Enable Zerokit by default

[oskarth]

Problem

We want to use Zerokit by default to have one code base to worry about and pave the way to cross-client testnet.

Notes

Before this can happen, we need the following:

• Use Zerokit RLN module in nwaku #1030 or eqv merged.
  EDIT: merged Zerokit RLN integration in nwaku: alternative approach with inline compilation flag #1060
• Testnet1 complete Milestone: RLN-Relay testnet1 - dynamic group and on-chain vacp2p/research#126
• Implementation tested to ensure no major regressions found
• feat: Use zerokit by default/deploy on test fleet #1227

Acceptance criteria

• Zerokit enabled by default

We can either remove flag in PR that addresses this, or do this at a later stage (depends on confidence around perf etc)

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cc @s1fr0 @staheri14 just to capture this future work and its dependencies.

[s1fr0]

Integration will probably require revising/updating round constants of current smart contract Poseidon Hasher implementation so that result aligned with Circom zkSNARK Poseidon circuit.

@kgrgpg We might start working on a new rln-contract branch where the Circom constants are loaded in place of Kilic's ones and then check if the returned hashes correspond to the ones given by Circom implementation.

[staheri14]

@s1fr0 it would be very helpful to have an issue in https://github.com/vacp2p/rln-contract covering updates that are needed to be done on the contract, and with pointers to the relevant repos and files e.g., where the Circom constants reside, etc. Thanks!

[staheri14]

What is the state of this issue? I guess it needs some updates @s1fr0

[staheri14]

If zero-kit gets enabled by default, it will help resolving this issue as well #1213

[s1fr0]

Zerokit is enabled by default since release v.0.12. Kilic's library is still supported and can be enabled by passing KILICRLN=true instead of RLN=true (which now enables, instead, zerokit RLN).

Not sure what the second item refers to, since vacp2p/research#126 clearly states that zerokit integration is out of scope. Maybe a new testnet for nwaku with zerokit enabled? I would say that due to preparation of the live demo, all CC extensively tested (and bug-fixed) zerokit not only in nwaku but also in go-waku and js-waku so a preliminary testnet1 can be considered complete.

This issue was replaced by #1227 and hence can be closed.