Auditable Credential Anonymity Revocation Based on Privacy-Preserving Smart Contracts

TL;DR

This paper introduces a blockchain-based smart contract system for credential anonymity revocation that ensures auditability, availability, and efficiency through self-executing code and immutable ledgers.

Contribution

It presents a novel privacy-preserving smart contract framework for auditable credential anonymity revocation, including implementation and performance evaluation.

Findings

The scheme is feasible with acceptable running time.

Gas costs and latency are within practical limits.

The approach ensures auditability and availability of revocation processes.

Abstract

Anonymity revocation is an essential component of credential issuing systems since unconditional anonymity is incompatible with pursuing and sanctioning credential misuse. However, current anonymity revocation approaches have shortcomings with respect to the auditability of the revocation process. In this paper, we propose a novel anonymity revocation approach based on privacy-preserving blockchain-based smart contracts, where the code self-execution property ensures availability and public ledger immutability provides auditability. We describe an instantiation of this approach, provide an implementation thereof and conduct a series of evaluations in terms of running time, gas cost and latency. The results show that our scheme is feasible and efficient.