Cookie value encryption

Is there anything built into either Ruby or Rails that can help
encrypt and decrypt values placed in a cookie?

I realize that I could store sensitive data in the server side session
instead I would like to know if cookie encryption is easily doable
(exploring options).

OpenSSL, which is poorly documented. Luckily there's EZCrypto to the
rescue (though I've never used it):

Or may be use cookie based session store, which encrypts the data.

Where can I find some docs on how to use the Cookie Based Session
Store? I'm using Rails 1.2.3 The following page makes no mention of


Oops. Cookie based session store is only in edge rails.