proddam / g-coin

A simple implementation of Blockchain for understanding easily

G Coin

A simple implementation of Blockchain for understanding easily.

It includes only basic concepts.

• Block and Hash
• Transaction and Balance
• Mining with Proof of Work
• Chain validation and consensus conflicts

Modules

bold is core function.

• blockchain : chain structure /w blocks
  • new_block: make block /w hash of previous block and current proof
  • valid: validate chain rules of all chain
• block : block structure
  • hash: hash itself
• proof : proof of work
  • find_proof
  • valid_proof
• miner : Mining new block and get rewards
• transaction : data object
• book : book of transactions
  • check_balance /w transaction history of sender account
• node
  • consensus_with_neighbor

Endpoints

• /transaction : Add a transaction and get pending transactions.
• /mine : Mining. Find proof and make block with rewards.
• /node : Add a node as a neighbor node
• /chain : Get full chain to validate.
• /chain/valid : Valid chain
• /chain/consensus : Consensus conflicts

Try using Insomnia

• Download Insomnia
• Import from insomnia.json

Try like this

• First try
  • POST /transaction
    • /w {sender: '0', recipient: 'golbin', amount: 10}
  • GET /transaction
  • GET /chain
  • POST /mine
  • GET /chain
  • GET /transaction
• Second try
  • POST /transaction
    • /w {sender: 'golbin', recipient: 'bluecat', amount: 10}
  • POST /transaction
    • /w {sender: 'golbin', recipient: 'bluecat', amount: 10}
  • POST /mine
  • GET /chain

Try endpoints to run two daemons.

python app.py --port 5000
python app.py --port 5001

• POST /node
  • to 127.0.0.1:5000 /w {address: '127.0.0.1:5001'}
• POST /node
  • to 127.0.0.1: 5001 /w {address: '127.0.0.1:5000'}
• Try several mining
• GET /chain/valid
• POST /chain/consensus

Requirements

• Python >= 3.6
• Flask >= 0.12
• Requests >= 2.18

References

• http://ecomunsing.com/build-your-own-blockchain
• https://qiita.com/hidehiro98/items/841ece65d896aeaa8a2a