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                                                                   EXHIBIT 10.55


                                    EXHIBIT C

                                    TERM NOTE



                                                              Irvine, California
$6,000,000.00                                                       July 7, 2000


         FOR VALUE RECEIVED, the undersigned DATUM INC., a Delaware corporation
("Borrower") promises to pay to the order of WELLS FARGO BANK, NATIONAL
ASSOCIATION ("Bank") at its office at Orange Coast Regional Commercial Banking
Office, 2030 Main Street, Suite 900, Irvine, California 92614, or at such other
place as the holder hereof may designate, in lawful money of the United States
of America and in immediately available funds, the principal sum of Six Million
Dollars ($6,000,000.00), with interest thereon as set forth herein.

INTEREST:

         1. Interest. The outstanding principal balance of this Note shall bear
interest at nine and three-twentieths percent (9.15%) per annum (computed on the
basis of a 360-day year, actual days elapsed).

         2. Payment of Interest. Interest accrued on this Note shall be payable
on the first day of each month, commencing July 1, 2000.

         3. Default Rate. From and after the maturity date of this Note, or such
earlier date as all principal owing hereunder becomes due and payable by
acceleration or otherwise, the outstanding principal balance of this Note shall
bear interest until paid in full at an increased rate per annum (computed on the
basis of a 360-day year, actual days elapsed) equal to four percent (4%) above
the rate of interest from time to time applicable to this Note.

REPAYMENT AND PREPAYMENT:

         4. Repayment. Principal shall be payable on the first day of each month
in installments of Two Hundred Fifty Thousand Dollars ($250,000.00) each,
commencing August 1, 2000, and continuing up to and including June 1, 2002, with
a final installment consisting of all remaining unpaid principal due and payable
in full on June 15, 2002.

         5. Application of Payments. Each payment made on this Note shall be
credited first, to any interest then due and second, to the outstanding
principal balance hereof.

         6. Prepayment. Borrower may prepay principal on this Note in the
minimum amount of Two Hundred Fifty Thousand Dollars ($250,000.00); provided
however, that if the outstanding principal balance of this Note is less than
said amount, the minimum prepayment amount shall be the entire outstanding
principal balance hereof. In consideration of Bank providing this prepayment
option to Borrower, or if this Note shall become due and payable at any time
prior to the maturity date hereof by acceleration or otherwise, Borrower shall
pay to Bank immediately upon demand a fee which is the sum of the discounted
monthly differences

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for each month from the month of prepayment through the month in which said
maturity date occurs, calculated as follows for each such month:

                  7. Determine the amount of interest which would have accrued
         each month on the amount prepaid at the interest rate applicable to
         such amount had it remained outstanding until the maturity date hereof.

                  8. Subtract from the amount determined in (i) above the amount
         of interest which would have accrued for the same month on the amount
         prepaid for the remaining term until the maturity date hereof at the
         Treasury Rate in effect on the date of prepayment for new loans made
         for such term and in a principal amount equal to the amount prepaid.

                  9. If the result obtained in (ii) for any month is greater
         than zero, discount that difference by the Treasury Rate used in (ii)
         above.

Borrower acknowledges that prepayment of such amount may result in Bank
incurring additional costs, expenses and/or liabilities, and that it is
difficult to ascertain the full extent of such costs, expenses and/or
liabilities. Borrower, therefore, agrees to pay the above-described prepayment
fee and agrees that said amount represents a reasonable estimate of the
prepayment costs, expenses and/or liabilities of Bank. If Borrower fails to pay
any prepayment fee when due, the amount of such prepayment fee shall thereafter
bear interest until paid at a rate per annum four percent (4.00%) above the
Prime Rate in effect from time to time (computed on the basis of a 360-day year,
actual days elapsed). The "Prime Rate" is a base rate that Bank from time to
time establishes and which serves as the basis upon which effective rates of
interest are calculated for those loans making reference thereto. Each change in
the rate of interest on any such past due prepayment fee shall become effective
on the date each Prime Rate change is announced within Bank.

         The "Treasury Rate" means the yield to maturity at the asked price of
the applicable obligation of the United States Treasury, with the applicable
obligation determined by Bank to be the Treasury obligation that will mature on
the maturity date of this Note (or the next day thereafter for which an asked
price is readily quoted in the public securities market), with the understanding
that such rate serves as the basis upon which effective rates of interest are
calculated for those loans making reference thereto, and is evidenced by the
recording thereof after its announcement in such internal publication or
publications as Bank may designate.

         All prepayments of principal shall be applied on the most remote
principal installment or installments then unpaid.

EVENTS OF DEFAULT:

         This Note is made pursuant to and is subject to the terms and
conditions of that certain Second Amended and Restated Credit Agreement between
Borrower and Bank dated as of July 7, 2000, as amended from time to time (the
"Credit Agreement"). Any default in the payment or performance of any obligation
under this Note, or any defined event of default under the Credit Agreement,
shall constitute an "Event of Default" under this Note.


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MISCELLANEOUS:

         10. Remedies. Upon the sale, transfer, hypothecation, assignment or
other encumbrance, whether voluntary, involuntary or by operation of law, of all
or any interest in any real property securing this Note, or upon the occurrence
of any Event of Default, the holder of this Note, at the holder's option, may
declare all sums of principal and interest outstanding hereunder to be
immediately due and payable without presentment, demand, notice of
nonperformance, notice of protest, protest or notice of dishonor, all of which
are expressly waived by Borrower. Borrower shall pay to the holder immediately
upon demand the full amount of all payments, advances, charges, costs and
expenses, including reasonable attorneys' fees (to include outside counsel fees
and all allocated costs of the holder's in-house counsel), expended or incurred
by the holder in connection with the enforcement of the holder's rights and/or
the collection of any amounts which become due to the holder under this Note,
and the prosecution or defense of any action in any way related to this Note,
including without limitation, any action for declaratory relief, whether
incurred at the trial or appellate level, in an arbitration proceeding or
otherwise, and including any of the foregoing incurred in connection with any
bankruptcy proceeding (including without limitation, any adversary proceeding,
contested matter or motion brought by Bank or any other person) relating to
Borrower or any other person or entity.

         11. Obligations Joint and Several. Should more than one person or
entity sign this Note as a Borrower, the obligations of each such Borrower shall
be joint and several.

         12. Governing Law. This Note shall be governed by and construed in
accordance with the laws of the State of California.


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


                                             DATUM INC.,
                                             a Delaware corporation


                                             By: /s/ David A. Young
                                                 -------------------------------
                                                 Name: David A. Young
                                                 Title: Chief Financial Officer


                                             By: /s/ Erik H. van der Kaay
                                                 -------------------------------
                                                 Name: Erik H. van der Kaay
                                                 Title: Chairman and CEO



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