Flexible Anonymous Credentials from zk-SNARKs and Existing Identity Infrastructure

Principal Investigator: Christina Garman

Anonymous credentials provide a powerful tool for making assertions about identity while maintaining privacy.  While the subject of extensive academic work, anonymous credentials have thus far seen little deployment. In large part, this is because most existing systems are designed with a number of assumptions about identity that, in fact, are not actually true in practice, rendering them difficult to actually deploy. For example, existing systems assume that: there is a single issuer for a given identity property; there exist reputable authorities that are able (and more importantly willing) to be responsible for holding keys, verifying identity properties, and issuing credentials; all use cases and attributes needed for a credential are known in advance and are only simple statements ("my age is"); and the set of authorities for a given identity attribute or credential can be enumerated at the time we instantiate the system.

 

This work will explore expanding on prior work in decentralized anonymous credentials, where, using a decentralized ledger (like a blockchain) and standard cryptographic primitives, we built an anonymous credentials system that allows users to make flexible identity assertions with strong privacy guarantees.  Our aim is to now build a flexible, issuer-agnostic anonymous credential toolkit which allows for the representation of complex identity statements while still supporting the traditional properties afforded by previous anonymous credential systems. Additionally, the system will allow for widespread adoption by supporting the use of existing identity infrastructure (such as passports or drivers licenses) and enabling organizational agility, as both issuers and those accepting credentials do not need to work together to support new use cases.  We will also explore various real world applications of these credentials.

Personnel

Students: Jacob White