title: Securing string in APK
body: <p>I am developing an android app using Mono for Android by Xamarin. I am currently working on adding in-app-purchase capability using the Google Play API. To do so, I need to send Google the public license key from within my app. Regarding this issue, Google recommends the following:</p>
  
  <blockquote>
    <p>Security Recommendation: It is highly recommended that you do not
    hard-code the exact public license key string value as provided by
    Google Play. Instead, you can construct the whole public license key
    string at runtime from substrings, or retrieve it from an encrypted
    store, before passing it to the constructor. This approach makes it
    more difficult for malicious third-parties to modify the public
    license key string in your APK file.</p>
  </blockquote>
  
  <p>I have never dealt with encryption, hacking/cracking or any of other facet of software security, so I am not sure how to implement Google's advice. My question is how does one <em>adequately</em> secure a string in an Android APK made with Mono for Android without having to be a security expert?</p>