AUTHENTICATION SYSTEM, SIGNATURE CREATING DEVICE, AND SIGNATURE VERIFYING DEVICE

摘要

A signature creating device for creating digital signature data fro certifying the accuracy of information on a person while making the information vague. The device is characterized by comprising storage means storing attribute information on a person and a secret key corresponding to the attribute information, vague information creating means for selecting one or more pieces of dummy information relevant to the attribute information and creating vague information including the attribute information and the one or more pieces of the dummy information, a public key acquiring means for acquiring the public key corresponding to the attribute information and the public keys corresponding to the one or more respective pieces of the dummy information, and signature creating means for adding a ring signature to the vague information by using the secret key and the public key corresponding to the attribute information and the public keys corresponding to the one or more respective pieces of the dummy information and creating digital signature data.