Symmetric integer to integer encryption

Question

I need some pointers or a practical example on how to encrypt an int to another int, and a secret key would be required to decrypt the value.

Something like:

Answer 1

You may look at this paper: Perfect Block Ciphers with Small Blocks and the slides of the presentation at the FSE 2007 conference.

The paper explains how to randomly select a permutation of n elements (e.g. the integer between 0 and n-1) which can be viewed as a cipher for this set of n elements.