Zeromorph EvaluationEngine trait

[huitseeker]

• makes tests generic in the EvaluationEngine by adopting refactor: Parametrization of lib.rs tests for various EvaluationEngines #70,
• documents the gap between ZM / IPA: "endianness" w/ which coefficients must be supplied to the scheme,
• implements a CommitmentKey with a token universal setup, which allows implementing a CommitmentEngineTrait for KZG commitments,
• implements the prove & verify methods for the EvaluationEngineTrait implementation for ZMPCS. The scheme is slow (due to poor univariate KZG batching)

Closes #19

TODO:

• modify gen_srs_for_testing so the tests run in reasonable time.
• cleaning up "point endianness" a bit

Next steps:

• making univariate KZG actually fast,
• document the protocol a bit more ZeroMorph: Polish and document code #35,
• ZeroMorph: Initialize Fiat-Shamir in a secure way #22,

[storojs72]

Shouldn't we use pp-spartan by default in Arecibo, since we consider it more efficient and Ethereum-friendly than "regular" Spartan? At least I would propose mandatory having e2e proof/verify test instances in lib.rs for Bn256/Grumpkin curve cycle as we consider it as default in our solidity-verifier.

Trying to run test_ivc_nontrivial_with_compression with zeromorph stuff using pp-spartan, e.g.:

test_ivc_nontrivial_with_compression_with::<
      bn256::Point,
      grumpkin::Point,
      SPrime<bn256::Point, ZM<halo2curves::bn256::Bn256>>,
      SPrime<grumpkin::Point, EE<_>>,
    >();

gives me following assertion error (at setup phase):

thread 'tests::test_ivc_nontrivial_with_compression' panicked at 'assertion failed: ck.length() >= Self::commitment_key_floor()(S)', src/spartan/ppsnark.rs:912:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
test tests::test_ivc_nontrivial_with_compression ... FAILED

[huitseeker]

@storojs72 your point about the default doesn't really apply to Arecibo, since there isn't any "default" per se, Arecibo/Nova just provides the two APIs (compression, spark_compression) side-by-side. But it does apply to Lurk!

Trying to run test_ivc_nontrivial_with_compression with zeromorph stuff using pp-spartan, e.g.:

Yes, that's normal and due to microsoft/Nova#203, or #5 here. test_ivc_nontrivial_with_compression is meant to run with spartan but not computational commitment. The test you're looking for is test_ivc_nontrivial_with_spark_compression a few lines downstream. The reason it doesn't exhibit the same error is in the initialization of the public parameters.

[huitseeker]

This translates the former test_ivc_nontrivial_with_zm_compression

[mpenciak]

Looks great!