title: Create a string when running an application
body: <p>I wrote a Java program and I want to make payments on it. (For Android)</p>
  
  <p>Now for the payment, you need to have a <code>RSA</code> key provided by the relevant market, which is, in fact, to identify our program from other programs and should be kept away from the hackers so that the program does not crack.</p>
  
  <p>And while Android apps are simply a few clicks away, you can see this important thread.</p>
  
  <p>I read somewhere that, in order to keep the threads hidden from the point of view of the hackers, we need to build them in <code>during the execution of the program</code>.</p>
  
  <p>How to create a string during the execution of the program, even after the program source and all its methods and classes can be seen, it is still impossible to find the desired field by implementing those methods and classes ?</p>
  
  <p>Please tell the offline method without using the server.</p>