Parity Shasper

This is an implementation of Serenity beacon chain by Parity Technologies. To learn more about Serenity and Ethereum's sharding plan, see the sharding FAQ and the research compendium.

Parity Shasper consists of a core library beacon which handles beacon chain state transition logic, a client built on Substrate framework (in substrate folder), and a lightweight client built from ground up (in blockchain folder). The substrate client and the blockchain client shares the core library, but operates independently.

To build the client, you need to have Rust installed. Other dependencies required including pkgconfig, libudev, openssl, cmake, clang.

substrate client

The substrate client uses LMD-GHOST consensus and Casper state transition with attestations based on a relatively old specification. The client also inherents the complete networking stack from Substrate. Note that it is an issue that we're addressing that this currently diverges a lot from the actual Serenity specification. If you are interested in following Serenity's newest specification development, it is recommended that you use the blockchain client in the next section.

To build the blockchain client, it is recommended that you use rustup as we need both stable and nightly Rust to build the project. In addition, you need to have wasm-gc installed for the WebAssembly runtime.

rustup update stable
rustup update nightly
rustup target add wasm32-unknown-unknown --toolchain nightly
cargo +nightly install --git https://github.com/alexcrichton/wasm-gc

To compile the WebAssembly runtime and run the client:

cd ./substrate && ./build.sh
cargo run --release -- --dev -k Alice

blockchain client

The blockchain client uses spec archive LMD-GHOST consensus and Serenity beacon v0.6 runtime. The client implements a basic in-memory backend and networking stack based on libp2p. It also contains basic validator logic and can participate in beacon chain proposing and attestation.

To build the blockchain client:

cd ./blockchain && cargo run --release -- --author

FAQ

Why common caching strategies for beacon and LMD-GHOST are not yet implemented?

Internally we made the decision that we will strictly follow the beacon chain specification for now, and implement optimizations after the specification is frozen. This is because the specification still changes a lot, and we worry that optimizations we make right now will make upgrading to a newer version of the specification much harder.

License

Licensed under GPLv3.