Provably Secure Off-Line E-Cash Scheme with Efficient Anonymity Revoking

Abstract

Due to the fast progress of the internet technologies, electronic commerce becomes more and more popular. Many people and businesses deal with their transactions via the internet. The technologies of credit cards, electronic tickets, electronic cash (e-cash), and other advanced services have realized the vision of electronic commerce. In this manuscript, we propose an offline e-cash scheme with anonymity, unlinkability, doublespending checking, and anonymity control. In an off-line e-cash scheme, the bank or the third party (TTP) must be able to revoke the anonymity of a user who doubly spent her/his e-cash(s). In our proposed e-cash scheme, the bank can fast derive the identity of the user who doubly spent her/his e-cash(s) without the participation of TTP. If some illegal transactions are reported, TTP can also directly revoke the anonymity of the user who spent her/his ecash( s) in the illegal transactions. In addition, the police need to trace a specific user in some situations. We also propose a mechanism to achieve this goal, call traceability.