IBC Eureka in Solidity

This is a work-in-progress IBC Eureka implementation in Solidity. IBC Eureka is a simplified version of the IBC protocol that is encoding agnostic. This project also includes an SP1 based tendermint light client for the Ethereum chain, and a POC relayer implementation.

Overview

solidity-ibc-eureka is an implementation of IBC in Solidity.

Project Structure

This project is structered as a foundry project with the following directories:

• contracts/: Contains the Solidity contracts.
• test/: Contains the Solidity tests.
• scripts/: Contains the Solidity scripts.
• abi/: Contains the ABIs of the contracts needed for end-to-end tests.
• abigen/: Contains the abi generated go files for the Solidity contracts.
• e2e/: Contains the end-to-end tests, powered by interchaintest.
• programs/: Contains the Rust programs for the project.
  • relayer/: Contains the relayer implementation.
  • operator/: Contains the operator for the SP1 light client.
  • sp1-programs/: Contains the SP1 programs for the light client.
  • cw-ics08-wasm-eth/: Contains the (WIP) CosmWasm 08-wasm light client for Ethereum
• packages/: Contains the Rust packages for the project.

Contracts

Contracts	Description	Status
ICS26Router.sol	IBC Eureka router handles sequencing, replay protection, and timeout checks. Passes proofs to ICS02Client.sol for verification, and resolves portId for app callbacks. Provable IBC storage is stored in this contract.	✅
ICS02Client.sol	IBC Eureka light client router resolves clientId for proof verification. It also stores the counterparty information for each client.	✅
ICS20Transfer.sol	IBC Eureka transfer application to send and receive tokens to/from another Eureka transfer implementation.	✅
SP1ICS07Tendermint.sol	The light client contract, and the entry point for SP1 proofs.	✅
ICS27Controller.sol	IBC Eureka interchain accounts controller.	❌
ICS27Host.sol	IBC Eureka interchain accounts host.	❌

SP1 Programs for the Light Client

Programs	Description	Status
update-client	Once the initial client state and consensus state are submitted, future consensus states can be added to the client by submitting IBC Headers. These headers contain all necessary information to run the Comet BFT Light Client protocol. Also supports partial misbehavior check.	✅
membership	As consensus states are added to the client, they can be used for proof verification by relayers wishing to prove packet flow messages against a particular height on the counterparty. This uses the verify_membership and verify_non_membership methods on the tendermint client.	✅
uc-and-membership	This is a program that combines update-client and membership to update the client, and prove membership of packet flow messages against the new consensus state.	✅
misbehaviour	In case, the malicious subset of the validators exceeds the trust level of the client; then the client can be deceived into accepting invalid blocks and the connection is no longer secure. The tendermint client has some mitigations in place to prevent this.	✅

Requirements

• Rust
• Foundry
• Bun
• Just
• SP1 (for end-to-end tests)

Foundry typically uses git submodules to manage contract dependencies, but this repository uses Node.js packages (via Bun) because submodules don't scale. You can install the contracts dependencies by running the following command:

bun install

You also need to have the operator and relayer binaries installed on your machine to run some of the end-to-end tests. You can install them by running the following commands:

just install-operator
just install-relayer

Tip

Nix users can enter a development shell with all the necessary dependencies by running:

nix develop

Unit Testing

There are multiple unit tests for the solidity contracts located in the test/ directory. The tests are written in Solidity using foundry/forge.

To run all the tests, run the following command:

just test-foundry

The recipe also accepts a testname argument that will only run the test with the given name. For example:

just test-foundry test_success_sendTransfer

End to End Testing

There are several end-to-end tests in the e2e/interchaintestv8 directory. These tests are written in Go and use the interchaintest library. It spins up a local Ethereum and a Tendermint network and runs the tests found in e2e/interchaintestv8/ibc_eureka_test.go. Some of the tests use the prover network to generate the proofs, so you need to provide your SP1 network private key to .env for these tests to pass.

To prepare for running the e2e tests, you need to make sure you have done the following:

• Installed the sp1-ics07-tendermint operator binary (see instructions above)
• Set up an .env file (see the instructions in the .env.example file)
• If you have made changes to the contract interfaces or types, you need to update the ABIs by running just generate-abi

Note

If you are running on a Mac with an M chip, you will need to do the following:

• Set up Rosetta

• Enable Rosetta for Docker (in Docker Desktop: Settings -> General -> enable "Use Rosetta for x86_64/amd64 emulation on Apple Silicon")

• Pull the foundry image with the following command:

  docker pull --platform=linux/amd64 ghcr.io/foundry-rs/foundry:latest

Running the tests

There are three test suites in the e2e/interchaintestv8 directory:

• TestWithIbcEurekaTestSuite: This test suite tests the IBC Eureka contracts via manual relaying (requires the operator to be installed).
  • To run any of the tests, run the following command:

    just test-e2e $TEST_NAME

• TestWithRelayerTestSuite: This test suite tests the IBC Eureka contracts via the relayer (requires the relayer and operator to be installed).
  • To run any of the tests, run the following command:

    just test-e2e-relayer $TEST_NAME

• TestWithSP1ICS07TendermintTestSuite: This test suite tests the SP1 ICS07 Tendermint light client (requires the operator to be installed).
  • To run any of the tests, run the following command:

    just test-e2e-sp1-ics07 $TEST_NAME

Where $TEST_NAME is the name of the test you want to run, for example:

just test-e2e TestDeploy_Groth16

Linting

Before committing, you should lint your code to ensure it follows the style guide. You can do this by running the following command:

just lint

End to End Benchmarks

The contracts in this repository are benchmarked end-to-end using foundry. The following benchmarks were ran with the underlying sp1-ics07-tendermint. About ~230,000 gas is used for each light client verification (groth16), and this is included in the gas costs below for recvPacket, timeoutPacket and ackPacket. At the time of writing, proof generation takes around 1 minute. More granular and in-depth benchmarks are planned for the future.

Single Packet Benchmarks

The following benchmarks are for a single packet transfer without aggregation.

Contract	Method	Description	Gas (groth16)	Gas (plonk)
ICS26Router.sol	sendPacket	Initiating an IBC transfer with an ERC20.	~186,808	~186,808
ICS26Router.sol	recvPacket	Receiving back an ERC20 token.	~541,800	~626,140
ICS26Router.sol	recvPacket	Receiving a new Cosmos token for the first time. (Deploying an ERC20 contract)	~1,436,748	~1,520,226
ICS26Router.sol	ackPacket	Acknowledging an ICS20 packet.	~419,121	~502,895
ICS26Router.sol	timeoutPacket	Timing out an ICS20 packet	~471,313	~554,696

Aggregated Packet Benchmarks

The gas costs are substantially lower when aggregating multiple packets into a single proof, as long as the packets are submitted in the same tx. Since there is no meaningful difference in gas costs between plonk and groth16 in the aggregated case, they are not separated in the table below.

ICS26Router Method	Description	Avg Gas (25 packets)	Avg Gas (50 packets)
multicall/recvPacket	Receiving back an ERC20 token.	~198,341	~191,618
multicall/ackPacket	Acknowledging an ICS20 packet.	~105,336	~99,365

Note: These gas benchmarks are with Groth16.

Run ICS-07 Tendermint Light Client End to End

1. Set the environment variables by filling in the .env file with the following:

   cp .env.example .env

   You need to fill in the PRIVATE_KEY, SP1_PROVER, TENDERMINT_RPC_URL, and RPC_URL. You also need the SP1_PRIVATE_KEY field if you are using the SP1 prover network.

2. Deploy the SP1ICS07Tendermint contract:

   just deploy-sp1-ics07

   This will generate the contracts/script/genesis.json file which contains the initialization parameters for the contract. And then deploy the contract using contracts/script/SP1ICS07Tendermint.s.sol. If you see the following error, add --legacy to the command in the justfile:

   Error: Failed to get EIP-1559 fees    
   

3. Your deployed contract address will be printed to the terminal.

   == Return ==
   0: address <CONTRACT_ADDRESS>
   

   This will be used when you run the operator in step 5. So add this to your .env file.

   CONTRACT_ADDRESS=<CONTRACT_ADDRESS>

4. Run the Tendermint operator.

   To run the operator, you need to select the prover type for SP1. This is set in the .env file with the SP1_PROVER value (network|local|mock). If you run the operator with the network prover, you need to provide your SP1 network private key with SP1_PRIVATE_KEY=0xyourprivatekey in .env.

   RUST_LOG=info cargo run --bin operator --release -- start

Etheruem Light Client

Caution

⚠ The Ethereum Light Client is currently under heavy development, and is not ready for use.

This repository contains an Ethereum light client which is implemented as two separate layers:

• A CosmWasm contract that supports the 08-wasm light client interface in programs/cw-ics08-wasm-eth
• A stateless light client verification package in packages/ethereum-light-client

License

This project is licensed under MIT.

Acknowledgements

This project was bootstrapped with this template. Implementations of IBC specifications in solidity, CosmWasm, golang, and rust were used as references. We are also grateful to unionlabs for their 08-wasm ethereum light client implementation for ibc-go which our own implementation is based on.