Udacity Blockchain Capstone

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

Install

The repository contains Smart Contract code written solidity and tests using Javascript. To run the code:

• npm install
• Truffle Compile (use npx truffle compile if there are issues compiling to use local version of truffle)

Package versions:

• Truffle v5.0.15 (core: 5.0.15)
• Solidity - 0.5.2 (solc-js)
• Node v14.16.1
• Web3.js v1.5.3

Generating proof with zokrates

• Navigate to folder zokrates\code\

• Run zokrates docker image docker run -v $(pwd):/home/zokrates/code -it zokrates/zokrates /bin/bash

• compile the program cd code ~zokrates compile -i square/square.code

• Generate the trusted setup ~/zokrates setup

• Compute witness for your desired pair of number ~/zokrates compute-witness -a 3 9

• Generate proof ~/zokrates generate-proof

• Generate verifier.sol ~/zokrates export-verifier

Pass Truffle Test using local development blockchain

truffle compile

All contracts have been compiled as shown below:

truffle migrate

All migrations have been passed as shown below:

truffle test

All tests have been passed as shown below:

Deployed contract address (Verifier) on Rinkeby Testnet

0xA31eb7EBaC798B89e7456495321BF6d484F9becC

Deployed contract address (SolnSquareVerifier) on Rinkeby Testnet

0x9a6e9809Dc26d9Fc44e0353cd230273E97E6925c

Owner address

0xF3DbD0ba5130114b30e58c5202aA12e68d2ED12f

Contract ABI

"abi": [ { "inputs": [ { "internalType": "string", "name": "name", "type": "string" }, { "internalType": "string", "name": "symbol", "type": "string" } ], "payable": false, "stateMutability": "nonpayable", "type": "constructor" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "approved", "type": "address" }, { "indexed": true, "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "Approval", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "owner", "type": "address" }, { "indexed": true, "internalType": "address", "name": "operator", "type": "address" }, { "indexed": false, "internalType": "bool", "name": "approved", "type": "bool" } ], "name": "ApprovalForAll", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internalType": "address", "name": "_owner", "type": "address" } ], "name": "OwnershipIsTransfered", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internalType": "address", "name": "triggerAddress", "type": "address" } ], "name": "Paused", "type": "event" }, { "anonymous": false, "inputs": [ { "components": [ { "internalType": "uint256", "name": "_index", "type": "uint256" }, { "internalType": "address", "name": "_address", "type": "address" } ], "indexed": false, "internalType": "struct SolnSquareVerifier.SolutionsStruct", "name": "solutionsStruct", "type": "tuple" } ], "name": "SolutionIsAdded", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internalType": "uint256", "name": "_index", "type": "uint256" }, { "indexed": false, "internalType": "address", "name": "_address", "type": "address" } ], "name": "SolutionsIsMinted", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internalType": "address", "name": "from", "type": "address" }, { "indexed": true, "internalType": "address", "name": "to", "type": "address" }, { "indexed": true, "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "Transfer", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internalType": "address", "name": "triggerAddress", "type": "address" } ], "name": "Unpaused", "type": "event" }, { "constant": true, "inputs": [ { "internalType": "bytes32", "name": "_myid", "type": "bytes32" }, { "internalType": "string", "name": "_result", "type": "string" } ], "name": "__callback", "outputs": [], "payable": false, "stateMutability": "pure", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "bytes32", "name": "_myid", "type": "bytes32" }, { "internalType": "string", "name": "_result", "type": "string" }, { "internalType": "bytes", "name": "_proof", "type": "bytes" } ], "name": "__callback", "outputs": [], "payable": false, "stateMutability": "pure", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "approve", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "address", "name": "owner", "type": "address" } ], "name": "balanceOf", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "getApproved", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [], "name": "getBaseTokenURI", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [], "name": "getName", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [], "name": "getOwner", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [], "name": "getSymbol", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "address", "name": "owner", "type": "address" }, { "internalType": "address", "name": "operator", "type": "address" } ], "name": "isApprovedForAll", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "mint", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "ownerOf", "outputs": [ { "internalType": "address", "name": "", "type": "address" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "safeTransferFrom", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" }, { "internalType": "bytes", "name": "_data", "type": "bytes" } ], "name": "safeTransferFrom", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "bool", "name": "approved", "type": "bool" } ], "name": "setApprovalForAll", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "bool", "name": "status", "type": "bool" } ], "name": "setter", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "bytes4", "name": "interfaceId", "type": "bytes4" } ], "name": "supportsInterface", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "uint256", "name": "index", "type": "uint256" } ], "name": "tokenByIndex", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "address", "name": "owner", "type": "address" }, { "internalType": "uint256", "name": "index", "type": "uint256" } ], "name": "tokenOfOwnerByIndex", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [ { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "tokenURI", "outputs": [ { "internalType": "string", "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": true, "inputs": [], "name": "totalSupply", "outputs": [ { "internalType": "uint256", "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "from", "type": "address" }, { "internalType": "address", "name": "to", "type": "address" }, { "internalType": "uint256", "name": "tokenId", "type": "uint256" } ], "name": "transferFrom", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "address", "name": "newOwner", "type": "address" } ], "name": "transferOwnership", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": true, "inputs": [], "name": "verifier", "outputs": [ { "internalType": "contract Verifier", "name": "", "type": "address" } ], "payable": false, "stateMutability": "view", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "uint256", "name": "_index", "type": "uint256" }, { "internalType": "address", "name": "_address", "type": "address" } ], "name": "addSolution", "outputs": [], "payable": false, "stateMutability": "nonpayable", "type": "function" }, { "constant": false, "inputs": [ { "internalType": "uint256", "name": "_index", "type": "uint256" }, { "internalType": "address", "name": "_address", "type": "address" } ], "name": "mintNewNFT", "outputs": [ { "internalType": "bool", "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" } ]

Contract address on rinkeby.etherscan: https://rinkeby.etherscan.io/address/0x9a6e9809Dc26d9Fc44e0353cd230273E97E6925c

Minting tokens

https://www.myetherwallet.com/interface/interact-with-contract

OpenSea marketplace

https://testnets.opensea.io/assets/0x9a6e9809dc26d9fc44e0353cd230273e97e6925c/3 https://testnets.opensea.io/assets/0x9a6e9809dc26d9fc44e0353cd230273e97e6925c/6 https://testnets.opensea.io/assets/0x9a6e9809dc26d9fc44e0353cd230273e97e6925c/9 https://testnets.opensea.io/assets/0x9a6e9809dc26d9fc44e0353cd230273e97e6925c/12 https://testnets.opensea.io/assets/0x9a6e9809dc26d9fc44e0353cd230273e97e6925c/15

Token Storefront on Opensea

https://testnets.opensea.io/collection/pvm-capstone-project

transactions on market place

https://rinkeby.etherscan.io/tx/0xda063eb8c298172066e12ea8cfd37831838a8731eda030cc5b977da3ba4adb28 https://rinkeby.etherscan.io/tx/0xc11764d6f89b8c38aeea697fa5f6b7d029a3fd38cce4688b7d62fbb9855ff790 https://rinkeby.etherscan.io/tx/0xe192588df88790707cc9b446653a3a72654379a667e9005ac8cd15e43756362f https://rinkeby.etherscan.io/tx/0x9f2010a078ee7e9736cd7bfb8f7bfe64ed8792fbbccaa3f062dd1b44af04b886 https://rinkeby.etherscan.io/tx/0x43f9ef74849b5df2d48dc215bf1cbc016e876522103ddc1aee16e7e45b84d43f

Project Resources

• Visual Studio Code
• Truffle Framework
• Ganache - One Click Blockchain
• Open Zeppelin
• Docker
• ZoKrates