Signature system, signature method, proving apparatus, verification device, method of proof, verification method, program

摘要

PROBLEM TO BE SOLVED: To enable verification for legitimacy of signature and denial of forged signature with the identical procedure and also reduce the length of signature data.;SOLUTION: A first calculating section in a certifying apparatus generates a random number r to calculate X₁=g^r and transmits X₁ to a verifying apparatus. An element sharing section for certification in a certifying apparatus and an element sharing section for verification in a verifying apparatus share an element t of random G₂. A second calculating section in the certifying apparatus calculates X₂=e(h(m)^r, t) and transmits X₂ to the verifying apparatus. A random number generating section for verification in the verifying apparatus generates a random number c and transmits c to the certifying apparatus. A third calculating section in the certifying apparatus calculates =r+cx(mod v) and transmits to the verifying apparatus. A verifying section in the verifying apparatus verifies whether X₁y^c=g ^{and X₂e(s', t)c=e(h(m), t) are held.;COPYRIGHT: (C)2010,JPO&INPIT}