A blind signature-based protocol for tracing traitors

Abstract

We introduce a protocol based on blind signatures using elliptic curves that allows to trace those users of any service, traitors, that share their legitimate license with other people, avoiding the abuse or the unauthorized use of legal licenses. We show that our protocol is incapable of implicating innocent users in the illegal distribution of licenses and that tracing produces indisputable proof for the implication of the traitors. We also show that our protocol provides anonymity to users unless they share their private information and compare it to other existing schemes. We also provide an implementation showing its practical application.