AUTHENTICATION SYSTEM, SIGNATURE CREATING DEVICE, AND SIGNATURE VERIFYING DEVICE

摘要

A signature generating device for generating digital signature data that certifies authenticity of information of a person, and making the information obfuscated. The signature generating device comprises: a storage unit that stores attribute information concerning the person and a private key corresponding to the attribute information; an obfuscated information generating unit that selects one or more pieces of dummy information in relation to the attribute information, and generates the obfuscated information that includes the attribute information and the dummy information; a public key obtaining unit that obtains a public key corresponding to the attribute information and public keys respectively corresponding to the dummy information; and a signature generating unit that generates 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.