<ARTICLE> 5
<LEGEND>
This Schedule contains summary financial information extracted from the
Company's financial statements included in the Quarterly Report on Form 10-Q and
is qualified in its entirety by reference to such financial statements.
</LEGEND>
<CIK> 0000932064
<NAME> SECURITY DYNAMICS TECHNOLOGIES INC.
<MULTIPLIER> 1,000
<CURRENCY> U.S. DOLLARS
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-START>                             JAN-01-1996
<PERIOD-END>                               JUN-30-1996
<EXCHANGE-RATE>                                      1
<CASH>                                           5,639
<SECURITIES>                                    83,466
<RECEIVABLES>                                    9,241
<ALLOWANCES>                                       257
<INVENTORY>                                      2,365
<CURRENT-ASSETS>                               102,994
<PP&E>                                           5,633
<DEPRECIATION>                                   1,798
<TOTAL-ASSETS>                                 108,424
<CURRENT-LIABILITIES>                            7,477
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           137
<OTHER-SE>                                     100,810
<TOTAL-LIABILITY-AND-EQUITY>                   108,424
<SALES>                                         26,240
<TOTAL-REVENUES>                                26,240
<CGS>                                            6,172
<TOTAL-COSTS>                                   20,045
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                    72
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                  8,560
<INCOME-TAX>                                     3,124
<INCOME-CONTINUING>                              5,436
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     5,436
<EPS-PRIMARY>                                      .38
<EPS-DILUTED>                                      .38