| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital signature method which has a short signature length, has less computational complexity of verification relations and has high provable security for a group element message. SOLUTION: A signature device includes at least a signature recording part, a signature validation part, a signature random number producing part, a signature calculation part and a signature output part. A verification device includes a verification input part and a verification validation part. The signature validation part validates e(M<SB>1</SB>, g<SB>2</SB>)=e(g<SB>1</SB>, M<SB>2</SB>). The signature random number producing part produces a random integer r of 1 or more and q-1 or less. The signature calculation part calculates A<SB>1</SB>=g<SB>1</SB><SP>r</SP>, A<SB>2</SB>=M<SB>1</SB><SP>ry</SP>, B<SB>3</SB>=g<SB>2</SB><SP>rx</SP>M<SB>2</SB><SP>rxy</SP>and B<SB>4</SB>=g<SB>2</SB><SP>ry</SP>. The signature output part outputs (A<SB>1</SB>, A<SB>2</SB>, B<SB>3</SB>, B<SB>4</SB>). The verification validation part validates that A<SB>1</SB>and M<SB>1</SB>have dimensions other than 1 on a group G<SB>1</SB>, and e(M<SB>1</SB>, g<SB>2</SB>)=e(g<SB>1</SB>, M<SB>2</SB>), e(A<SB>1</SB>, Y<SB>2</SB>)=e(g<SB>1</SB>, B<SB>4</SB>), e(A<SB>2</SB>, g<SB>2</SB>)=e(M<SB>1</SB>, B<SB>4</SB>) and e(g<SB>1</SB>, B<SB>3</SB>)=e(A<SB>1</SB>A<SB>2</SB>, X<SB>2</SB>). COPYRIGHT: (C)2011,JPO&INPIT |
