How do I hide my code?

Hi everyone,

I wrote an encryption class to use in my database application and it works fine. But the thing is anyone can extract the class file from my jar and use it to dycrypt what i encrypted as they like. Or they can decompile the file catch the encryption method. Have you got any idea how to overcome this problem..

A friend of mine suggested using native libraries and compiling my file to an .exe But neither him or I got an idea on how to do it..

Thanks for your time..

Please do not post the same question to multiple forums. Let's continue the discussion in this duplicate thread, where you have an answer already.