I actually tried to do a proof of concept for exactly this but gave up after assuming you could never truly trust the client to not mess with/read the data.
>>[...] assuming you could never truly trust the client to not mess with/read the data.
We have to wait for fully homomorphic encryption[1] to realize this, or a clever implementation of zero-knowledge proofs. Your proof of concept may work now if you can implement partial homomorphic encryption, perhaps something similar to CryptDB[2] or ZeroDB[3]. I read more about this in a recent Zdnet article that gives a brief summary[4].
This is the conclusion that I came to (without knowing there was a word for homomorphic encryption, thanks!). I really think this is the (ideal) future of monetizing the internet.
Maybe a job for quantum computers, if we can figure out a way to run them like we do current computers and not just in a carefully constructed environment (very cold & quiet boxes).
We have to wait for fully homomorphic encryption[1] to realize this, or a clever implementation of zero-knowledge proofs. Your proof of concept may work now if you can implement partial homomorphic encryption, perhaps something similar to CryptDB[2] or ZeroDB[3]. I read more about this in a recent Zdnet article that gives a brief summary[4].
[1] https://en.wikipedia.org/wiki/Homomorphic_encryption
[2] https://css.csail.mit.edu/cryptdb/
[3] https://zerodb.com/
[4] http://www.zdnet.com/article/encryptions-holy-grail-is-getti...