Encryption key analysis method, encryption key analysis device and the encryption key analysis program

摘要

PROBLEM TO BE SOLVED: To reduce a calculation amount for determining a solution of an elliptic curve discrete logarithm problem.;SOLUTION: A cipher key analysis method 100 can reduce a range to be carried out an elliptic curve calculation by appling a self-isomorphic mapping to a part of the elliptic curve calculation when a table generation part 132 performs Baby-Step and Giant-Step to generate Tb table 141 and Tb table 142. As a result, a calculation amount for determining the elliptic curve discrete logarithm problem can be reduced to 1/(2 m)^1/2 compared with a conventional Cheon analysis method.;COPYRIGHT: (C)2012,JPO&INPIT