How to encrypt Ruby script..

For simple cases I use

openssl des3 -salt -in $SOURCE -out $DEST

where $SOURCE is the name of the file I want to encrypt and $DEST is
the name of the file the encrypted data will be written to.

Why would it run? It's no longer a Ruby file, it's *encrypted*!

))))))))))

Drip-feeding information like this is very frustrating.

http://www.catb.org/esr/faqs/smart-questions.html
(tl/dr: Please outline your problem, your attempted solutions, and the
errors you've had)

Ruby does not have an "encrypted mode"

You asked "Can any one tell me how to encrypt one ruby script", you
got the answer to your question

Describe the problem you are trying to solve rather than making things
up (such as encrypted mode ruby)

Puts the RHCE certificate in perspective if you didn't know what the
openssl command was going to do to the source file