title: Function mcrypt_get_iv_size() is deprecated in codeigniter on PHP version 7.1
body: <p>When I <strong>encrypt</strong> my <strong>ID</strong> using <strong>encrypt library</strong> that time it gives me an error like :</p>
  
  <p><a href="https://i.stack.imgur.com/Xm0vO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Xm0vO.png" alt="enter image description here"></a></p>
  
  <p>Thanks for your help</p>