EXHIBIT 99.1 CERTIFICATION PURSUANT TO 18 U.S.C. Section 1350 Pursuant to 18 U.S.C. Section 1350, each of the undersigned certifies that this quarterly report on Form 10-Q for the period ended March 31, 2003 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in this Report fairly presents, in all material respects, the financial condition and results of operations of RSA Security Inc. and its wholly owned subsidiaries. /s/ ARTHUR W. COVIELLO, JR. ---------------------------------------------------- ARTHUR W. COVIELLO, JR. PRESIDENT AND CHIEF EXECUTIVE OFFICER Dated: May 12, 2003 /s/ JEFFREY D. GLIDDEN ---------------------------------------------------- JEFFREY D. GLIDDEN SENIOR VICE PRESIDENT, FINANCE AND OPERATIONS, CHIEF FINANCIAL OFFICER AND TREASURER Dated: May 12, 2003 The officers have provided to RSA Security a signed original of this written statement, as required by Section 906 of the Sarbanes-Oxley Act of 2002. RSA Security will retain the signed original and will furnish it to the Securities and Exchange Commission upon its request.