|Title||Disposable dynamic accumulators: toward practical privacy-preserving mobile eIDs with scalable revocation|
|Publication Type||Journal Article|
|Year of Publication||2019|
|Authors||Hölzl, M., Roland M., Mir O., & Mayrhofer R.|
|Journal||International Journal of Information Security|
|Keywords||Electronic identities, mobile eID, privacy, requirements|
Providing methods to anonymously validate user identity is essential in many applications of electronic identity (eID) systems. A feasible approach to realize such a privacy-preserving eID is the usage of group signature protocols or pseudonym-based signatures. However, providing a revocation mechanism that preserves privacy is often the bottleneck for the scalability of such a system. In order to bridge this gap between practicability and privacy, we propose a new pseudonym-based mobile eID signature scheme suitable for smart cards and secure elements that also enables efficient and scalable revocation checks. By using a pseudorandom function, we derive one-time verification tokens used for identity verification as well as revocation checks and generate proofs of validity using a new method referred to as disposable dynamic accumulators. Our scheme preserves unlinkability and anonymity of the eID holder even beyond revocation and does not require online connectivity to a trusted party for verification and revocation checks.