NSString *myLocalizedReasonString = @"For Securing App with TouchID"; if ([myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) { [myContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:myLocalizedReasonString reply:^(BOOL) success, NSError *error) { if (success) { // User authenticated successfully } else { // User failed to authenticate successfully } }]; } else { // Could not evaluate policy https://nvisium.com/blog/2016/06/22/dont-touch-me-that-way.html VULNERABLE AGAINST REVERSE ENGINEERS LocalAuthentication USABLE PAYLOAD