Blockchain from Scratch

PoW Blockchain implementation in Rust.

General idea was to fully understand technical blockchain mechanism by implementing one from scratch.

Description :

• main.rs : running basic tasks of the blockchain
• lib.rs : basic bytes functions needed in the program
• hashable.rs : computing data before hashing
• block.rs : main implementation, blockchain characteritics
• blockchain.rs : blockchain implentation and security mecanism defined in BlockValidationErr
• transactions.rs : transactions implementation based on UTXOs (Bitcoin based)

Installation

Install rust : https://www.rust-lang.org/

git clone https://github.com/ClementCauffet/Blockchain-from-Scratch.git
cd blockchain-from-scratch
cargo run

Mining strategy

1. Generate Nonce
2. Hash bytes (SHA-256)
3. Check against difficulty
   • Not enought -> back to 1.
   • Enought -> Move on to 4.
4. Add block to chain
5. Submit to peers

Adding blockcs Verification strategy

1. Actual index == stored index value
2. Correlation of the difficulty (just gonna trust difficulty atm -> dangerous for production applications)
3. Time continuously increasing
4. Actual previous block hash == stored prev_block_hash value (except genesis block)

Transactions verification strategy

1. Where did the money come from ?
2. Is the money available ?
3. Who owns the money and who is sending it ?
4. (WIP) more to cover later on cf -> https://en.bitcoin.it/wiki/Protocol_rules#.22tx.22_messages

Transactions definition

Transactions are composed of inputs and outputs. As a matter of fact, outputs are inputs from other transactions (UTXO-like).

Thanks to both Blockchain and Rust communities for information provided online :

Rust Language : https://www.rust-lang.org/

Algorithm Architecture : https://geeklaunch.net/blog/

!! This repository is still in progress. Do not use non-audited code for professionnal applications !!