Complete credential circuit

[ed255]

I didn't add an ASCII diagram of the circuit as it would be quite large. Nevertheless I divided all the functionality into small components so that hopefully it can be easy to understand and reason about.

The credential circuit now allows the following:

• Proving ownership of a Holder identity (by proving knowledge of the private key in the kOP)
  • Using idOwnershipGenesis.circom
• Proving that a claim has been made to the Holder identity
• Proving that the claim was issued by an Issuer
• Proving that the claim has not been revoked in a recent Issuer Identity State
• Not revealing the Claim Tree Root in which the Issuer generated the Credential of Existence
  • This is done by proving that the Claim is in a Claim Tree Root which is in a Root of Roots which forms the recent Issuer Identity State.

The inputs have been generated with test/testvectorsgen/credential_test.go which depends on https://github.com/iden3/go-iden3-core/pull/374

[ed255]

@arnaucube I have kept the original code you wrote for credential (renamed it with old suffix). But maybe we can delete it?

[ed255]

I have added a new commit with

• Build instructions
• Script to build circuits + trusted setup
• credentialDemoWrapper.circom as a usage example of credential.circom