An E-Cash Based Implementation Model for Facilitating Anonymous Purchasing of Information Products

The rapid growing of online purchasing of information products poses challenges of how to preserve the customer's privacy during the online transactions. The current widely used way of online shopping does not consider the customer's privacy protection. It exposes the customer's sensitive information unnecessarily. We propose a new five-party implementation model called 5PAPS that provides much enhanced protection of the customer's privacy. The model combines the advantages of the e-cash techniques, the mix technique, the anonymous-honoring merchant model, and the anonymity-protecting payment gateway model. It is aimed for protecting the customer's anonymity in all applicable aspects. Security and anonymity issues of the model have been analyzed. The results show that the model is robust against varieties of common attacks and the customer's anonymity can be protected even in the presence of some collusion among the parties involved in the transactions. Experimental prototyping of the essential parts yields partial validation of the practical nature of the 5PAPS model, and it has also produced reliable estimates of the storage and messaging volume requirements present in sizable purchasing systems.