Patent ID: 6298153
Filing Date: 2001-10-02
Classification: G06F,H04L

Abstract:
A digital signature method including a public information generating step of generating public information specific to each user in accordance with a public parameter which satisfies a predetermined condition and is common to each user, and secret information specific to each user, a signature generating step of generating a signature of digital information by converting the digital information by using the secret information and the public parameter, and a signature discrimination step of verifying whether a relation between the digital information and the signature is correct, by using the public parameter and the public information, the digital signature method comprising:a user information generating step of generating new secret information specific to the user, a new parameter, and new public information by using the public information;a confirmation step of confirming whether or not the new secret information, new parameter, and new public information generated by said user information generating step satisfy a predetermined relation; andan enciphering step of enciphering digital information by using the new parameter and the new public information confirmed by said confirmation step.