Owners: @Antonio

In-depth page continuing from what was presented in https://www.notion.so/Preliminary-Sovereign-Zones-Research-1bb8f96fb65c803faee2d8ba9e5c7f51.

Polygon ZKEVM node repo has been discontinued and work merged into CDK Erigon repo.

The tech provides the following 1st class components:

• Sequencers: which execute transactions submitted by L2 users
• L1 smart contracts: to finalize transactions (docs mention it could use something else than Ethereum for DA) by verifying ZK proofs from the aggregator (presented in the next point)
• Aggregator: reads batches of unfinalized L2 transactions and sends them to the prover (presented in the next point) to generate a ZK proof of validity, which it then submits to the L1 smart contract
• Prover: receives batches of transactions and generates a ZK proof of validity

An architectural diagram can be found here: https://docs.polygon.technology/cdk/architecture/high-level-views/.

In Validium mode, only the hash of transaction data is published onto the L1, while the actual data is stored on a different DA solution.

Relevant repos:

• https://github.com/0xPolygon/cdk: CLI, sequencers, and aggregators
• https://github.com/0xPolygon/cdk-validium-node: Full node for L2s in Validium mode
• https://github.com/0xPolygon/cdk-data-availability: DA extension points
• https://github.com/0xPolygonHermez/zkevm-prover: ZKEVM prover (not available on Mac) - JS reference implementation: https://github.com/0xPolygonHermez/zkevm-proverjs (also not available on Mac)

Relevant interfaces exposed by the zkevm-prover binary

• (Stateless) executor service: Protobuf interface: executor.proto, C++ implementation: https://github.com/0xPolygonHermez/zkevm-prover/blob/d23715e37e1ceb048babd5a258147bb8f66ccc5e/src/service/executor/executor_service.cpp#L1716
• The only unsure bit is the “index of L1 info tree” and the l1_info_root parameters (https://github.com/0xPolygonHermez/zkevm-prover/blob/d23715e37e1ceb048babd5a258147bb8f66ccc5e/src/grpc/proto/executor.proto#L301)
  • The tree is explained here: https://docs.polygon.technology/zkEVM/architecture/high-level/smart-contracts/exit-roots/?h=l1+info+tree#l1-info-tree
  • They are used for bridging out of the L2 onto the L1, so they might not be relevant for our use case if we don’t want to showcase bridging from one L2 to another
  • It might be possible that these could be set to 0 when dealing with the prover in executor mode and not in aggregator mode, but this remains to be tested (relevant code lines dealing with this value: input.hpp)

Test deployment documentation: https://docs.polygon.technology/zkEVM/get-started/setup-nodes/deploy-zkevm/intro/.