hmm, so we stuck extentions on hashes and keys and signatures, but we didn't really have a rationale for how they would be used, just thinking - this will be important one day, when we need to add more algorithms.

maybe it should be <blob_id>#<key>.boxkey? or if we take a acme plummer like approach, we can easily fallback to a more well defined system in the future.

@vendan one day I'd like to understand what javascript did to hurt you so much