Javascript to encode cookie contents into a get or post?

Question

I want to pass cookie contents from one domain to another. I don't want to get involved with actual cross-domain cookies. I was thinking of reading the cookie on the domain that sets it and then sending it as an encrypted JSON object to the domain that wants to use it.

Is there an accepted way of doing this and/or a toolkit that handles this sort of thing?

Thanks for any help or advice, -=b