Add encryption as a new feature/option to the cookies provided with secret

I have a query and it's related to encryption of the cookies. As of now in case of signed cookies, I can see `express` module is using the cookie value as it is without tampering it and only appending HMAC encoding technique to sign the cookie using `cookie-signature` module.

We can also implement cookie encryption for localhost development (http) as a new feature/option having a secret supplied by the user which will provide a more secured way of cookie creation and transmission from server to client and vice versa.

Is this feature/option already in draft or if anyone has been already assigned? In case if not, could you assign this work to me so that I will work towards it and contribute to this module.

Let me know if this new feature/option works for you?