Exhibit 10.24

                               SECURITY AGREEMENT

     THIS SECURITY  AGREEMENT  (hereinafter  referred to as the  "Agreement") is
made as of the 14th day of August,  1996,  by GARRETT  U. COHN  ("Debtor"),  and
DIGITAL DESCRIPTOR SYSTEMS, INC., a Delaware corporation ("Secured Party").

                                    RECITALS:

     1. The Secured  Party has agreed to make a loan ("Loan") to Debtor of up to
ONE HUNDRED TWENTY-FIVE THOUSAND AND NO/100 DOLLARS ($125,000.00).

     2. The Loan is evidenced by a Secured Promissory Note ("Note") of even date
herewith made by the Debtor, to Secured Party in the maximum amount of the Loan.

     3.  Pursuant to  agreement,  Debtor has agreed to grant to Secured  Party a
security interest in that certain  promissory note described as the "Collateral"
in Exhibit A attached hereto.

     4. The Collateral will be held by the Secured Party.

     NOW,  THEREFORE,  with  reference  to the above  recitals,  and in reliance
thereon,  and for  other  good  and  valuable  consideration,  the  receipt  and
sufficiency  of which are  hereby  acknowledged,  the  parties  hereto  agree as
follows:

     1. Creation of Security Interest.

     Debtor  hereby  grants to Secured  Party a security  interest  in, and does
hereby collaterally assign,  pledge, convey and set over unto the Secured Party,
the Collateral and all of Debtor's present and hereafter  acquired right,  title
and interest in and to the  Collateral,  for the purpose of securing  payment of
all indebtedness, obligations and liabilities of Debtor to Secured Party arising
under or in  connection  with  the  Note,  and  performance  of all  agreements,
covenants, terms and conditions contained in the foregoing document.

     2. Warranties, Representations and Covenants of Debtor.

     Debtor hereby  warrants,  represents  and covenants to the Secured Party as
follows:

          (a) Debtor is and will be the sole owner of the Collateral,  free from
     any lien,  security  interest,  encumbrance  or adverse  claim of any kind.
     Debtor will not permit any financing  statement to be filed with respect to
     the  Collateral or any portion  thereof  except in favor of Secured  Party.
     Debtor  will  notify  Secured  Party of,  and will  defend  the  Collateral
     against,  all claims and  demands of all persons at any time  claiming  the
     same or any interest therein.

          (b) Subject to the terms of subparagraph  2.(d) hereof, the Collateral
     will be kept in the  possession of the Secured  Party,  and the  Collateral
     will not be removed from the Premises  without the prior written consent of
     Secured Party.

          (c) At the request of Secured  Party,  Debtor has or will join Secured
     Party  in  executing  one or  more  financing  statements  identifying  the
     Collateral  and  evidencing  the security  interest of Secured Party in the
     Collateral pursuant to the requirements of Uniform Commercial Code and in


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<PAGE>

     form satisfactory to Secured Party.  Debtor will pay the cost of filing the
     same in all public offices wherever filing is deemed by Secured Party to be
     necessary or desirable.

          (d) Except as otherwise  expressly  permitted in writing,  without the
     prior written  consent of Secured  Party,  Debtor will not sell,  exchange,
     dispose of, offer to sell or otherwise  transfer or otherwise deal with the
     Collateral  or any  portion  or  interest  therein,  unless  simultaneously
     therewith  new items of  Collateral,  which  items may be  similar to those
     proposed to be  disposed  of and which shall be of equal or greater  value,
     are substituted  therefore.  If the Collateral or any part thereof is sold,
     transferred,  exchanged,  paid  or  otherwise  disposed  of,  the  security
     interest  of  Secured  Party  shall  extend to the  proceeds  of such sale,
     transfer, exchange, payment or other disposition.

          (e)  Debtor  will keep the  Collateral  free  from any lien,  security
     interest or encumbrance. Debtor will not use the Collateral in violation of
     any statute or governmental rule, regulation or ordinance.

          (f) At the Secured Party's request,  Debtor will execute any document,
     will  procure  any  document  and will do all  other  acts  which  from the
     character or use of the Collateral  may be reasonably  necessary to protect
     the  Collateral  against the rights,  claims or interests of third persons,
     and will otherwise preserve the Collateral as security hereunder.

     3. Preservation of Collateral by Secured Party.

     Should  Debtor fail or refuse to make any  payment,  perform or observe any
other  covenant,  condition or obligation,  or take any other action required by
the terms of this  Agreement or the Note at the time or in the manner  provided,
then Secured Party may, at Secured Party's sole discretion, without notice to or
demand upon Debtor,  and without releasing Debtor from any obligation,  covenant
or condition hereof, make, perform,  observe, take or do the same in such manner
and to such extent as Secured  Party may deem  necessary to protect its security
interest  in or the  value of the  Collateral.  Furthermore,  Secured  Party may
commence,  defend,  appeal or otherwise  participate in any action or proceeding
purporting  to affect its security  interest in or the value of the  Collateral.
Debtor hereby agrees to reimburse  Secured Party on demand for any payment made,
or any expense incurred by Secured Party pursuant to the foregoing authorization
(including court costs and reasonable  attorneys' fees and  disbursements),  and
agrees  further  to pay  interest  thereon  from  the  date of said  payment  or
expenditure at the rate specified in the Note as the Default Rate.

     4. Default.

     The  occurrence  of  any  of  the  following  shall  constitute  a  default
("Default") hereunder:

          (a) If a Default  shall occur under the Note and be  continuing  or if
     Debtor  fails to observe or perform any term,  covenant or condition of the
     Note,  and such  default  is not cured  within  the time  period  expressly
     established therefor, if any; or

          (b) If any writ or any  distress  warrant  shall be issued  against or
     levied on the Collateral,  or any part thereof; or if the Debtor shall sell
     or assign or  attempt  to sell or assign the  Collateral,  or any  interest
     therein in violation of subparagraph  2.(d) hereof,  which events shall not
     be corrected or cured by Debtor  within ten (10) days after notice  thereof
     by Secured Party; or


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<PAGE>

          (c) If Debtor  defaults  under this  Agreement,  which  default is not
     corrected or cured by Debtor  within ten (10) days after notice  thereof by
     Secured Party; or

          (d) If the  Collateral or any part thereof is removed or  transferred,
     or attempted to be removed or  transferred,  from the Premises,  or sold or
     disposed of, in violation  of the terms of  subparagraphs  2.(b) and 2.(d),
     and substitute  Collateral is not provided within ten (10) days thereafter;
     or

          (e) If any representation or warranty made by Debtor herein, or in any
     other instrument, agreement or written statement in any way related hereto,
     to the Collateral or any portion  thereof,  or to the Loan,  shall prove to
     have been false or incorrect  in any material  respect on or after the date
     when made.

     5. Remedies upon Default.

     Upon  the  occurrence  of  Default,  Secured  Party  may,  in  addition  to
exercising those remedies  specified in the Notes, at any time, at its election,
without  further  notice,  and to the extent  permitted by law pursue any one or
more of the following remedies concurrently or successively, it being the intent
hereof that none of such remedies shall be to the exclusion of any others:

          (a) Foreclose this Agreement and the security interest granted hereby,
     as provided herein,  or in any manner permitted by law, either  personally,
     through  agents  or by means of a court  appointed  receiver,  and  exclude
     therefrom  Debtor and all others  claiming  through  or under  Debtor,  and
     exercise  any and all of the rights and  remedies  conferred  upon  Secured
     Party by the Note or by  applicable  law,  either  concurrently  or in such
     order as Secured Party may  determine.  Secured Party may sell or otherwise
     dispose of, or cause to be sold or otherwise disposed of the Collateral, as
     a whole or in such parcels as Secured Party may determine without affecting
     in any way the rights or  remedies to which  Secured  Party may be entitled
     under the Note or applicable law;

          (b) Publicly or privately sell or otherwise dispose of the Collateral,
     without  necessarily  having  the  Collateral  at  the  place  of  sale  or
     disposition,  and upon  terms  and in such  manner  as  Secured  Party  may
     determine. Secured Party may be a purchaser of the Collateral at any public
     sale.  Secured  Party will give  Debtor  reasonable  notice of the time and
     place of any public  sale  thereof or of the time after  which any  private
     sale or any other  intended  disposition  thereof  is to be made,  and such
     notice,  if given to the Debtor  pursuant to the  provisions of Paragraph 6
     hereof at least  twenty  (20) days prior to the date of any public  sale or
     disposition  or the date after which any private  sale or  disposition  may
     occur,   shall  constitute   reasonable   notice  of  such  sale  or  other
     disposition; and

          (c)  Exercise  any  remedies  of a Secured  Party  under  the  Uniform
     Commercial Code or any other applicable law.

     Debtor  hereby  agrees to  indemnity,  defend,  protect  and hold  harmless
Secured Party and its employees, officers and agents from and against an and all
damages, liabilities,  claims and obligations which may be incurred, asserted or
imposed upon them or any of them as a result of or in  connection  with any use,
operation,  or  consumption  of any of the  Collateral or as a result of Secured
Party's seeking to obtain performance of any of the obligations due with respect
to the Collateral, except from such damages, liabilities,  claims or obligations
as result from gross negligence or intentional  misconduct of Secured Party, its
employees, officers or agents.


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<PAGE>

     The proceeds of any sale under this  Paragraph 5 shall be applied  first to
the payment of any sums owing to Secured Party pursuant to the provisions of the
Note,  this Agreement in such manner as Secured Party may elect,  with any funds
remaining after payment of the foregoing to be paid to Debtor

     Secured  Party  shall  have  the  right  to  enforce  one or more  remedies
hereunder,  successively or  concurrently,  and such action shall not operate to
estop or prevent  Secured  Party from  pursuing any further  remedy which it may
have, and any repossession or retaking or sale of the Collateral pursuant to the
terms  hereof  shall not  operate to release  Debtor  until full  payment of any
deficiency has been made in cash.

     6. Notices.

     Any notice, demand or other communication which any party hereto may desire
or may be required to give to any other party shall be in writing,  and shall be
deemed given' if and when  personally  delivered,  or on the second business day
after being  deposited in United States  registered or certified  mail,  postage
prepaid,  addressed to a party at its address set forth below,  or to such other
address as such party may have designated to all other parties by written notice
in accordance herewith:

          If to Secured Party:

                                   Michael Pellegrino, Chief Financial Officer
                                   Digital Descriptor Systems, Inc.
                                   2010-F Cabot Blvd. West
                                   Langhorne, PA 19047

          If to Debtor:

                                   Garrett U. Cohn
                                   177 Ash Way
                                   Doylestown, PA 18901

Except as otherwise  specifically required herein, notice of the exercise of any
right,  option or power  granted  to  Secured  Party by this  Assignment  is not
required to be given.

     7. Waiver.

     By  exercising  or  failing  to  exercise  any of its  rights,  options  or
elections hereunder, Secured Party shall not be deemed to have waived any breach
or  default  on the part of Debtor or to have  released  Debtor  from any of its
obligations hereunder, unless such waiver or release is in writing and signed by
Secured Party. In addition,  the waiver by Secured Party of any breach hereof or
default in payment of any amounts due under the Note or this Agreement shall not
be deemed to constitute a waiver of any succeeding breach or default.

     8. Binding Agreement.

     This Agreement and all provisions hereof shall be binding upon Debtor,  its
successors, assigns, executors, administrators and legal representatives and all
other  persons  or  entities  claiming  under or  through  Debtor,  and the word
"Debtor,"  when used herein,  shall include all such persons or entities and any
others  liable for the payment of the  indebtedness  secured  hereby or any part
thereof,  whether or not they have executed the Note or this Agreement. The word
"Secured Party," when used herein, shall include Secured


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<PAGE>

Party's  successors,  assigns,  and legal  representatives,  including all other
holders, from time to time, of the Note.

     9. Governing Law; Interpretation.

     This Security Agreement shall be governed by the laws of the State the Note
and this Security  Agreement  were executed and  delivered,  the proceeds of the
Loan were  disbursed by Secured  Party and the  principal and interest due under
the Note are to be paid.  Wherever  possible  each  provision  of this  Security
Agreement  shall be  interpreted  in such a manner as to be effective  and valid
under  applicable law, but if any provision of this Security  Agreement shall be
prohibited by or invalid under such law, such provision  shall be ineffective to
the extent of such prohibition or invalidity, without invalidating the remainder
of such provision or the remaining  provisions of this Security Agreement.  Time
is of the essence in this Security Agreement.

     10. Miscellaneous.

     Neither  this  Security  Agreement  nor any  provision  hereof may amended,
modified,  waived,  discharged  or terminated  nor may any of the  Collateral be
released,  except by an  instrument  in writing  duly  signed by or on behalf of
Secured Party hereunder. The Section headings are used herein for convenience of
reference  only and shall not define or limit the  provisions  of this  Security
Agreement.  As used in this Security  Agreement,  the singular shall include the
plural, and the plural shall include the singular, and masculine,  feminine, and
neuter pronouns shall be fully interchangeable, where the context so requires.

     IN WITNESS  WHEREOF,  the parties  hereto have caused this  Agreement to be
executed by their  respective  officers  thereunto duly authorized as of the day
and year first above written.

DEBTOR:                                SECURED PARTY:
                                       DIGITAL DESCRIPTOR SYSTEMS, INC.

/s/ Garrett U. Cohn
-----------------------
GARRETT U. COHN               By: /s/ Michael Pellegrino
                                  --------------------------------
                                     Michael Pellegrino, Chief Financial Officer


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<PAGE>

                                    EXHIBIT A

DEBTOR:                       GARRETT U. COHN

SECURED PARTY:                DIGITAL DESCRIPTOR SYSTEMS, INC.

                              DESCRIPTION OF COLLATERAL


<PAGE>

                             SECURED PROMISSORY NOTE

$125,000.00                                                As of August 14, 1996
                                                         Langhorne, Pennsylvania

     FOR VALUE RECEIVED, GARRETT U. COHN ("Borrower"), hereby promises to pay to
the order of DIGITAL DESCRIPTOR  SYSTEMS,  INC. (the "Lender"),  at the Lender's
principal place of business in Langhorne,  Pennsylvania the principal sum of One
Hundred Twenty-Five Thousand and No/100 Dollars  ($125,000.00),  in lawful money
of the United States of America,  together with all accrued and unpaid interest,
on August 13, 1999.

     This  Secured  Promissory  Note (the  "Note")  shall bear  interest  on the
outstanding principal balance from the date of this Note on the unpaid principal
balance  outstanding from time to time at the annual rate of one percent (1%) in
excess of the rate of interest  announced or published  from time to time by The
Wall Street Journal as the prime or equivalent  rate of interest (such announced
or published rate of interest referred to as the "Prime Rate").

     Interest  shall accrue from even date herewith  until this Note is paid, at
which time all such accrued  interest shall be due and payable together with the
principal due hereunder.

     Interest  hereunder  shall be computed on the basis of actual days  elapsed
based upon a three  hundred  sixty (360) day year.  The  interest  rate shall be
adjusted in an amount equal to any increase or decrease in the Prime Rate on the
date of such adjustment.  It is expressly agreed that the use of the term "Prime
Rate"  is not  intended  nor does it  imply  that  said  rate of  interest  is a
preferred  rate of  interest  or one which is offered  to the most  creditworthy
customers of any bank or financial institution.

     This Note (this  "Note") is in  replacement  of and  substitution  for that
certain  Demand  Note  dated  August  14,  1996  in  the  principal   amount  of
$148,000.00, between Borrower and the Lender.

     1.  Prepayment.  This Note may be prepaid in whole or part, at any time and
from time to time without premium or penalty.

     2. Acceleration on Default;  Waivers. If any payment due under this Note or
any other monies owing  hereunder  is not paid when due,  then all  indebtedness
evidenced  by this Note,  will be due and payable in full at the election of the
Lender.  The  acceptance by Lender of any payment,  partial or  otherwise,  made
after the time when it becomes due will not  establish a custom or  constitute a
waiver by Lender of any right to enforce prompt  payment  thereof or a waiver of
any other  default  or the same  default  on  another  occasion.  TO THE  EXTENT
PERMITTED BY APPLICABLE  LAW,  BORROWER  HEREBY WAIVES DEMAND,  PRESENTMENT  FOR
PAYMENT, PROTEST AND NOTICE OF NON-PAYMENT AND PROTEST.

     3.  Fees,  Expenses  and Other  Charges.  If at any time or  times,  Lender
attempts to or enforces any of Lender's  rights and remedies  against  Borrower,
the reasonable costs and expenses  incurred by Lender in such enforcement  shall
be an  additional  liability,  payable by Borrower to Lender on demand.  Without
limiting the generality of the foregoing, such expenses, costs, charges and fees
include: (i) attorneys' fees, costs and expenses;  (ii) accountants' fees, costs
and expenses;  (iii) court costs and expenses;  (iv) court reporter fees,  costs
and expenses; (v) long distance telephone charges; and (vi) telegram,  telecopy,
facsimile, messenger and overnight courier charges.


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     4. Amendments and Modifications.  This Note may not be amended or modified,
nor shall any revision  hereof be effective,  except by an instrument in writing
expressing such intention executed by Lender and Borrower.

     5. Secured Note. This Note and the principal and interest due hereunder are
secured by a security agreement entered into as of even date herewith.

     6.  Choice  of Law.  This  Note  shall be  governed  and  controlled  as to
validity, enforcement, interpretation,  construction and effect by the statutes,
laws and decisions of the Commonwealth of Pennsylvania.

     IN WITNESS WHEREOF, the undersigned has executed and delivered this Note as
of the day and year first above written.



                                             /s/ Garrett U. Cohn
                                             --------------------------
                                              GARRETT U. COHN


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