Fast, simple to use symmetric cipher for integer encryption in Java

Question

What is in Java a cipher function for integer encryption having these properties?:

• Fast
• Symmetric-key algorithm
• Simple to use (i.e. a couple of

Answer 1

You should never implement a cipher yourself if you want any security. There's just too much what can get wrong.

But you can write your numbers into a byte[] and use a cipher provided with Java like described in this answer.