title: What encryption algorithm preserves file differences?
body: <p>I would like to encrypt a file with most secure algorithm that also meets the following requirement.</p>
  
  <p>Let's say we have a text file that has 100 Bytes and we encrypt it.
  Now we change 1 byte in original file and encrypt again. </p>
  
  <p>If we make a diff of the encrypted files then ideal encryption algorithm should produce the shortest diff possible - e.g. 1 byte.</p>
  
  <p>(Essentially I want to do a incremental backup of encrypted files and minimize bandwidth requirements)</p>