Validate public key with the signature -react native biometrics

Question

I am trying to use react native biometrics but after I've created and stored the public key(as a state in the example code below), it never matches with the signature generated afterward with the same finger. How can I verify the fingerPrint?

code:

registerFingerPrint = () => {
    Biometrics.isSensorAvailable()
    .then((biometryType) => {
      if (biometryType === Biometrics.TouchID) {
        Biometrics.createKeys('Confirm fingerprint')
        .then((publicKey) => {
          console.log("create", publicKey)
          this.setState({
            create: publicKey
          })
        })
      } 
    })
  }

  fingerPrintCheck = () => {
    Biometrics.createSignature('Sign in', payload)
    .then((signature) => {
      if (this.state.create === signature){
        console.log("success");
      }else {
        console.log('failure'); //always returns failure here
      }
    })
  }

  render() {
    return (
      <View style={styles.container}>

        <TouchableHighlight onPress={()=> this.registerFingerPrint()}>
          <Text style={{ marginBottom: 10}}>
            Register
          </Text>
        </TouchableHighlight>

        <TouchableHighlight onPress={()=> this.fingerPrintCheck()}>
          <Text>
            Authenticate with Biometrics
          </Text>
        </TouchableHighlight>
      </View>
    );
  }
}

Answer 1

 let epochTimeSeconds = Math.round((new Date()).getTime() / 1000).toString()
 let payload = epochTimeSeconds +'some message' ;

  Biometrics.createSignature('Sign in Test', payload)
  .then((signature) => {
    console.log(payload+" signature "+signature)
    verifySignatureWithServer(signature, payload)
  })

you need to check the validation in server side using the generated signature and payload combination.

go to this site and paste the generated public key, signature , payload and verify it.

https://8gwifi.org/RSAFunctionality?rsasignverifyfunctions=rsasignverifyfunctions&keysize=512