> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpara.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Verify Signatures with Cosmos Libraries
> Verify message and transaction signatures using CosmJS
export const Card = ({imgUrl, title, description, href, horizontal = false, newTab = false}) => {
const [isHovered, setIsHovered] = useState(false);
const handleClick = e => {
e.preventDefault();
if (newTab) {
window.open(href, '_blank', 'noopener,noreferrer');
} else {
window.location.href = href;
}
};
return ;
};
Verify signatures from signed messages to authenticate users or validate transactions using CosmJS in React Native.
## Prerequisites
## Verify Signatures
Verify ADR-036 signatures using CosmJS crypto utilities.
```typescript theme={null}
import { useState } from 'react';
import { View, Text, Button } from 'react-native';
import { fromBase64, toUtf8 } from '@cosmjs/encoding';
import { Secp256k1, Secp256k1Signature, sha256 } from '@cosmjs/crypto';
import { serializeSignDoc, makeSignDoc } from '@cosmjs/amino';
function SignatureVerification() {
const [isValid, setIsValid] = useState(null);
const verifyADR036Signature = async () => {
const pubkeyBase64 = 'A08EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQ';
const signatureBase64 = '...'; // Signature from signAmino
const originalMessage = 'Hello Para!';
const signerAddress = 'cosmos1...';
const chainId = 'cosmoshub-4';
try {
const pubkey = fromBase64(pubkeyBase64);
const signature = fromBase64(signatureBase64);
const signDoc = makeSignDoc(
[{ type: 'sign/MsgSignData', value: { signer: signerAddress, data: btoa(originalMessage) } }],
{ amount: [], gas: '0' },
chainId,
'',
0,
0
);
const serialized = serializeSignDoc(signDoc);
const messageHash = sha256(serialized);
const sig = Secp256k1Signature.fromDer(signature);
const valid = await Secp256k1.verifySignature(sig, messageHash, pubkey);
setIsValid(valid);
console.log('Signature valid:', valid);
} catch (error) {
console.error('Verification failed:', error);
setIsValid(false);
}
};
return (
{isValid !== null && Valid: {isValid ? 'Yes' : 'No'}}
);
}
```
## Next Steps
