Multi-authority anonymous authentication with public accountability for incentive-based applications.

Incentive-based applications enable users to obtain rewards after they complete a task, but how to balance the privacy and accountability is one of the most serious concerns currently. Publicly accountable anonymous authentication provides an excellent way verifying a user’s identity in a privacy-preserving way while ensuring public accountability in case of dispute. Although different kinds of these schemes have been proposed, they all assume that there is a single centralized certificate authority issuing a certificate to users, and are not suitable for an actual scenario which always involves multiple authorities. Therefore, a new primitive called multi-authority linkable and traceable anonymous authentication is proposed to address this issue, enabling privacy protection while holding public accountability under a multi-authority setting. We formally define a security model for this new notion and simultaneously design a generic construction while giving the security proof. Additionally, we implement the proposed scheme to show its efficiency.