Programmed computer for identity verification, forming joint signatures and session key agreement in an RSA public cryptosystem

摘要

An article of manufacture for improving an RSA cryptosystem, includes computer readable storage medium with computer programming stored thereon. The stored computer programming is configured to be readable from the computer readable storage medium by a computer and thereby cause the computer to operate so as to generate a private exponent key, having an associated modulus N of a predetermined bit length and a bit length of no greater than fifteen percent of the bit length of the associated modulus N but not less than 56 bits, and a corresponding public exponent key, to divide the private exponent key into a first private key portion and a second private key portion, to direct said first private key portion to a first user, and to direct the second private key portion to one or more other users of the RSA system.