ブロックチェーンを作ることで学ぶ 〜ブロックチェーンがどのように動いているのか学ぶ最速の方法は作ってみることだ〜 ref: https://qiita.com/hidehiro98/items/841ece65d896aeaa8a2a

blockchain.py

...

@app.route('/nodes/register', methods=['POST'])
def register_node():
    values = request.get_json()

    nodes = values.get('nodes')
    if nodes is None:
        return "Error: 有効ではないノードのリストです", 400

    for node in nodes:
        blockchain.register_node(node)

    response = {
        'message': '新しいノードが追加されました',
        'total_nodes': list(blockchain.nodes),
    }
    return jsonify(response), 201


@app.route('/nodes/resolve', methods=['GET'])
def consensus():
    replaced = blockchain.resolve_conflicts()

    if replaced:
        response = {
            'message': 'チェーンが置き換えられました',
            'new_chain': blockchain.chain
        }
    else:
        response = {
            'message': 'チェーンが確認されました',
            'chain': blockchain.chain
        }

    return jsonify(response), 200
...

file0.txt

pip install Flask==0.12.2 requests==2.18.4

file1.txt

block = {
    'index': 1,
    'timestamp': 1506057125.900785,
    'transactions': [
        {
            'sender': "8527147fe1f5426f9dd545de4b27ee00",
            'recipient': "a77f5cdfa2934df3954a5c7c7da5df1f",
            'amount': 5,
        }
    ],
    'proof': 324984774000,
    'previous_hash': "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
}

file11.txt

$ python blockchain.py
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

file12.txt

$ python blockchain.py
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

file13.txt

$ curl -X POST -H "Content-Type: application/json" -d '{
 "sender": "d4ee26eee15148ee92c6cd394edd974e",
 "recipient": "someone-other-address",
 "amount": 5
}' "http://localhost:5000/transactions/new"

file14.txt

{
  "chain": [
    {
      "index": 1,
      "previous_hash": 1,
      "proof": 100,
      "timestamp": 1506280650.770839,
      "transactions": []
    },
    {
      "index": 2,
      "previous_hash": "c099bc...bfb7",
      "proof": 35293,
      "timestamp": 1506280664.717925,
      "transactions": [
        {
          "amount": 1,
          "recipient": "8bbcb347e0634905b0cac7955bae152b",
          "sender": "0"
        }
      ]
    },
    {
      "index": 3,
      "previous_hash": "eff91a...10f2",
      "proof": 35089,
      "timestamp": 1506280666.1086972,
      "transactions": [
        {
          "amount": 1,
          "recipient": "8bbcb347e0634905b0cac7955bae152b",
          "sender": "0"
        }
      ]
    }
  ],
  "length": 3
}

file17.txt

$ curl -X POST -H "Content-Type: application/json" -d '{
    "nodes": ["http://localhost:5001"]
}' "http://localhost:5000/nodes/register"

file18.txt

$ curl -X POST -H "Content-Type: application/json" -d '{
    "nodes": ["http://localhost:5001"]
}' "http://localhost:5000/nodes/register"

file19.txt

$ curl "http://localhost:5001/mine"
$ curl "http://localhost:5000/nodes/resolve"

file2.txt

block = {
    'index': 1,
    'timestamp': 1506057125.900785,
    'transactions': [
        {
            'sender': "8527147fe1f5426f9dd545de4b27ee00",
            'recipient': "a77f5cdfa2934df3954a5c7c7da5df1f",
            'amount': 5,
        }
    ],
    'proof': 324984774000,
    'previous_hash': "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
}

file4.txt

from hashlib import sha256

x = 5
y = 0  # まだこのyがどの数字であるべきかはわからない

while sha256(f'{x*y}'.encode()).hexdigest()[-1] != "0":
    y += 1

print(f'The solution is y = {y}')

file5.txt

from hashlib import sha256

x = 5
y = 0  # まだこのyがどの数字であるべきかはわからない

while sha256(f'{x*y}'.encode()).hexdigest()[-1] != "0":
    y += 1

print(f'The solution is y = {y}')

file6.txt

>>> sha256(f'{5*21}'.encode()).hexdigest()
'1253e9373e781b7500266caa55150e08e210bc8cd8cc70d89985e3600155e860'

file8.txt

{
 "sender": "my address",
 "recipient": "someone else's address",
 "amount": 5
}

file9.txt

{
 "sender": "my address",
 "recipient": "someone else's address",
 "amount": 5
}