title: How to encrypt an ASCII character with textbook RSA in C#?
body: <p>I have a problem with calculate of ASCII value with exponent and modulus.
  I want calculate ASCII value of "K" with RSA algorithm.</p>
  
  <p>K in ascii value is 75</p>
  
  <pre><code>c   = m^e mod n
      = 75^41 mod 689
      = 316
  </code></pre>
  
  <p>Then how to make it into source code in C#? I got error "cannot implicity convert  type".</p>
  
  <p>this my source code</p>
  
  <pre><code>int n = 689;
  int e = 41;
  int d = 137;
  string value = "K";
  
  for (int i = 0; i &lt; value.Length; i++)
  {
      int c = (int)i;
      c = Math.Pow(i,e);
  }
  Console.ReadLine();
  </code></pre>