<ARTICLE> 5 <CIK> 0000932064 <NAME> SECURITY DYNAMICS TECHNOLOGIES, INC. <MULTIPLIER> 1,000 <CURRENCY> U.S. DOLLARS <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> MAR-31-1997 <EXCHANGE-RATE> 1 <CASH> 14,310 <SECURITIES> 89,208 <RECEIVABLES> 14,139 <ALLOWANCES> 546 <INVENTORY> 2,798 <CURRENT-ASSETS> 125,573 <PP&E> 14,515 <DEPRECIATION> 3,981 <TOTAL-ASSETS> 140,577 <CURRENT-LIABILITIES> 12,744 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 350 <OTHER-SE> 125,797 <TOTAL-LIABILITY-AND-EQUITY> 140,577 <SALES> 26,436 <TOTAL-REVENUES> 26,436 <CGS> 6,041 <TOTAL-COSTS> 20,138 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 30 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 7,571 <INCOME-TAX> 2,842 <INCOME-CONTINUING> 4,729 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 4,729 <EPS-PRIMARY> 0.13 <EPS-DILUTED> 0.13 <FN> INCOME-PRETAX INCLUDES $1,273 INTEREST & OTHER INCOME TOTAL-LIABILITY-AND-EQUITY INCLUDES $1,686 MINORITY INTEREST.