rizoom / blockchain-nd-erc721-zksnarks-zokrates-opensea

Capstone: Real Estate Marketplace with ERC721 and zk-SNARKs

Udacity Blockchain Capstone

The capstone will build upon the knowledge you have gained in the course in order to build a decentralized housing product.

Notes

• truffle version: 5.0.40
• node version: 8.9.4

Project has been developed and tested with Ganache CLI v1.2.2 on port number 8545

ZoomToken is the ERC721 Mintable custom token contract.

Deployment on Rinkeby

   Deploying 'SquareVerifier'
   --------------------------
   > transaction hash:    0x6da2cf1e8197977840f1cc30f1e93c75a763e3dbd2287a8f118718165182aa7a
   > Blocks: 0            Seconds: 8
   > contract address:    0x1Ee750787C789cbeE2D78892C5d01AdFD4f4f369
   > block number:        5344539
   > block timestamp:     1572307207
   > account:             0x8CfEf6Ebb3E734Bc870Af83fd081D741211d065d
   > balance:             11.313389495
   > gas used:            1268520
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.0253704 ETH


   Deploying 'SolnSquareVerifier'
   ------------------------------
   > transaction hash:    0x3beb0abb3ab91cffc19ee6cd056ffa53ee94b03179b88c829313c2a0ef0f19ad
   > Blocks: 0            Seconds: 8
   > contract address:    0x7eD7aDfab562abd7fb954b4c25AF76F40f595211
   > block number:        5344540
   > block timestamp:     1572307222
   > account:             0x8CfEf6Ebb3E734Bc870Af83fd081D741211d065d
   > balance:             11.205269715
   > gas used:            5405989
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.10811978 ETH

Token minting

A simple NodeJS script has been used to mint the 10 tokens. truffle exec scripts\mint.js --network rinkeby

OpenSea

Storefront : https://rinkeby.opensea.io/storefront/zoom-3 Account that minted the ten tokens : https://rinkeby.opensea.io/accounts/0x8cfef6ebb3e734bc870af83fd081d741211d065d Account that bought five tokens : https://rinkeby.opensea.io/accounts/0x19e561847e74af72968392ad90645a771033b6e5 One of the bought token : https://rinkeby.opensea.io/assets/0x7ed7adfab562abd7fb954b4c25af76f40f595211/4

Contract ABIs

SquareVerifier

[
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "s",
        "type": "string"
      }
    ],
    "name": "Verified",
    "type": "event"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "a",
        "type": "uint256[2]"
      },
      {
        "name": "b",
        "type": "uint256[2][2]"
      },
      {
        "name": "c",
        "type": "uint256[2]"
      },
      {
        "name": "input",
        "type": "uint256[2]"
      }
    ],
    "name": "verifyTx",
    "outputs": [
      {
        "name": "r",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

SolnSquareVerifier

[
  {
    "constant": true,
    "inputs": [
      {
        "name": "interfaceId",
        "type": "bytes4"
      }
    ],
    "name": "supportsInterface",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "getApproved",
    "outputs": [
      {
        "name": "",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "from",
        "type": "address"
      },
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_myid",
        "type": "bytes32"
      },
      {
        "name": "_result",
        "type": "string"
      }
    ],
    "name": "__callback",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "owner",
        "type": "address"
      },
      {
        "name": "index",
        "type": "uint256"
      }
    ],
    "name": "tokenOfOwnerByIndex",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_myid",
        "type": "bytes32"
      },
      {
        "name": "_result",
        "type": "string"
      },
      {
        "name": "_proof",
        "type": "bytes"
      }
    ],
    "name": "__callback",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [],
    "name": "unpause",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "mint",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "from",
        "type": "address"
      },
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "safeTransferFrom",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "index",
        "type": "uint256"
      }
    ],
    "name": "tokenByIndex",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "paused",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "a",
        "type": "uint256[2]"
      },
      {
        "name": "b",
        "type": "uint256[2][2]"
      },
      {
        "name": "c",
        "type": "uint256[2]"
      },
      {
        "name": "input",
        "type": "uint256[2]"
      }
    ],
    "name": "verifyTx",
    "outputs": [
      {
        "name": "r",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "ownerOf",
    "outputs": [
      {
        "name": "",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [],
    "name": "pause",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "owner",
    "outputs": [
      {
        "name": "",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "isOwner",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "approved",
        "type": "bool"
      }
    ],
    "name": "setApprovalForAll",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "from",
        "type": "address"
      },
      {
        "name": "to",
        "type": "address"
      },
      {
        "name": "tokenId",
        "type": "uint256"
      },
      {
        "name": "_data",
        "type": "bytes"
      }
    ],
    "name": "safeTransferFrom",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "tokenURI",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "baseTokenURI",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "owner",
        "type": "address"
      },
      {
        "name": "operator",
        "type": "address"
      }
    ],
    "name": "isApprovedForAll",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "transferOwnership",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "index",
        "type": "uint256"
      },
      {
        "indexed": false,
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "SolutionAdded",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "s",
        "type": "string"
      }
    ],
    "name": "Verified",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "to",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "approved",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "tokenId",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "operator",
        "type": "address"
      },
      {
        "indexed": false,
        "name": "approved",
        "type": "bool"
      }
    ],
    "name": "ApprovalForAll",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "caller",
        "type": "address"
      }
    ],
    "name": "Paused",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "caller",
        "type": "address"
      }
    ],
    "name": "Unpaused",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "previousOwner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "OwnershipTransferred",
    "type": "event"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "a",
        "type": "uint256[2]"
      },
      {
        "name": "b",
        "type": "uint256[2][2]"
      },
      {
        "name": "c",
        "type": "uint256[2]"
      },
      {
        "name": "input",
        "type": "uint256[2]"
      }
    ],
    "name": "addSolution",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "solutionIndex",
        "type": "uint256"
      }
    ],
    "name": "mintWithSolution",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

Project Resources

• Remix - Solidity IDE
• Visual Studio Code
• Truffle Framework
• Ganache - One Click Blockchain
• Open Zeppelin
• Interactive zero knowledge 3-colorability demonstration
• Docker
• ZoKrates