Fair E-Payment Protocol Based on Certificateless Signature and Authenticated Key Exchange

摘要

E-payment protocol allows two or more users to securely exchange e-cash and digital product among them over an open network. There are some problems in the E-payment applications of cross-domain and cross-organization scenarios because of certificate-based authentication and digital signature, like inconsistent public key certificates and a heavy certificate management burden. ID-based cryptography is adopted to solve those problems, but it suffers the key escrow issue. Certificateless cryptography has been introduced to mitigate those limitations. A certificateless signature and authenticated key exchange scheme (CL-SAKE for short) is proposed, and its security is proved in the extended random oracle model. As an application, an E-payment protocol based on the new CL-SAKE is then proposed, which achieves unforgeability and un-reusability of e-cash, customer anonymity and fair exchange.