EXHIBIT 99.1 CERTIFICATION PURSUANT TO 18 U.S.C. 'SS' 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 Pursuant to 18 U.S.C. 'SS' 1350, each of the undersigned certifies that this Quarterly Report on Form 10-Q for the period ended September 30, 2002 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 DSET Corporation. DATE: November 14, 2002 By: /s/ Dr. Binay Sugla ------------------------------------- Dr. Binay Sugla, Chief Executive Officer DATE: November 14, 2002 By: /s/ Bruce M. Crowell ------------------------------------- Bruce M. Crowell Vice President and Chief Financial Officer