A front-end connecting to a smart contract on the Ethereum blockchain, which allows saving a timestamped SHA-256 hash for a document.
Hashes are calculated in-browser and sent using Web3.
By default a Web3 injected into the browser is used (e.g. MetaMask or Mist).
The contract is deployed on mainnet, rinkeby and kovan.
If no Web3 object is found the code connects via a back-end to the INFURA API. In this case the Rinkeby network is used.
the back-end uses a file keys.json with private keys and api keys, which is not included the public repository for obvious reasons. The syntax is:
{
"account" : "<ethereum account>",
"privKey" : "<account private key without leading 0x>",
"infuraApiKey": "<infura API key>"
}
A working version is deployed at (https://block-cert.herokuapp.com/).
This project is licensed under the terms of the MIT license.