title: How to protect Google Play public key when doing InApp Billing
body: <p>Actually this is a little bit silly about protecting public key (what is the definition of public key then?) but as per the <a href="http://developer.android.com/guide/google/play/billing/billing_best_practices.html" rel="noreferrer">documentation by Google</a>:</p>
  
  <blockquote>
    <p>To keep your public key safe from malicious users and hackers, do not
    embed it in any code as a literal string. Instead, construct the
    string at runtime from pieces or use bit manipulation (for example,
    XOR with some other string) to hide the actual key. The key itself is
    not secret information, but you do not want to make it easy for a
    hacker or malicious user to replace the public key with another key.</p>
  </blockquote>
  
  <p>Are there any recommended way to do it? </p>
  
  <p>I know there are many ways to do it, I just don't want to follow the same way how people handle <em>password hashing</em> in the past (e.g. md5, sha1 etc), I want to know the best practice in the above use case.</p>