Ethereum's design makes heavy use of Merkle trees enabling light clients to interact with the blockchain without having to download full blocks or its complete state.
Ethereum uses its own variant of Merkle trees, called Merkle Patricia Tries, which provide a dictionary-like interface and enable the generation and verification of small proofs (logarithmic in the number of items in the dictionary) that a given key-value-pair is present/absent from the dictionary. Ethereum uses Merkle Patricia Tries to store transactions, transactions receipts, and the state (all accounts with their balances, code, and storage).
(If you want to learn more about Merkle Patricia Tries, check out the links above and have a look at this cool visualisation Casey built.)
Proveth aims to provide
- a clearly specified format for these proofs;
- a high-quality off-chain proof generator that can connect to an Ethereum node and generate such proofs;
- a high-quality on-chain proof verifier (smart contract) that can verify a proof that a given transaction/state item/... is indeed part of the Ethereum blockchain.
Proveth is under active development. We currently support generating and verifying proofs of transaction inclusion/exclusion, i.e. proofs of statements of the form "the transaction tx was present/absent at index i in the block with blockhash h".
We aim to extend this to:
- proofs of transaction receipt inclusion/exclusion
- proofs about the Ethereum state
We welcome contributions. Have a look at any open issues, add more tests/documentation or come up with your own improvements. Before starting work on a large PR, we suggest opening an issue to discuss your approach with the maintainers.
We ❤️ tests & docs, so please write lots of them!
We follow PEP-8 for Python and the official style for Solidity.
Proveth's development was started by the Submarines group at the 2018 IC3 Ethereum bootcamp:
- Lorenz Breidenbach
- Tyler Kell
- Alex Manuskin
- Casey Detrio
- Derek Chin
- Shayan Eskandari
- Stephane Gosselin
- Yael Doweck
Our design is inspired by PeaceRelay. Thanks to Nate Rush for answering our questions.