title: How to identify .apk has been modified on client side
body: <p>I have an mobile app, which users will be installing on their mobile phone.</p>
  
  <p>I want to make it secure, attacker should not be allowed to modify the .apk file.
  i have taken care that My app will not work on rooted devices.</p>
  
  <p>server should be able to identify if attacker has modified some code or redirected to external links.</p>
  
  <p>How can i achieve the above scenario ?</p>