Privacy protecting digital payment system using ID-based blind signatures with anonymity revocation trustees

In this paper, a new digital payment system based on an ID-based blind signature scheme is presented. Blind signatures represent one cryptographic primitive tailored for applications where anonymity of the participants is an important requirement for instance in electronic commerce, in particular for payment systems. Since anonymity could be in conflict with law enforcement, for instance in cases of black mailing or money laundering, it has been proposed in literature to design systems in which a trustee or a set of trustees can selectively revoke the anonymity of the participants involved in a suspicious transaction. The trustee in the proposed payment system is only invoked in case of disputes and does not get involved in neither opening accounts nor issuing digital coins.