notice of redemption is given.  The provisions of this Section 6.1
may not be modified, amended or deleted without the prior written consent of the
Representatives.

     6.2 Date Fixed for,  and Notice of,  Redemption.  In the event the  Company
shall elect to redeem all of the Warrants,  the Company shall fix a date for the
redemption.  Notice of redemption  shall be mailed by first class mail,  postage

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prepaid,  by the  Company  not less  than 30 days  prior to the date  fixed  for
redemption  to the  registered  holders of the  Warrants to be redeemed at their
last addresses as they shall appear on the registration books. Any notice mailed
in the manner herein provided shall be  conclusively  presumed to have been duly
given whether or not the registered holder received such notice.

     6.3 Exercise After Notice of  Redemption.  The Warrants may be exercised in
accordance  with  Section  3 of this  Agreement  at any  time  after  notice  of
redemption  shall have been given by the Company pursuant to Section 6.2. hereof
and prior to the time and date fixed for redemption. On and after the redemption
date,  the record holder of the Warrants  shall have no further rights except to
receive, upon surrender of the Warrants, the Redemption Price.

     6.4 Outstanding  Warrants Only. The Company understands that the redemption
rights provided for by this Section 6 apply only to outstanding Warrants. To the
extent a person holds rights to purchase  Warrants,  such purchase  rights shall
not be  extinguished  by  redemption.  However,  once such  purchase  rights are
exercised,  the  Company  may  redeem the  Warrants  issued  upon such  exercise
provided that the criteria for redemption is met. The provisions of this Section
6.4 may not be modified, amended or deleted without the prior written consent of
the Representatives.

7.   Other Provisions Relating to Rights of Holders of Warrants.

     7.1 No Rights as  Stockholder.  A Warrant  does not entitle the  registered
holder thereof to any of the rights of a stockholder of the Company,  including,
without  limitation,  the right to receive  dividends,  or other  distributions,
exercise  any  preemptive  rights to vote or to consent or to receive  notice as
stockholders  in respect of the  meetings  of  stockholders  or the  election of
directors of the Company or any other matter.

     7.2 Lost, Stolen, Mutilated, or Destroyed Warrants. If any Warrant is lost,
stolen,  mutilated, or destroyed,  the Company and the Warrant Agent may on such
terms as to indemnity or otherwise as they may in their discretion impose (which
shall, in the case of a mutilated Warrant, include the surrender thereof), issue
a new  Warrant of like  denomination,  tenor,  and date as the  Warrant so lost,
stolen,  mutilated,  or  destroyed.  Any such new  Warrant  shall  constitute  a
substitute contractual  obligation of the Company,  whether or not the allegedly
lost, stolen,  mutilated,  or destroyed Warrant shall be at any time enforceable
by anyone.

     7.3 Reservation of Common Stock. The Company shall at all times reserve and
keep available a number of its  authorized  but unissued  shares of Common Stock
that  will be  sufficient  to permit  the  exercise  in full of all  outstanding
Warrants issued pursuant to this Agreement.

     7.4  Registration  of Common  Stock.  The Company  agrees that prior to the
commencement  of the  Exercise  Period,  it shall file with the  Securities  and
Exchange Commission a post-effective amendment to the Registration Statement, or
a new registration  statement,  for the registration,  under the Act, of, and it
shall take such action as is necessary  to qualify for sale,  in those states in
which the  Warrants  were  initially  offered by the  Company,  the Common Stock
issuable upon exercise of the Warrants. In either case, the Company will use its
best  efforts  to  cause  the  same to  become  effective  and to  maintain  the
effectiveness  of  such  registration  statement  until  the  expiration  of the
Warrants in accordance with the provisions of this Agreement.  The provisions of

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this  Section  7.4 may not be  modified,  amended or deleted  without  the prior
written consent of the Representatives.

8.   Concerning the Warrant Agent and Other Matters.

     8.1 Payment of Taxes.  The Company will from time to time  promptly pay all
taxes and charges that may be imposed  upon the Company or the Warrant  Agent in
respect of the  issuance or delivery of shares of Common Stock upon the exercise
of Warrants, but the Company shall not be obligated to pay any transfer taxes in
respect of the Warrants or such shares.

     8.2 Resignation, Consolidation, or Merger of Warrant Agent.

          8.2.1  Appointment of Successor  Warrant Agent.  The Warrant Agent, or
any successor to it hereafter appointed, may resign its duties and be discharged
from all further duties and liabilities  hereunder after giving sixty (60) days'
notice in writing to the  Company.  If the office of the Warrant  Agent  becomes
vacant by  resignation  or  incapacity  to act or  otherwise,  the Company shall
appoint in writing a successor  Warrant Agent in place of the Warrant Agent.  If
the Company shall fail to make such appointment within a period of 30 days after
it has been notified in writing of such resignation or incapacity by the Warrant
Agent or by the holder of the Warrant (who shall,  with such notice,  submit his
Warrant for inspection by the Company), then the holder of any Warrant may apply
to the Supreme Court of the State of New York for the County of New York for the
appointment  of a successor  Warrant Agent at the Company's  cost. Any successor
Warrant  Agent,  whether  appointed by the Company or by such court,  shall be a
corporation  organized and existing  under the laws of the State of New York, in
good standing and having its principal office in the Borough of Manhattan,  City
and State of New York,  and  authorized  under such laws to  exercise  corporate
trust  powers and  subject to  supervision  or  examination  by federal or state
authority.  After appointment,  any successor Warrant Agent shall be vested with
all the authority,  powers, rights,  immunities,  duties, and obligations of its
predecessor  Warrant  Agent with like effect as if  originally  named as Warrant
Agent  hereunder,  without  any  further  act or deed;  but if for any reason it
becomes  necessary or appropriate,  the predecessor  Warrant Agent shall execute
and deliver, at the expense of the Company,  an instrument  transferring to such
successor  Warrant  Agent  all  the  authority,   powers,  and  rights  of  such
predecessor  Warrant Agent hereunder;  and upon request of any successor Warrant
Agent the Company  shall  make,  execute,  acknowledge,  and deliver any and all
instruments in writing for more fully and effectually  vesting in and confirming
to such successor Warrant Agent all such authority,  powers, rights, immunities,
duties, and obligations.

          8.2.2  Notice of  Successor  Warrant  Agent.  In the event a successor
Warrant Agent shall be appointed,  the Company shall give notice  thereof to the
predecessor  Warrant Agent and the transfer agent for the Common Stock not later
than the effective date of any such appointment.

          8.2.3 Merger or  Consolidation  of Warrant Agent. Any corporation into
which the Warrant  Agent may be merged or with which it may be  consolidated  or
any corporation  resulting from any merger or consolidation to which the Warrant
Agent shall be a party shall be the successor Warrant Agent under this Agreement
without any further act.

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<PAGE>

     8.3  Fees and Expenses of Warrant Agent.

          8.3.1  Remuneration.  The  Company  agrees  to pay the  Warrant  Agent
reasonable  remuneration  for its services as such Warrant  Agent  hereunder and
will  reimburse  the  Warrant  Agent upon demand for all  expenditures  that the
Warrant Agent may reasonably incur in the execution of its duties hereunder.

          8.3.2  Further  Assurances.  The Company  agrees to perform,  execute,
acknowledge, and deliver or cause to be performed,  executed,  acknowledged, and
delivered all such further and other acts,  instruments,  and  assurances as may
reasonably  be required by the Warrant  Agent for the carrying out or performing
of the provisions of this Agreement.

     8.4  Liability of Warrant Agent.

          8.4.1 Reliance on Company  Statement.  Whenever in the  performance of
its  duties  under this  Warrant  Agreement,  the  Warrant  Agent  shall deem it
necessary or desirable  that any fact or matter be proved or  established by the
Company prior to taking or suffering any action  hereunder,  such fact or matter
(unless other evidence in respect thereof be herein specifically prescribed) may
be deemed to be conclusively proved and established by a statement signed by the
Chief Executive  Officer,  President or Chairman of the Board of the Company and
delivered to the Warrant  Agent.  The Warrant Agent may rely upon such statement
for any action taken or suffered in good faith by it pursuant to the  provisions
of this Agreement.

          8.4.2 Indemnity.  The Warrant Agent shall be liable hereunder only for
its own  negligence,  willful  misconduct  or bad faith.  The Company  agrees to
indemnify  the  Warrant  Agent  and  save  it  harmless   against  any  and  all
liabilities,  including  judgments,  costs  and  reasonable  counsel  fees,  for
anything done or omitted by the Warrant Agent in the execution of this Agreement
except as a result of the Warrant Agent's negligence, willful misconduct, or bad
faith.

          8.4.3 Exclusions.  The Warrant Agent shall have no responsibility with
respect to the  validity of this  Agreement  or with  respect to the validity or
execution of any Warrant (except its countersignature  thereof); nor shall it be
responsible for any breach by the Company of any covenant or condition contained
in this  Agreement or in any Warrant;  nor shall it be  responsible  to make any
adjustments required under the provisions of Section 4 hereof or responsible for
the manner,  method, or amount of any such adjustment or the ascertaining of the
existence of facts that would require any such  adjustment;  nor shall it by any
act  hereunder  be  deemed  to make any  representation  or  warranty  as to the
authorization or reservation of any shares of Common Stock to be issued pursuant
to this  Agreement  or any Warrant or as to whether  any shares of Common  Stock
will when issued be valid and fully paid and nonassessable.

          8.5 Acceptance of Agency.  The Warrant Agent hereby accepts the agency
established  by this Agreement and agrees to perform the same upon the terms and
conditions  herein set forth and among other things,  shall account  promptly to
the Company with respect to Warrants exercised and concurrently account for, and
pay to the Company, all moneys received by the Warrant Agent for the purchase of
shares of the Company's  Common Stock (less any warrant  solicitation fee due to

                                       10
<PAGE>

the  Representatives  pursuant to Section 3.3.5 herein)  through the exercise of
Warrants.

9.   Miscellaneous Provisions.

     9.1  Successors.  All the covenants and  provisions of this Agreement by or
for the benefit of the Company or the Warrant  Agent shall bind and inure to the
benefit of their respective successors and assigns.

     9.2 Notices.  Any notice,  statement or demand  authorized  by this Warrant
Agreement  to be given or made by the  Warrant  Agent  or by the  holder  of any
Warrant to or on the Company shall be sufficiently given when so delivered if by
hand or  overnight  delivery  or if sent by  certified  mail or private  courier
service  within  five  days  after  deposit  of such  notice,  postage  prepaid,
addressed  (until  another  address is filed in writing by the Company  with the
Warrant Agent), as follows:

         Sand Hill IT Security Acquisition Corp.
         3000 Sand Hill Road
         Building 1, Suite 240
         Menlo Park, California 94025
         Attn:    Chief Executive Officer

Any notice, statement or demand authorized by this Agreement to be given or made
by the holder of any Warrant or by the Company to or on the Warrant  Agent shall
be sufficiently  given when so delivered if by hand or overnight  delivery or if
sent by certified mail or private courier service within five days after deposit
of such notice,  postage  prepaid,  addressed (until another address is filed in
writing by the Warrant Agent with the Company), as follows:

         American Stock Transfer & Trust Company
         59 Maiden Lane
         New York, New York 10038
         Attn:    Compliance Department

with a copy in each case to:

         Dilworth Paxson LLP
         1818 N. Street, N.W.
         Suite 4000
         Washington, DC 20003
         Attn:    Ralph V. DeMartino, Esq.

                                       11
<PAGE>

and

         Jenkens & Gilchrist, P.C.
         1445 Ross Avenue
         Suite 3200
         Dallas, Texas  75202
         Attn:    Ronald J. Frappier, Esq.

and

         Newbridge Securities Corporation
         1451 West Cypress Creek Road
         Fort Lauderdale, Florida  33309
         Attn:    Guy S. Amico

         I-Bankers Securities Incorporated
         3340 Indian Creek Ct.
         Fort Worth, Texas 76180
         Attn:    Michael McCrory


     9.3 Applicable law. The validity,  interpretation,  and performance of this
Agreement  and of the Warrants  shall be governed in all respects by the laws of
the State of New York,  without  giving effect to conflict of laws.  The Company
hereby agrees that any action,  proceeding or claim against it arising out of or
relating  in any way to this  Agreement  shall be brought  and  enforced  in the
courts  of the State of New York or the  United  States  District  Court for the
Southern  District of New York, and  irrevocably  submits to such  jurisdiction,
which jurisdiction  shall be exclusive.  The Company hereby waives any objection
to such exclusive  jurisdiction  and that such courts  represent an inconvenient
forum.  Any such  process or summons to be served upon the Company may be served
by transmitting a copy thereof by registered or certified  mail,  return receipt
requested,  postage prepaid, addressed to it at the address set forth in Section
9.2 hereof. Such mailing shall be deemed personal service and shall be legal and
binding upon the Company in any action, proceeding or claim.

     9.4 Persons Having Rights under this  Agreement.  Nothing in this Agreement
expressed and nothing that may be implied from any of the  provisions  hereof is
intended,  or shall be  construed,  to confer  upon,  or give to,  any person or
corporation  other than the  parties  hereto and the  registered  holders of the
Warrants and, for the purposes of Sections 3.3.5,  6.1, 6.4, 7.4 and 9.2 hereof,
the  Representatives,  any right,  remedy,  or claim  under or by reason of this
Warrant  Agreement  or of any  covenant,  condition,  stipulation,  promise,  or
agreement  hereof.  The  Representatives  shall be  deemed  to be a  third-party
beneficiary of this Agreement with respect to Sections 3.3.5,  6.1, 6.4, 7.4 and
9.2 hereof. All covenants,  conditions,  stipulations,  promises, and agreements
contained in this Warrant  Agreement shall be for the sole and exclusive benefit
of the parties  hereto (and the  Representatives  with  respect to the  Sections
3.3.5, 6.1, 6.4, 7.4 and 9.2 hereof) and their successors and assigns and of the
registered holders of the Warrants.

     9.5 Examination of the Warrant Agreement. A copy of this Agreement shall be
available  at all  reasonable  times at the office of the  Warrant  Agent in the

                                       12
<PAGE>

Borough  of  Manhattan,  City  and  State of New  York,  for  inspection  by the
registered holder of any Warrant.  The Warrant Agent may require any such holder
to submit his Warrant for inspection by it.

     9.6  Counterparts.  This  Agreement  may  be  executed  in  any  number  of
counterparts and each of such  counterparts  shall for all purposes be deemed to
be an original,  and all such counterparts shall together constitute but one and
the same instrument.

     9.7 Effect of Headings.  The Section  headings  herein are for  convenience
only and are not  part of this  Warrant  Agreement  and  shall  not  affect  the
interpretation thereof.


                                       13

<PAGE>


     IN WITNESS  WHEREOF,  this  Agreement has been duly executed by the parties
hereto as of the day and year first above written.



                                      SAND HILL IT SECURITY
                                      ACQUISITION CORP.


                                      By:  /s/ Humphrey P. Polanen
                                           -----------------------------------
                                           Humphrey P. Polanen,
                                           Chief Executive Officer



                                      AMERICAN STOCK TRANSFER &
                                      TRUST COMPANY

                                      By:  /s/Herbert J. Lemmer
                                           -----------------------------------
                                           Name:    Herbert L. Lemmer
                                           Title:   Vice President



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