title: Storing authentication token on iOS
body: <p>I am building an iOS application and the user authenticates with my web service. I don't want them to login every time the app launches (the token lasts a month). So I'd like to cache this on the device somewhere. </p>
  
  <p>What's the best way to do this, securely?</p>
  
  <p>Can I just rely on the app remaining suspended and keeping the token in 'memory'?</p>