js-blockchain

Description

Proof of concept javascript blockchain with basic wallet and miner.

Disclaimer

This is simply a Proof of Concept implementation to familiarize myself with blockchains, it most likely is wrong in a lot of places, lacks any (thought of) any security features, and will most likely only serve well as an enjoyable reading excercise for bored peers.

Usage

Clone repository, install dependencies:

bash$ git clone git@github.com:allbinmani/js-blockchain.git
bash$ cd js-blockchain; npm i

Generate code for your own unique blockchain, with it's unique COINBASE1, GENESIS_WALLET, GENESIS_AMOUNT and HASH_FUNC:

bash$ DIFFICULTY=5 COINBASE1=012345678A0B0C0D0E0F0D0E0A0D0C0DE0010C01337400000000000000000000 \
GENESIS_WALLET=I_AM_GENESIS GENESIS_AMOUNT=10000000 \
VERSION=1.0 HASH_FUNC=SHA256 \
	  npm run build

HASH_FUNC can be selected from any hashing function provided by ezcrypto, namely SHA1, SHA256 and MD5. The Block hash is always double-hashed, transaction hashes are single hashed, but not using Merkle Trees yet.

Create blockchain and initial blocks / transactions:

sh$ npm run init_blockchain

The first block (the genesis block) is generated, containing a single transaction from and to the GENESIS_WALLET with amount set to GENESIS_AMOUNT.

Another block is also mined, with a few dummy transactions back and forth to two temporary wallets. Once that block has been mined, its added to the blockchain, which is then printed as a JSON struct to stdout.

Roadmap

- Implement basic blockchain. DONE
- Implement fundaental miner. DONE
- Implement fundamental wallet. DONE

- TODO: Merkle trees
- TODO: (De)serialization to/from disk

- FUTURE: Networking, confirmations, consensus, etc etc etc ?

Contributing

Read the code, understand it's style and inner workings, then fork and submit pull requests, I might merge them, I might not.

Donate

I hear it's a good idea to have your wallets exposed these days. If you appreciate the work, consider dropping off a few cents.

BTC: 34xzza81xCAtGEceZpPgMAJqw9MW2pHTFR ZEC: t1fmXwQR4whaGCXAsfjAZn9vJb1oGUe3eF3 XMR: 47KecbLbAfQUdBLvusz7dbWzrcgLsMLhs1kBQxsamGfth5GXuUttfnzjXqrT3anyZ22j7DEE74GkbVcQFyH2nNiC3eeiE4T BCN: 27WeDqwNuqJApsvks5JtBFDuShsz6iqrmVV48yXjuMai2x4BBAK28Nidi7ok6B5SQT6UXUtQgusruCoXbqUZm8VJAgbnitW

Any tiny coin is appreciated, and will encourage me to produce and share more free code.