A Fair Off-line E-Cash System with Group Signature

摘要

This paper describes the research results and development of fair off-line e-cash systems so far, and points out that in these systems, the bank can compute the double-spender's account secret key, thus the bank can impersonate the double-spender to withdraw from the double-spender' s account. This article utilizes anonymity control and group signature to address this shortcoming.