[zimbatm]

Rails had encrypted cookies for ages

[wtetzner]

I think wyldfire was referring to the part about generating a new key on launch. Of course, Rails might do that too, for all I know.

[floatboth]

uhh generating a new key on launch means every time you restart the app, everyone's cookies must be reset because the old ones can't be decrypted anymore.

It's just a convenience feature for development.