A User Efficient Fair E-cash Scheme with Anonymous Certificates

E-cash is considered as one of the coming mainstreams of digital currency due to its excellent security properties. With its perfect anonymity, however, e-cash may be misused to commit crimes. In this paper, we propose a fair e-cash scheme, which improves the previous schemes by reducing the computational and storage overhead of the trusted third party. In addition, our proposed scheme also possesses the desired user efficient property where a customer only has to compute several modular multiplication and addition in coin withdrawing. Due to the rapidly growing of the Internet access via mobile units with low computation power, the user efficient property is of great worth. Thus this work can provide an efficient and practical payment mechanism for electronic commerce.