> For the complete documentation index, see [llms.txt](https://docs.bitoftrade.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bitoftrade.com/for-developers/cross-chain-messaging-protocol/how-it-works/signers-registry-contract.md).

# Signers Registry Contract

Signers Registry contract is used by other smart contracts to verify if the signature was created by the whitelisted signer. This smart contract has to be deployed on each supported chain. 

SignersRegistry implements this interface:

```solidity
interface ISignersRegistry {
    function isPublicWhitelisted(address signer) view external returns (bool);
    function isPrivateWhitelisted(address signerAdmin, address signer) view external returns (bool);
}
```

The signer could be `public` or `private`. 

* Anyone can use the `public` signer for supported chains.
* The `Private` signer could be used for specific dApps, chains, etc. Such signers are restricted and closed for the community. Contact us if you want to implement a private signer. 

See the [example](/for-developers/cross-chain-messaging-protocol/quick-start/receive-event.md) to understand how to use Signers Registry smart contract.

See deployed smart contract on [explorer](https://polygonscan.com/address/0x3E0387bDcCe1b2A416700FC075f8c33c3A5f7E07#readProxyContract).


---

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