I didn't find any implementations of this package and was interested in testing out use cases, so I have a crude initial package available.

Info on the package and a few suggested use models:

https://github.com/Tarsnap/spiped

The git repo for the beta:

https://github.com/InkblotAdmirer/custom_feed

Some notes on the config/init are in the README so I won't duplicate here.

If anyone wants to pick it up and maintain it, go for it.  If it gets interest and turns into something that should be available in the package feeds I may step up.

Note that this information was originally shared in the developer's corner but since it turned into an actual package I figured it would get more opportunity for sharing here.  I'm blown away that it hasn't already been packaged:  encryption + authentication and simple use model.