| 摘要 |
PROBLEM TO BE SOLVED: To trace an electronic money flow under reliable third person's supervison/permission when there is the possibility of money laundering or the like. SOLUTION: In the traceable electronic money execution method, a user US transmits the product N of prime numbers P, Q, a prime number L and a real name IDu to a bank BK, the bank BK generates an assumed name I corresponding the real name IDu, secretly manages correspondence relation between the names IDu, I, signs the values N, L, I based upon a signature function Ω=De B (N, L, I) and transmits the signed result Ω to the user as information including a use permit. The user US generates certification information X based upon the product N and a random number R, transmits information 2 obtained by applying blind signature preprocessing to (X, B) based upon a function Fe C and allows the bank BK to sign the Z by a signature function De C (Z) to obtain electronic money C. If electronic money is illegally used by a certain user, the bank BK opens the correspondence relation between the user's real name IDu and the assumed name I in accordance with an instruction from a court and traces the used electronic money. |
