Transition to `arkworks`

[Pratyush]

Hi all!

Going forward, we're planning to deprecate zexe, and all development will instead happen in the arkworks-rs organization. As part of this plan, we're planning on moving this repository to arkworks-rs/snark.

While I've made a tagged release containing the latest version of the zexe, (so that users can pin their dependencies to it), I highly recommend upgrading to the equivalent arkworks dependencies, as only these will receive feature dev and bug fixes going forward. Indeed, the arkworks repos have already received some bug fixes that zexe has (and will) not, such as for #232, #300, #289, #286, #275, #220, #105. Below is a quick guide on how to update your dependencies:

• algebra-core:
  • fields/biginteger -> ark-ff
  • serialize -> ark-serialize
  • curves -> ark-ec
• algebra:
  • All curves have moved to individual crates in arkworks-rs/curves
  • These crates also include the constraints for relevant curves (like bls12-377)
• ff-fft -> ark-poly
  • The arkworks version is more general as it also contains support for multivariate polynomials.
• r1cs-core -> ark-snark/relations/r1cs
• r1cs-std -> ark-r1cs-std
• groth16 -> ark-groth16
  • This repo now additionally (optionally) contains implementations of the constraint system for the SNARK verifier.
• gm17 -> ark-gm17
  • This repo now additionally (optionally) contains implementations of the constraint system for the SNARK verifier.
• crypto-primitives -> ark-crypto-primitives
  • Note that the NIZK trait has been upgraded to a SNARK trait, and so has the corresponding Gadget trait.
• scipr-lab/poly-commit -> ark-poly-commit
  • An upcoming PR will add support for constraints for some PC schemes, which can be useful for verifying universal SNARKs or for verifying pairing-based accumulators.
• scipr-lab/marlin -> ark-marlin
  • An upcoming PR will add support for constraints for verifying a Marlin proof.

[Pratyush]

FYI @paberr @kobigurk @jon-chuang @brunoffranca @yelhousni

[Pratyush]

Also cc @schaeff, @dark64