<ARTICLE> 5 <CIK> 0000932064 <NAME> SECURITY DYNAMICS TECHNOLOGIES, INC. <MULTIPLIER> 1,000 <CURRENCY> U.S. DOLLARS <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1996 <PERIOD-START> JAN-01-1996 <PERIOD-END> SEP-30-1996 <EXCHANGE-RATE> 1 <CASH> 7,332 <SECURITIES> 96,043 <RECEIVABLES> 12,760 <ALLOWANCES> 488 <INVENTORY> 2,717 <CURRENT-ASSETS> 120,597 <PP&E> 11,353 <DEPRECIATION> 2,908 <TOTAL-ASSETS> 132,064 <CURRENT-LIABILITIES> 19,888 <BONDS> 0 <COMMON> 342 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <OTHER-SE> 95,995 <TOTAL-LIABILITY-AND-EQUITY> 112,118 <SALES> 52,645 <TOTAL-REVENUES> 52,645 <CGS> 12,261 <TOTAL-COSTS> 48,667 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 104 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 12,134 <INCOME-TAX> 6,530 <INCOME-CONTINUING> 12,134 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 12,134 <EPS-PRIMARY> 0.15 <EPS-DILUTED> 0.15