초록 ▼

In a method for implementing traceable electronic cash, a user US sends a bank BK a product N of prime numbers P and Q, a prime number L and his real name ID.sub.U, and the bank BK generates a pseudonym I corresponding to the real name ID.sub.U and keeps the correspondence between the real name ID.s

In a method for implementing traceable electronic cash, a user US sends a bank BK a product N of prime numbers P and Q, a prime number L and his real name ID.sub.U, and the bank BK generates a pseudonym I corresponding to the real name ID.sub.U and keeps the correspondence between the real name ID.sub.U and the pseudonym I secret. The bank BK uses a signature function .OMEGA.=D.sub.eB (N,L,I) to attach a signature to information composed of the above-mentioned N, L and I and sends the user US the signed information .OMEGA. as information containing a license B. The user US generates authentication information X from the N and a random number R and sends the bank BK information Z obtained by performing blind signature preprocessing on information (X,B) with a function F.sub.eC and has the information Z signed by the bank BK with a signature function D.sub.eC (Z) to obtain electronic cash C. When the user US abuses the electronic cash C, the bank BK follows a court order to reveal the correspondence between the real name ID.sub.U and pseudo name of the user US and trace the electronic cash spent.

대표청구항 ▼

[ What is claimed is:] [13.] An institution apparatus which issues a license and electronic cash in accordance with a method for implementing traceable electronic cash, said apparatus comprising:pseudonym generating means which receives from a user public information N and information containing the

[ What is claimed is:] [13.] An institution apparatus which issues a license and electronic cash in accordance with a method for implementing traceable electronic cash, said apparatus comprising:pseudonym generating means which receives from a user public information N and information containing the user's real name ID.sub.U and generates a pseudonym I corresponding to said real name ID.sub.U ;correspondence storage means which holds a table representing a correspondence between said real name ID.sub.U and at least one of said pseudonym I and said public information N;license signing means which uses a secret key for a license to sign, with a first signing function D.sub.eB, information containing said public information and said pseudonym I and sends said user the signed information as information containing a license B; andelectronic cash signing means which signs, with a second signing function D.sub.eC, said information received from said user and containing said license B and sends said user said signed information as electronic cash information.