Building a consumer scalable anonymity payment protocol for Internet purchases

The paper proposes a secure, scalable anonymity and practical payment protocol for Internet purchases. The protocol uses electronic cash for payment transactions. In this new protocol, from the viewpoint of banks, consumers can improve anonymity if they are worried about disclosure of their identities. An agent provides a higher anonymous certificate and improves the security of the consumers. The agent will certify re-encrypted data after verifying the validity of the content from consumers, but with no private information of the consumers required. With this new method, each consumer can get the required anonymity level, depending on the available time, computation and cost. We also analyse how to prevent a consumer from spending a coin more than once and how to use the proposed protocol for Internet purchases. After comparison with another scheme and discussing the properties of the new payment protocol, the new method is proved to be more efficient and can prevent eavesdropping, tampering and the "perfect crime" effectively. It is promising for electronic trade through the Internet.