Set of convenient utilities for verifying proof-of-humanity on-chain within Solidity smart contracts.
Proof-of-Humanity is signed proof that the transaction sender is a human rather than a bot. We are trusting the proof signer (validator) that they did use some method to prove sender humanity off-chain. That could be a CAPTCHA, biometric verification, and so on. Now we can check the validity and uniqueness of this proof on-chain before processing the transaction.
See also:
Proof-of-HUMANity on-chain: protect your smart contracts from bots
Proof-of-Humanity TRON hCaptcha Validator API
This is a basic abstract contract you should inherit from. It exposes the following API:
setHumanityValidator(<address>)
– sets the address of the humanity validator you trust. Usually, this is the address of the account used to sign proof-of-humanity in the backend server you are in control or trust. Here is an example server for hCaptcha.
Validator could be set either in contract
constructor
, or later, by the contract owner.
basicPoH(<proof>)
– ensures that the basic
proof is valid and never seen before.
sovereignPoH(<proof>)
– ensures that the sovereign
proof is valid and never seen before.
If the proof is invalid, transaction is rejected.
proof
must be provided as a parameter for a modified method (example).
Two types of proof-of-humanity are supported: basic
and sovereign
.
The basic proof is 101 bytes long. It is a random challenge and a timestamp signed by a trusted validator.
random challenge | timestamp | validator signature
32 bytes | 4 bytes | 65 bytes
Sovereign proof includes the signature of the transaction sender over the random challenge. This is useful if you want the proof to be tightened to the sender's address. The sovereign proof is 166 bytes long.
random challenge | sender signature | timestamp | validator signature
32 bytes | 65 bytes | 4 bytes | 65 bytes
npm install poh-tron-contracts
`import "poh-tron-contracts/contracts/HumanOnly.sol";`
contract MyContract is HumanOnly
constructor() {
setHumanityValidator(0x...);
}
This is the address used to sign proofs on a backend server you trust.
function doSomethingImpotant(bytes calldata proof) public basicPoH(proof)
Ensure to provide a valid
proof
when calling this function from your dApp.
- Proof-of-HUMANity on-chain: protect your smart contracts from bots
- Proof-of-Humanity TRON hCaptcha Validator API
- Proof-of-Humanity TRON React
- Proof-of-Humanity hCaptcha Validator React
- Counter dApp Example for TRON
Alex Bakoushin
MIT