Kroma SP1 Prover

This project provides WitnessGenerator for users attempting to assert the validity of a specific block on Optimism.

Since the order of all transactions included in an Optimism block is finalized when they are uploaded to L1, verifying the validity of an L2 block starts with downloading the transactions it includes from L1 and then executing them. This procedure, known as the derivation process, utilizes the Kona implementation.

The witness refers to all the external data required during the execution of the derivation process. This witness can be passed to the zkvm-prover-proxy to generate the sp1 proof.

Run a Witness Generator

Environment Variables

The 4 RPC endpoints must be set to run WitnessGenerator. It is recommended to fill in the following environment variables in the .env file.

L1_RPC=
L1_BEACON_RPC=
L2_RPC=
L2_NODE_RPC=
MAX_BATCH_POST_DELAY_MIN=<Integer - According to the Sequencer's spec>
SKIP_SIMULATION=<Boolen - if `true`, it returns the generated witness without simulating it>

Run

> cargo run --bin witness-gen-server --release -- --endpoint <IP_WITH_PORT> --data <DB_PATH>

# example
> cargo run --bin witness-gen-server --release -- --endpoint 0.0.0.0:3030 --data /data/witness_store

API Overview

requestWitness method

Register a request to generate a witness.

{
    "jsonrpc": "2.0",
    "method": "requestWitness",
    "params": [<0xL2Hash>, <0xL1HeadHash>],
    "id": 0
}

getWitness method

It returns the witness after finishing to generate it.

{
    "jsonrpc": "2.0",
    "method": "getWitness",
    "params": [<0xL2Hash>, <0xL1HeadHash>],
    "id": 0
}

Integration Test

The test client requests generating Witness to the WitnessGenerator.

> just run-witness-scenario <0xL2Hash> <0xL1HeadHash>

Build Docker Images

Inject the .env file described above.

> make build-witness-generator
> docker build -f docker/Dockerfile.witnessgen.ubuntu -t witness-gen .
> docker run -itd --env-file .env -p 3030:3030 witness-gen

Useful scripts

Preview script

This script provides a general context corresponding to the specific l2 block in advance.

> cargo run --release --bin script -- --method preview --l2-block <L2Number>
# - output_root: <OutputRootAtTheL2Block>
# - parent_output_root: <OutputRootAtThePreviousL2Block>
# - l1_origin_hash: <L1OriginBlockHashOfTheL2Block>
# - l1_origin_number: <L1OriginBlockNumberOfTheL2Block>
# - l1_head_number: <L1OriginBlockNumberOfTheL2Block> + 300

Execute script

Execute the specific l2 block.

> cargo run --release --bin script -- --method execute --l2-block <L2Number> --l1-head-number <L2HeadNumber>

# Or
> cargo run --release --bin script -- --method execute --l2-block <L2Number> --l1-head-hash <L2HeadHash>