sunsided / rustchain

A Rust blockchain playground

rustchain - a blockchain example in Rust

This repo is purely an exploration of current ideas communicated in various blog posts. It is not meant to produce a practically useful blockchain solution, nor does it attempt to be particularly smart about it. Most if not all credit goes to the authors of the posts below:

• How to build a blockchain in Rust by Mario Zupan
  • Proof-of-work mining
  • Data is purely in-memory, i.e. the blockchain is not persisted
  • Essentially builds upon libp2p, Tokio and sha2
  • GitHub repo at zupzup/rust-blockchain-example
• How to Build a Blockchain from Scratch with Rust Programming Language by Nandu Singh
• Rusty Chains: A Basic Blockchain Implementation Written in Pure Rust on hackernoon

Example

To run the example, execute

$ RUST_LOG=info cargo run

After the console output settles, you can execute these commands:

• ls p: prints all discovered peers
• ls c: prints the current blockchain
• create b <DATA>: creates (mines) a new block containing the payload <DATA>

Known flaws

• If two peers disagree on the next block in a chain because they are mining a successor block to the current state, the first one wins and the second one is now in a failed state from which it will not recover.
• Race conditions can be created by increasing the difficulty and creating a block on multiple application instances simultaneously.