Method and apparatus for implementing traceable electronic cash

摘要

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 &OHgr;=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 &OHgr; 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.