Rails' has_secure_token API is ActiveRecord-specific, but shouldn't be difficult to port to Mongoid. This will be necessary for the Mongoid::Storage endeavor.

It ought to be implemented in such a way that Mongoid models can include this feature without needing to use all of Mongoid::Storage. Eventually, it might be ideal to split it out into its own gem (or make it part of Mongoid itself). For now, let's not put it in Mongoid because we'd like Mongoid::Storage to be usable with already-available versions of Mongoid.