PROMISSORY
      NOTE

     

     

    
      	$10,000.00	
              Menlo
                Park, California

            	
              April
30,
                2006

            


    

    


    FOR
      VALUE
      RECEIVED, the undersigned Sand Hill IT Security Acquisition Corp., a Delaware
      corporation (“Maker”),
      promises to pay to Humphrey P. Polanen (“Payee”),
      at
      such place as Payee may from time to time designate, the aggregate principal
      sum
      of Ten Thousand and no/100ths Dollars ($10,000.00), together with interest
      on
      the unpaid principal balance of this promissory note (“Note”).

    


    1. Interest.
      The
      unpaid principal balance of this Note from time to time outstanding shall bear
      simple interest at ten percent (10%) per annum.

    


    2. Payments.
      The
      principal and all accrued and unpaid interest shall be due and payable on the
      earlier of the consummation of the merger of St. Bernard Software, Inc. and
      Sand
      Hill Merger Corp. (the “Merger”) and July 26, 2006. For purposes of the payment
      of any amounts pursuant to the terms of this Note, if such date falls on a
      day
      that is a day on which commercial banks are not authorized to be open or are
      required to be closed, then the date shall be deemed to be the next succeeding
      day where such commercial banks may remain open.

    


    3. Prepayments.
      Maker
      shall have the right to prepay, at any time without premium or penalty, in
      whole
      or in part, (a) the accrued interest and (b) the principal of this
      Note, provided that all accrued interest has first been paid.

    


    4. Events
      of Default and Remedies.
      As used
      herein, the term “Event
      of Default”
shall
      include any or all of the following if same exist on the tenth (10th) day
      after written notice by Payee to Maker which certifies such default:
      (a) nonpayment of any principal or interest upon the date same shall be due
      and payable under the terms of this Note; or (b) the adjudication of Maker
      as bankrupt, or the taking of any voluntary action by Maker or any involuntary
      action against Maker seeking an adjudication of Maker as bankrupt, or seeking
      relief by or against Maker under any provision under the Bankruptcy Code. Upon
      the occurrence and during the continuation of an Event of Default, Payee may,
      at
      his option, without further notice of nonpayment, demand for payment,
      presentment for payment, notice of intention to accelerate maturity, notice
      of
      acceleration of maturity, or any other notice or demand of any kind to Maker,
      declare the entire unpaid principal balance and accrued interest on this Note
      to
      be immediately due and payable, at which time such amounts shall become
      immediately due and payable. Payee may exercise this option to accelerate
      maturity hereof during any default by Maker regardless of any prior forbearance
      by Payee.

    


    5. Disclaimer
      of Trust Fund.
      Payee
      hereby acknowledges that Maker
      has
      established a trust fund consisting of a portion of the proceeds of Maker’s
      initial public offering, initially in the amount of approximately $21 million
      (the “Trust
      Fund”),
      for
      the benefit of the public stockholders of Maker and Maker may disburse monies
      from the Trust Fund only (a) to the public stockholders in the event of the
      redemption of their shares or the liquidation of Maker or (b) to Maker after
      it
      consummates a business combination. Payee hereby agrees that it does not have
      any right, title, interest or claim of any kind in or to any monies in the
      Trust
      Fund (“Claim”)
      and
      hereby waives any Claim it may have in the future as a result of, or arising
      out
      of, any contracts or agreements with Maker and will not seek recourse against
      the Trust Fund for any reason whatsoever.

    


    
      
         

      

      
         

        
          

        

      

      
         

      

    

    6. No
      Waiver.
      No
      delay on the part of Payee or other holder of this Note in the exercise of
      any
      power or right under this Note, shall operate as a waiver hereof, nor shall
      a
      single or partial exercise of any power or right preclude other or further
      exercise thereof or the exercise of any other power or right. Enforcement by
      the
      holder of this Note for the payment hereof shall not constitute an election
      by
      such holder of remedies so as to preclude the exercise of any other remedy
      available to such holder.

    


    7. Waiver.
      Except
      as otherwise set forth herein, Maker and all endorsers, sureties, and guarantors
      hereof hereby jointly and severally waive all exemption rights under any
      applicable law, and also waive presentment for payment, demand, notice of
      nonpayment, valuation, appraisement, protest, demand, dishonor, notice of
      protest, notice of intent to accelerate, notice of acceleration, and all other
      notices, and without further notice hereby consent to renewals, extensions,
      or
      partial payments either before or after maturity.

    


    8. Severability.
      The
      invalidity, or unenforceability in particular circumstances, of any provision
      of
      this Note shall not extend beyond such provision or such circumstances and
      no
      other provision of this Note shall be affected thereby.

    


    9. Costs
      of Collection.
      If this
      Note is placed in the hands of any attorney for collection, or is collected
      by
      suit or through probate or bankruptcy proceeding, Maker agrees to pay reasonable
      attorneys’ fees and disbursements in addition to other amounts due.

    


    10. Notices.
      All
      notices or demands required or permitted hereunder shall be in writing and
      shall
      be deemed given when actually delivered or on the third business day following
      the day on which the same shall have been mailed by registered or certified
      mail, postage prepaid, addressed to the parties at the addresses herein. Either
      Maker or Payee may change its respective address or addressee by giving notice
      of such change to the other party in the manner provided herein. For this
      purpose only, unless and until such written notice is actually received, the
      address and addressee specified for each party shall be deemed to continue
      in
      effect for all purposes.

    


    11. Governing
      Law.
      THIS
      NOTE SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE
      STATE
      OF DELAWARE WITHOUT REGARD TO CHOICE OF LAW PRINCIPLES.

    


    
      
         

      

      
         

        
          

        

      

      
         

      

    


    IN
      WITNESS WHEREOF, the undersigned has executed this Note to be effective as
      of
      the date first written above.

     

     

    
      	 	
              MAKER:

              


              SAND
                HILL IT SECURITY ACQUISITION CORPORATION

               

              


              By: /s/
                Keith Walz

              Keith
                Walz

              Chief
                Financial Officer

            


    

    
 

    Acknowledged
      and accepted on the date first written above:

    


    PAYEE:

    


    


    /s/
      Humphrey P. Polanen

    Humphrey
      P. Polanen