title: Character for character encryption
body: <p>is there any available library/algorithm to have a character for character based encryption mechanism. what I basically mean is, that if say the input text is <code>someText</code>, then the encrypted text should have the same number of characters.</p>
  
  <p>from our exploration of asymmetric encryption mechanisms, we feel character for character encryption can't be achieved through that.</p>
  
  <p>it is preferable that the solution be a "key" based solution, since we need to encrypt the input text through different applications [one of them is actually an embedded application within a custom hardware - and the manufacturer would prefer a key based encryption logic]. the security threat of losing our key is not significant, and is an acceptable risk.</p>