4 ms·
> What matters is that large cloud systems are fundamentally incapable of protecting data. I don't believe that's true. 1. Google (and others?) is already agg
by bo1024 13y ago
> What matters is that large cloud systems are fundamentally incapable of protecting data.
I don't believe that's true.
1. Google (and others?) is already aggressively increasing the amount of encryption it does on traffic between its datacenters. So they have been addressing this problem before it was even brought to light.
2. We easily have the encryption abilities to do many more things than we do with secure cloud data; we'd just have to pay more for it. For instance, I can encrypt everything the minute it leaves my laptop, store it in the cloud, and not decrypt until it hits my laptop again. Nobody but me ever gets the secret key (heck, it could be a one-time-pad and thus unbreakable). If I trust the cloud computers themselves, then I can store different secret keys on each and use strong public-key encryption to protect all traffic between different machines in the cloud, and between my machine. Breaking the system requires compromising a machine, and even then you only get the key for that machine.
3. In theory, fully homomorphic encryption could allow the best of both worlds above. I completely encrypt my data on my machine --- nobody else has the key --- then send it into the cloud where cloud companies can do operations for me like searching, sorting, filtering, etc, all without ever decrypting the data or learning what it is. They send me back the results (securely), then I decrypt. Of course, right now this would be massively slow and expensive, but progress is being made.
Naturally all of the above are subject to the "5-dollar wrench" rule or the "secret court/FISA/warrants" rule. You cannot protect your data from the people making a law that says "give up your data". But it is technologically possible and even feasible to secure data from the NSA's snooping. The tradeoff is cost and time.
- acqq 13y agoIf you would use one-time-pad before storing to the cloud you'd either need to store the very same pad on the cloud, then effectively not needing encryption, or you wouldn't need the cloud, as the amount of the encrypted data would match the amount of the pad data one to one. And homomorphic encryption is still far from being practical.
- bo1024 13y agoSure, one would more realistically use any standard encryption scheme. Agreed on homomorphic encryption as mentioned in my previous comment. But "impractical" is a far cry from "fundamentally impossible".
- acqq 13y agoImpractical is in sense "nobody can actually it, only the papers are written about it." Practically impossible to use.
- bo1024 13y agoA lot of things that were practically impossible 50 (or even 5) years ago are commonplace today.
- acqq 13y agoThat doesn't change the fact that nobody today can use homomorphic encryption, contrary to your claim.
- bo1024 13y agoI did not mean to make any such claim (hence the phrase, "in theory"). I was responding to the statement that "large cloud systems are fundamentally incapable of protecting data" by pointing out that, in theory, they are.
- BillyMaize 13y ago>In theory, fully homomorphic encryption could allow the best of both worlds above. I completely encrypt my data on my machine --- nobody else has the key --- then send it into the cloud where cloud companies can do operations for me like searching, sorting, filtering, etc, all without ever decrypting the data or learning what it is. Can you explain this to me? I don't understand how you can search encrypted data.
- bo1024 13y agoIt's mind-boggling, but possible. Here's the wikipedia link: http://en.wikipedia.org/wiki/Homomorphic_encryption http://en.wikipedia.org/wiki/Homomorphic_encryption The idea is this: I encrypt my data and give it to the cloud. I also encrypt the algorithm I want the cloud to use. In this case, it could be a search algorithm with the search query hardcoded. Right now, it would have to be encoded as a circuit and then encrpyted from there into a different circuit. The cloud runs my encrypted data through this "transformed" circuit, yielding some encrypted output. The cloud tells me the output. I then decrypt it with my original key. It's crazy that this works (longstanding open problem solved in 2005 or 06 I think). The name "homomorphic" comes from functions f, like homomorphisms, in which "order doesn't matter": f(data) = f(Decrypt(Encrypt(data))) = Decrypt(f(Encrypt(data))). Hope that makes some sense.
- BillyMaize 13y agoAh yes now it seems obvious, thanks.
- cromwellian 13y agoYou don't need full homomorphic encryption to do encrypted search, look up PKES systems, there's tons of papers on it now (http://crypto.stanford.edu/~dabo/abstracts/encsearch.html http://crypto.stanford.edu/~dabo/abstracts/encsearch.html). It's possible to encrypted keyword search with trapdoor functions in such a way that the server can't learn anything about what you're searching on, nor what is stored.
- anonymousDan 13y ago