Udacity Blockchain Capstone

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

Real Estate Marketplace

In this project you will be minting your own tokens to represent your title to the properties. Before you mint a token, you need to verify you own the property. You will use zk-SNARKs to create a verification system which can prove you have title to the property without revealing that specific information on the property.

Once the token has been verified you will place it on a blockchain market place (OpenSea) for others to purchase. Let's get started!

Token

Name: BlackDevRealEstateToken
Symbol: BDRET
Token Address:https://rinkeby.etherscan.io/token/0x3618D00992D3D32f2d876E42fEA74aF63A432280

OpenSea

Original Owner: https://rinkeby.opensea.io/accounts/0x533a5903F2b95509F39C93072302A8312f44392D
Buyer of 5 Listings: https://rinkeby.opensea.io/accounts/0x07dCC6431Ecf8756CAfb1E62c71D33dD75ee9B90

Buy Transaction: https://rinkeby.etherscan.io/tx/0x9f3b92e57e32d10c790933a94162b7e35a35327a147aae11743bc703a425c912

Contracts

SolnSquareVerifier Contract - https://rinkeby.etherscan.io/address/0x3618D00992D3D32f2d876E42fEA74aF63A432280
Verifier Contract - https://rinkeby.etherscan.io/address/0x4a92418ffAFFf2A484e6df1B33317a701ADa65B6
BlackDevRealEstateToken Contract - https://rinkeby.etherscan.io/address/0xAb9F76F5CBB182bCC8c81a975390983397b408d0

Deploying 'BlackDevRealEstateToken'
-----------------------------------
> transaction hash:    0xfd49f5cafd3fd8c49c0e256cc20ddfd904be397faa768c4c14e5a94f46195d68
> Blocks: 2            Seconds: 17
> contract address:    0xAb9F76F5CBB182bCC8c81a975390983397b408d0
> block number:        6378244
> block timestamp:     1587829087
> account:             0x533a5903F2b95509F39C93072302A8312f44392D
> balance:             15.237267732000000001
> gas used:            3080835
> gas price:           20 gwei
> value sent:          0 ETH
> total cost:          0.0616167 ETH


Deploying 'Verifier'
--------------------
> transaction hash:    0xffc2660c42c072160dbe9eb02bd52e9cba1dfdb4c659eb8660d54004fecf4c12
> Blocks: 1            Seconds: 21
> contract address:    0x4a92418ffAFFf2A484e6df1B33317a701ADa65B6
> block number:        6378246
> block timestamp:     1587829117
> account:             0x533a5903F2b95509F39C93072302A8312f44392D
> balance:             15.217413832000000001
> gas used:            992695
> gas price:           20 gwei
> value sent:          0 ETH
> total cost:          0.0198539 ETH


Deploying 'SolnSquareVerifier'
------------------------------
> transaction hash:    0x711ff998a454d6bfe19113f1c1946adffa730d4a2940de51eb151ef82d6e7e5d
> Blocks: 0            Seconds: 5
> contract address:    0x3618D00992D3D32f2d876E42fEA74aF63A432280
> block number:        6378247
> block timestamp:     1587829132
> account:             0x533a5903F2b95509F39C93072302A8312f44392D
> balance:             15.144569652000000001
> gas used:            3642209
> gas price:           20 gwei
> value sent:          0 ETH
> total cost:          0.07284418 ETH


> Saving migration to chain.
> Saving artifacts
-------------------------------------
> Total cost:          0.15431478 ETH


Summary
=======
> Total deployments:   4
> Final cost:          0.15881952 ETH
   

Testing

1. cd eth-contracts directory
2. Run truffle compile && truffle migrate --reset
3. run truffle test

Contract artifacts including ABI can be found in eth-contracts/build/contracts

Versions

Truffle

Truffle v5.0.31 (core: 5.0.31)
Solidity - 0.5.1 (solc-js)
Node v12.16.2

Project Resources

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