Every attempt to use 'last' in the loop failed to achieve my goal of dumping out of the current iteration and going onto the next. So, I went back to an old shell script method that worked. I am evaluating your suggestion in the while loop to see if this would have worked using my method in the for loop.
I used the for loop to evaluate one character at a time from the decrypted message to I can bomb out sooner and not have to evaluate the entire message. Since I have not yet groc'd your use of the regex, I am not sure it does the same thing though it looks like it.