When performing biometric authentication, some times we are getting these kind of errors when i try to sign the data with private key that we get it from keychain. I was searching for document related to this but i could not.Can someone help me on this? Error message and error code Remote alert invalidated -4 UI canceled by system -4 unable to sign digest -3 Canceled by another authentication -4 Caller is not running foreground -1004 Caller moved to background -4 No identities are enrolled  -7 User has denied the use of biometry for this app -1018 Application retry limit exceeded -1 Face ID interlocked -8 Biometry lost -4 match failed -1 // To get signed data using private key SecKeyRef privateKeyReferences = [self getPrivateKey:keyNames]; if(!privateKeyReferences) { NSLog(@"Error retrieving private key"); return nil; } NSError *error; NSData *signature = CFBridgingRelease(SecKeyCreateSignature(privateKeyReferences, kSecKeyAlgorithmECDSASignatureMessageX962SHA256, (CFDataRef) data, (void *)&error)); if(!signature) { NSString *errorMessage = [NSString stringWithFormat:@"Error signing data %@.", error]; NSLog(@"%@", errorMessage); return nil; } return signature;