Lighthouse: an Ethereum Serenity client

A work-in-progress, open-source implementation of the Serenity Beacon Chain, maintained by Sigma Prime.

The "Serenity" project is also known as "Ethereum 2.0" or "Shasper".

Lighthouse Client

Lighthouse is an open-source Ethereum Serenity client that is currently under development. Designed as a Serenity-only client, Lighthouse will not re-implement the existing proof-of-work protocol. Maintaining a forward-focus on Ethereum Serenity ensures that Lighthouse avoids reproducing the high-quality work already undertaken by existing projects. As such, Lighthouse will connect to existing clients, such as Geth or Parity-Ethereum, via RPC to enable present-Ethereum functionality.

Further Reading

• About Lighthouse: Goals, Ideology and Ethos surrounding this implementation.
• What is Ethereum Serenity: an introduction to Ethereum Serenity.

If you'd like some background on Sigma Prime, please see the Lighthouse Update #00 blog post or the company website.

Components

The following list describes some of the components actively under development by the team:

• BLS cryptography: Lighthouse presently use the Apache Milagro cryptography library to create and verify BLS aggregate signatures. BLS signatures are core to Serenity as they allow the signatures of many validators to be compressed into a constant 96 bytes and efficiently verified. The Lighthouse project is presently maintaining its own BLS aggregates library, gratefully forked from @lovesh.
• DoS-resistant block pre-processing: Processing blocks in proof-of-stake is more resource intensive than proof-of-work. As such, clients need to ensure that bad blocks can be rejected as efficiently as possible. At present, blocks having 10 million ETH staked can be processed in 0.006 seconds, and invalid blocks are rejected even more quickly. See issue #103 on ethereum/beacon_chain.
• P2P networking: Serenity will likely use the libp2p framework. Lighthouse is working alongside Parity to ensure libp2p-rust is fit-for-purpose.
• Validator duties : The project involves development of "validator services" for users who wish to stake ETH. To fulfill their duties, validators require a consistent view of the chain and the ability to vote upon blocks from both shard and beacon chains.
• New serialization formats: Lighthouse is working alongside researchers from the Ethereum Foundation to develop simpleserialize (SSZ), a purpose-built serialization format for sending information across a network. Check out the SSZ implementation and this research on serialization formats for more information.
• Fork-choice: The current fork choice rule is LMD Ghost, which effectively takes the latest messages and forms the canonical chain using the GHOST mechanism.
• Efficient state transition logic: State transition logic governs updates to the validator set as validators log in/out, penalizes/rewards validators, rotates validators across shards, and implements other core tasks.
• Fuzzing and testing environments: Implementation of lab environments with continuous integration (CI) workflows, providing automated security analysis.

In addition to these components we are also working on database schemas, RPC frameworks, specification development, database optimizations (e.g., bloom-filters), and tons of other interesting stuff (at least we think so).

Directory Structure

Here we provide an overview of the directory structure:

• beacon_chain/: contains logic derived directly from the specification. E.g., shuffling algorithms, state transition logic and structs, block validation, BLS crypto, etc.
• lighthouse/: contains logic specific to this client implementation. E.g., CLI parsing, RPC end-points, databases, etc.

Running

NOTE: The cryptography libraries used in this implementation are experimental. As such all cryptography is assumed to be insecure.

This code-base is still very much under-development and does not provide any user-facing functionality. For developers and researchers, there are several tests and benchmarks which may be of interest.

A few basic steps are needed to get set up:

1. Install rustup. It's a toolchain manager for Rust (Linux | macos | Windows). For installation run the below command in your terminal $ curl https://sh.rustup.rs -sSf | sh
2. (Linux & MacOS) To configure your current shell run: $ source $HOME/.cargo/env
3. Use the command rustup show to get information about the Rust installation. You should see that the active toolchain is the stable version.
4. Run rustc --version to check the installation and version of rust.
   • Updates can be performed using rustup update .
5. Install build dependencies (Arch packages are listed here, your distribution will likely be similar):
   • clang: required by RocksDB.
   • protobuf: required for protobuf serialization (gRPC).
6. Navigate to the working directory.
7. Run the test by using command cargo test --all. By running, it will pass all the required test cases. If you are doing it for the first time, then you can grab a coffee in the meantime. Usually, it takes time to build, compile and pass all test cases. If there is no error then it means everything is working properly and it's time to get your hands dirty. In case, if there is an error, then please raise the issue. We will help you.
8. As an alternative to, or instead of the above step, you may also run benchmarks by using the command cargo bench --all

Note:

Lighthouse presently runs on Rust stable, however, benchmarks currently require the nightly version.

Note for Windows users:

Perl may also be required to build lighthouse. You can install Strawberry Perl, or alternatively use a choco install command choco install strawberryperl.

Additionally, the dependency protoc-grpcio v0.3.1 is reported to have issues compiling in Windows. You can specify a known working version by editing version in protos/Cargo.toml's "build-dependencies" section to protoc-grpcio = "<=0.3.0".

Contributing

Lighthouse welcomes contributors with open-arms.

If you would like to learn more about Ethereum Serenity and/or Rust, we are more than happy to on-board you and assign you some tasks. We aim to be as accepting and understanding as possible; we are more than happy to up-skill contributors in exchange for their assistance with the project.

Alternatively, if you are an ETH/Rust veteran, we'd love your input. We're always looking for the best way to implement things and welcome all respectful criticisms.

If you are looking to contribute, please head to our onboarding documentation.

If you'd like to contribute, try having a look through the open issues (tip: look for the good first issue tag) and ping us on the gitter channel. We need your support!

Contact

The best place for discussion is the sigp/lighthouse gitter. Ping @paulhauner or @AgeManning to get the quickest response.

Donations

If you support the cause, we could certainly use donations to help fund development:

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