title: Using Touch ID for multiple user
body: <p>I am still studying for touch ID api. </p>
  
  <p>I know that touch ID will just return yes or no only when user unlock in app. </p>
  
  <p>I copy some code from here. </p>
  
  <p><a href="https://stackoverflow.com/questions/10064710/generate-key-pair-on-iphone-and-print-to-log-as-nsstring">Generate key pair on iphone and print to log as NSString</a></p>
  
  <pre><code>OSStatus status = noErr;
  NSMutableDictionary *privateKeyAttr = [[NSMutableDictionary alloc] init];
  NSMutableDictionary *publicKeyAttr = [[NSMutableDictionary alloc] init];
  NSMutableDictionary *keyPairAttr = [[NSMutableDictionary alloc] init];
  //.....................
  </code></pre>
  
  <p>Is it possible to use touch ID to differentiate multiple user? </p>
  
  <p>In iOS 9, we can encrypt key with finger print. Private key will be stored in device and app can use public key. </p>
  
  <p>Can I use that for multiple user? I just want to differentiate multiple username and password based on particular finger print. </p>