how rijndeal works

Hello,

I've used Rijndael in my application for encryption/decryption. This code was originally written in VB by P. Fresle and later optimized/overhauled for efficiency by David Midkiff and implemented as a class. I just want to clarify some things I'm not sure of.

When encrypting a string/text, we supply the input string and a keycode. I wanted that the encrypted string will be 128 characters only. Is that possible? And how will I do it?

Thanks.