Is it illegal to decrypt redbox dvds for personal use?

I began to start a program called DVD shrink which shrinks the dvd and then if there is a copy protection thing, it decrypts it. I then thought that this might be illegal and dont want to finish it, so i only made it through about 3% of the decryption process and then canceled. So is it legal for me to continue or no? If not, what will happen?