Authentication system, signature creating device, and signature verifying device

摘要

A signature generating device generating digital signature data for certifying authenticity of information of a person, and obfuscating the information. The signature generating device includes a storage unit storing attribute information concerning the person and a private key corresponding to the attribute information, an obfuscated information generating unit selecting one or more pieces of dummy information in relation to the attribute information, and generating the obfuscated information including the attribute information and the dummy information; and a public key obtaining unit obtaining a public key corresponding to the attribute information and public keys respectively corresponding to the dummy information. The signature generating device also includes a signature generating unit generating digital signature data by performing a ring signature generation process to the obfuscated information, using the private key and the public key corresponding to the attribute information and using the public keys corresponding to dummy information.