Node-Blockchain-CryptoCurrency

---

A powerful and secure decentralized Blockchain Network with CryptoCurrency.

• References : Bitcoin White Paper - Bitcoin: A Peer-to-Peer Electronic Cash System By Satoshi Nakamoto

Features

• It includes an API to interact with the Blockchain.
• It signs Transactions with cryptography and digital signature.
• Secured Wallets
• Supports Real-time exchange of CryptoCurrency.
• Generate hashes for blocks in the chain.
• Real-time connected peer-to-peer server using WebSockets.
• Proof-of-work algorithm implemented.
• Transaction Pool for a real-time list of incoming data.
• Mining

Installation

You can Run the following command using Terminal/CMD:

$npm install

Usage

The API is built with NodeJS and Express.You can interact with the API.
For demonstration:

Note :Requires Nodemon

• Run the server:

  $npm run dev 
  

  Output :

  > nodemon ./app
  
  [nodemon] 1.17.5
  [nodemon] to restart at any time, enter `rs`
  [nodemon] watching: *.*
  [nodemon] starting `node ./app.js`
  Listening for Peer-to-Peer connections on port : 5000
  server started on port 3000
  
  
  

• To start another instance (peer)

  $ HTTP_PORT=3001 P2P_PORT=5001 PEERS=ws://localhost:5000 npm run dev
  

  Output :

   > nodemon ./app
  
   [nodemon] 1.17.5
   [nodemon] to restart at any time, enter `rs`
   [nodemon] watching: *.*
   [nodemon] starting `node ./app.js`
   Listening for Peer-to-Peer connections on port : 5001
   server started on port 3001
   Socket Connected!
   Received chain is not longer than the current chain.
  
  

Methods

• To get all the blocks of the blockchain

  GET http://localhost:3000/blocks

  Response:

  [
    {
        "timeStamp": "Genesis Time",
        "lastHash": "----",
        "hash": "k1S2-P1s2",
        "data": [],
        "nonce": 0,
        "difficulty": 4
    }
   ]
  

• To get own Public Key

  GET http://localhost:3000/publicKey

  Response:

  {
    "PublicKey": "049130b76348c0ff2ff7c268f1c3344c50859309e9b767f34bd63e3683aa12bb3442cba91de6fd6e5f75868cdd955b0f34e23adfc305c18f39c54c2e588d361926"
  }
  

• Mine or add blocks to the blockchain

  POST http://localhost:3000/mine

  JSON Input :

  {
  "data" : "foo-bar"
  }
  

  Response:

    [
    {
        "timeStamp": "Genesis Time",
        "lastHash": "----",
        "hash": "k1S2-P1s2",
        "data": [],
        "nonce": 0,
        "difficulty": 4
    },
    {
        "timeStamp": 1529268657715,
        "lastHash": "k1S2-P1s2",
        "hash": "000fa69a765a699bfc58c24781412ba738232f5af29e3bde0f9fba47d16d3006",
        "data": "foo-bar",
        "nonce": 7211,
        "difficulty": 3
    }
    ]
  

• To perform Transaction And Send Cryptocurrency using someone's Public key

  POST http://localhost:3000/transact

  JSON Input :

  {
    "recipient" : "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864",
    "amount"	: 50
  }
  

  Response:

  [
    {
        "id": "8676c910-7272-11e8-86ef-85c52672e7ed",
        "input": {
            "timeStamp": 1529269684257,
            "amount": 500,
            "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761",
            "signature": {
                "r": "861d22558e1387ea4e081c156dd796b24fd2ba783b218ffc7a853207f2361b68",
                "s": "cf5677f392142cd083df68189b3200a19e32e2ea1da34d63c2a188ef8a0a6186",
                "recoveryParam": 0
            }
        },
        "outputs": [
            {
                "amount": 450,
                "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761"
            },
            {
                "amount": 50,
                "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
            }
        ]
    }
  ]
  

• To get all valid transactions

  GET http://localhost:3000/transactions

  Response:

   [
    {
        "id": "8676c910-7272-11e8-86ef-85c52672e7ed",
        "input": {
            "timeStamp": 1529269684257,
            "amount": 500,
            "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761",
            "signature": {
                "r": "861d22558e1387ea4e081c156dd796b24fd2ba783b218ffc7a853207f2361b68",
                "s": "cf5677f392142cd083df68189b3200a19e32e2ea1da34d63c2a188ef8a0a6186",
                "recoveryParam": 0
            }
        },
        "outputs": [
            {
                "amount": 450,
                "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761"
            },
            {
                "amount": 50,
                "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
            }
        ]
    },
    {
        "id": "3f0f8f70-7273-11e8-a5c5-f977b3bc0a96",
        "input": {
            "timeStamp": 1529269993959,
            "amount": 500,
            "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864",
            "signature": {
                "r": "9087affe4996cf63431214ed6e6081739cefdf2dba090b36b71c017a34eb5d87",
                "s": "e7bce503b37bee6246faf42822e8ba5f5a9e9ab07cabf66eb754674322939047",
                "recoveryParam": 1
            }
        },
        "outputs": [
            {
                "amount": 400,
                "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
            },
            {
                "amount": 100,
                "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761"
            }
        ]
    }
    ]
  

• Mine transactions to add rewards to the Miners

By default each miner will get 50 Reward points for mining

GET http://localhost:3001/mine-transactions

Response:

[
  {
      "timeStamp": "Genesis Time",
      "lastHash": "----",
      "hash": "k1S2-P1s2",
      "data": [],
      "nonce": 0,
      "difficulty": 4
  },
  {
      "timeStamp": 1529270176969,
      "lastHash": "k1S2-P1s2",
      "hash": "00009971fd40b7bf881bf5972cef499ebdf1628d97457d599e2162d9dcf8a846",
      "data": [
          {
              "id": "8676c910-7272-11e8-86ef-85c52672e7ed",
              "input": {
                  "timeStamp": 1529269684257,
                  "amount": 500,
                  "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761",
                  "signature": {
                      "r": "861d22558e1387ea4e081c156dd796b24fd2ba783b218ffc7a853207f2361b68",
                      "s": "cf5677f392142cd083df68189b3200a19e32e2ea1da34d63c2a188ef8a0a6186",
                      "recoveryParam": 0
                  }
              },
              "outputs": [
                  {
                      "amount": 450,
                      "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761"
                  },
                  {
                      "amount": 50,
                      "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
                  }
              ]
          },
          {
              "id": "3f0f8f70-7273-11e8-a5c5-f977b3bc0a96",
              "input": {
                  "timeStamp": 1529269993959,
                  "amount": 500,
                  "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864",
                  "signature": {
                      "r": "9087affe4996cf63431214ed6e6081739cefdf2dba090b36b71c017a34eb5d87",
                      "s": "e7bce503b37bee6246faf42822e8ba5f5a9e9ab07cabf66eb754674322939047",
                      "recoveryParam": 1
                  }
              },
              "outputs": [
                  {
                      "amount": 400,
                      "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
                  },
                  {
                      "amount": 100,
                      "address": "0423141eab6d1875ae22a96dac794328ba962913bdbbb6a7e1c9cfb4ffd0e7989fac58a722d79b4a5891fb8875831e20e9e54e58856ac074ef15eb7d6ef3a0a761"
                  }
              ]
          },
          {
              "id": "abfa8e50-7273-11e8-a5c5-f977b3bc0a96",
              "input": {
                  "timeStamp": 1529270176693,
                  "amount": 500,
                  "address": "0480773fa0af4a2978eb78863df0576aa4105d92dba27cdc39559e1ff1720053f05b6e799221243e6721cb59d33ebd6d4f0fbba0e88c73abc5abcce0900e67a228",
                  "signature": {
                      "r": "32784816ab2fcb83f3521d41ac2044fc036fd3900e98fee42b93c59307badd",
                      "s": "f2b20c66d961e740cf90c9f75e92b290dc7faacc7bd05fdb70b136ae96f66db0",
                      "recoveryParam": 0
                  }
              },
              "outputs": [
                  {
                      "amount": 50,
                      "address": "047648c967013eec3f332d103227eee7decde237cac3984bb9523f70f6cbc486060906f412f19039d70f8892a9b388a51664a740adca61e7386a038cb99ce42864"
                  }
              ]
          }
      ],
      "nonce": 10134,
      "difficulty": 3
  }
]

Integration Tests

You can run integration tests using the following command :

$npm run test

Note : Testing requires JEST

Requirements

• Node.js

Dependencies

• body-parser ^1.18.3
• crypto-js ^3.1.9-1
• elliptic ^6.4.0
• express ^4.16.3
• uuid ^3.2.1
• WebSockets ^5.2.0

Dev Dependencies

• jest ^23.1.0
• nodemon ^1.17.5

Contributing

I welcome pull requests, bug fixes and issue reports. Before proposing a change, please discuss your change by raising an issue.

License

This is distributed under the MIT license found in the LICENSE file.

Author

• Kumar Saurabh