CaptainCapslock

I would like a store-only key. Let me explain. Right now there are two types of keys: 1. Full access key 2. Read-only key I'd like to see a 3rd type of key which would make the reading of files also forbidden. So that I can ask my friend who lives somewhere else to store my files, without being able to look through my photos. And vise-versa. By having a 3rd key, it would also become possible to store my data at a 3rd party without having to worry.