Commitment system, common reference information generating apparatus, commit generating device, commit the receiving device, commitment method, and program

摘要

PROBLEM TO BE SOLVED: To shorten a common reference string in a CRS-reusable, noninteractive, information-revocation-saving efficient universally composable commitment.;SOLUTION: A common reference string generation apparatus 2 generates a public key pk and a secret key sk, revokes the secret key sk and discloses the public key pk. A commitment generation apparatus 3 generates a random number r and a sample value u, encrypts a plaintext m with the public key pk, the random number r, a tag t and the sample value u to generate a ciphertext c, sends the ciphertext c, the tag t and the sample value u to a commitment reception apparatus 4, and sends the plaintext m and the random number r to the commitment reception apparatus 4. The commitment reception apparatus 4 encrypts the plaintext m with the public key pk, the random number r, the tag t and the sample value u to produce a ciphertext c', and verifies that the ciphertext c' is the same as the ciphertext c.;COPYRIGHT: (C)2014,JPO&INPIT