Udacity Blockchain Capstone

This is my capstone as a final udacity project for blockchain developer nanodegree in order to build a decentralized housing product.

Problem Statement

• Nowsaday, in real estate business, house listing service is still based on paper which create a lot of error and fraud.
• 25% defect and higher legal fee
• In emerging country, we find it difficult to identify the land ownership.

Requirement

• Title management process in house listing service
• Mint new token
• Using zk-SNARK to cope with verification without expose the sensitive information in public
• OpenSea is adopt as a marketplace

Test Result

truffle test

Deployed Contract (Rinkeby)

• Verifier: 0x5159fDD670DA5F5334cf37e041414b38Bd3a9308
• SolnSquareVerifier: 0x8883cCc302E8f782B9775111c89b72f2f0be1DE0

Token Minted

• 0xf699e0d83bad29e0f5169e94d9d0011b20b0b48826834651f08b4c1fc856274d
• 0x13d8fc6ba4d4c1bfd4ef1be6168bf5d3be1a26670f897adc7be9c66744ca34b9
• 0x57656312456522dff902bb4d299b839baecce0e7411de9def875b84409f7c321
• 0x8010b39bb1001070b16273677ac40c7dcf6696938694a9b2b4707c0dfa3f68fd
• 0xe317b386147deef4b5dbc937220f10701ab781da1a883084375daea0ef816ac6

via https://v5.myetherwallet.com/interface/interact-with-contract

OpenSea

Store Front Link: https://testnets.opensea.io/collection/pggtoken

Purchase Transaction:

• 0xebb1a524fc363d69661dd19f6bb2eae69a70677188605f2f41126dca4e5b7324
• 0x6ef3cf9fb106cbba474e37b21523b0ad13d423df2802abac112b3b1dc6e9ef5d
• 0x53af3366b32eb779948018927b08feb2ac6f7cec565a06e3023bd5c0911b3bfc
• 0xbe39672bb052fc900ae2c688f5a0f5961e2a62842d75820b2bb20996f729a0e9
• 0xb83b6621c70eb4df50b2bf5ee972a625067c2f4a2969f8ce49da6d876a8a601b

Project Resources

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

ABI

[
    {
      "constant": true,
      "inputs": [
        {
          "name": "interfaceId",
          "type": "bytes4"
        }
      ],
      "name": "supportsInterface",
      "outputs": [
        {
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x01ffc9a7"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "name",
      "outputs": [
        {
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x06fdde03"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "getApproved",
      "outputs": [
        {
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x081812fc"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "approve",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x095ea7b3"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "paused",
          "type": "bool"
        }
      ],
      "name": "setPaused",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x16c38b3c"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "totalSupply",
      "outputs": [
        {
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x18160ddd"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "from",
          "type": "address"
        },
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "transferFrom",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x23b872dd"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "_myid",
          "type": "bytes32"
        },
        {
          "name": "_result",
          "type": "string"
        }
      ],
      "name": "__callback",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x27dc297e"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "owner",
          "type": "address"
        },
        {
          "name": "index",
          "type": "uint256"
        }
      ],
      "name": "tokenOfOwnerByIndex",
      "outputs": [
        {
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x2f745c59"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "_myid",
          "type": "bytes32"
        },
        {
          "name": "_result",
          "type": "string"
        },
        {
          "name": "_proof",
          "type": "bytes"
        }
      ],
      "name": "__callback",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x38bbfa50"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "mint",
      "outputs": [
        {
          "name": "success",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x40c10f19"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "from",
          "type": "address"
        },
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "safeTransferFrom",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x42842e0e"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "index",
          "type": "uint256"
        }
      ],
      "name": "tokenByIndex",
      "outputs": [
        {
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x4f6ccce7"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "ownerOf",
      "outputs": [
        {
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x6352211e"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "owner",
          "type": "address"
        }
      ],
      "name": "balanceOf",
      "outputs": [
        {
          "name": "",
          "type": "uint256"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x70a08231"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "owner",
      "outputs": [
        {
          "name": "",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x8da5cb5b"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "symbol",
      "outputs": [
        {
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x95d89b41"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "approved",
          "type": "bool"
        }
      ],
      "name": "setApprovalForAll",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0xa22cb465"
    },
    {
      "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",
      "signature": "0xb88d4fde"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "tokenId",
          "type": "uint256"
        }
      ],
      "name": "tokenURI",
      "outputs": [
        {
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0xc87b56dd"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "baseTokenURI",
      "outputs": [
        {
          "name": "",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0xd547cfb7"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "owner",
          "type": "address"
        },
        {
          "name": "operator",
          "type": "address"
        }
      ],
      "name": "isApprovedForAll",
      "outputs": [
        {
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0xe985e9c5"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "newOwner",
          "type": "address"
        }
      ],
      "name": "transferOwnership",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0xf2fde38b"
    },
    {
      "inputs": [
        {
          "name": "verifierAddress",
          "type": "address"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "constructor",
      "signature": "constructor"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "name": "index",
          "type": "uint256"
        },
        {
          "indexed": false,
          "name": "solAddress",
          "type": "address"
        }
      ],
      "name": "AddingSolution",
      "type": "event",
      "signature": "0x227e3bdbb2f53676b1cd5ff3e2bedacb729b0bdbbf70677700150eb058a3e384"
    },
    {
      "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",
      "signature": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
    },
    {
      "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",
      "signature": "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925"
    },
    {
      "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",
      "signature": "0x17307eab39ab6107e8899845ad3d59bd9653f200f220920489ca2b5937696c31"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "name": "account",
          "type": "address"
        }
      ],
      "name": "Pause",
      "type": "event",
      "signature": "0x5ee71a369c8672edded508e624ffc9257fa1ae6886ef32905c18e60196bca399"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "name": "account",
          "type": "address"
        }
      ],
      "name": "UnPause",
      "type": "event",
      "signature": "0xc12ea4596a5504d11e0dcd87045fc6c80e476fca74798a09a2050e289d5a4fa2"
    },
    {
      "anonymous": false,
      "inputs": [
        {
          "indexed": false,
          "name": "fromOwner",
          "type": "address"
        },
        {
          "indexed": false,
          "name": "toOwnerd",
          "type": "address"
        }
      ],
      "name": "OwnershipTransfered",
      "type": "event",
      "signature": "0x0d18b5fd22306e373229b9439188228edca81207d1667f604daf6cef8aa3ee67"
    },
    {
      "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",
      "signature": "0xf76b4431"
    },
    {
      "constant": true,
      "inputs": [
        {
          "name": "a",
          "type": "uint256[2]"
        },
        {
          "name": "b",
          "type": "uint256[2][2]"
        },
        {
          "name": "c",
          "type": "uint256[2]"
        },
        {
          "name": "input",
          "type": "uint256[2]"
        }
      ],
      "name": "isSolutionExist",
      "outputs": [
        {
          "name": "",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function",
      "signature": "0x65280ce1"
    },
    {
      "constant": false,
      "inputs": [
        {
          "name": "to",
          "type": "address"
        },
        {
          "name": "tokenId",
          "type": "uint256"
        },
        {
          "name": "a",
          "type": "uint256[2]"
        },
        {
          "name": "b",
          "type": "uint256[2][2]"
        },
        {
          "name": "c",
          "type": "uint256[2]"
        },
        {
          "name": "input",
          "type": "uint256[2]"
        }
      ],
      "name": "mintAfterSolVerified",
      "outputs": [
        {
          "name": "success",
          "type": "bool"
        }
      ],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function",
      "signature": "0x424c9327"
    }
  ]