关键词: 电子现金 可撤销匿名性 部分盲签名 知识证明的签名

Abstract:

Three key concepts, which conclude wallets with observers, partially blind signatures and a trusted third party （TTP）, have been proposed in order to attain a practical electronic cash （e-cash） system. In this paper, we incorporate the three primitives to propose an off-line e-cash system. The ban nk has to neither change his public key to represent a new expiration date, nor use different public keys for different coin values. The stress of storage is alleviated tremendously for the bank＇s only needs to store the valid records which are before their expiration dates. In contrast to the systems   which are based on Brands＂ scheme, the unforgeability of e-cash and the anonymity of legitimate users are provably secure. The security of our system    is based on random Oracle models and the intractability of the decision Diffie-Hellman oroblem.

Key words: （e-cash, anonymity revocation, partially blind signature, signature of proof of knowledge）