[Zero-knowledge Proof of Identity paper](https://eprint.iacr.org/2019/546.pdf)
 "turning X.509 certificates into anonymous credentials."


[business level description of zkSNARK](https://medium.com/@SamRadOfficial/why-zk-snarks-are-crucial-for-blockchain-data-privacy-e02f4bc1d352)
"zk-SNARK is a form of cryptography that proves possession of certain information without revealing that information, and without any interaction between the prover and verifier."


[Introduction to zk-SNARKs with Examples](https://media.consensys.net/introduction-to-zksnarks-with-examples-3283b554fc3b) 

It looks like the libraries available are still fairly early stage, but the excitement around it should make them move fairly fast

Open question - how can this be integrated into a universal-use protocol that may include participants that do not use zkSNARK - 
can we use it with different levels of uncertainty from different external providers who might identify people in looser ways?