Polygon zkEVM

Polygon zkEVM utilizes PIL-STARK as the main proving stack for their system. PIL-STARK is an implementation of the eSTARK protocol designed specifically to prove PIL specifications. eSTARK extends the STARK proof system to support eAIR, an intermediate representation that allows to succinctly express non-equality constraints. The circuits and the computations are represented using the PIL and zkASM custom languages. The scheme makes use of the Goldilocks field, which is much smaller than alt_bn128’s field.

The protocol makes use of recursive proof aggregation. Extensive documentation can be found here. The system doesn’t implement transaction data compression yet.

The final proof is wrapped into a fflonk proof. The CRS used is the powersOfTau28_hez_final that can be found here. The instructions to regenerate the verification keys can be found here.

The differences between the zkEVM and the EVM are listed here. The source code of the zkEVM can be found here.