3 ms·

From here on in this is the only privacy model I will consider trustworthy for a cloud service; You have the encryption key, the data on our servers is comple

From here on in this is the only privacy model I will consider trustworthy for a cloud service; You have the encryption key, the data on our servers is completely useless without that encryption key. We are physically unable to be compelled to comply with any orders to violate your privacy from anyone. The only example of a cloud service I can think of that matches this off the top of my head is spideroak and tarsnap, perhaps also the new torrent sync? I'm not entirely certain how that works but I do recall a client side crypto key being involved in there somewhere?

plywoodtrees 13y ago
You can use things like Duplicity which locally encrypt backups and then store them to arbitrary cloud services. The problem is, if the data is opaque to the cloud service, it is very hard for it to do anything other than passively store and retrieve it, at which point it is not really a cloud service at all. And even then: they can give logs to authorities showing what you accessed when and from where, they probably know your credit card and billing details.
- etherael 13y ago
  I have an 8gb truecrypt file on dropbox, pretty much regardless of what they're compelled to do, it's secure. That's the model I think should be standard for cloud ops. However, you do bring up an interesting point, it is indeed harder to do "useful stuff" when the store is untrusted and has no idea what it's holding, string searches et al become pretty much impossible generally speaking, big bummer there. Perhaps this will be a good accelerant for the adoption of homomorphic encryption algorithms?
  - plywoodtrees 13y ago
    'Visions of a fully homomorphic cryptosystem have been dancing in cryptographers' heads for thirty years. I never expected to see one. It will be years before a sufficient number of cryptographers examine the algorithm that we can have any confidence that the scheme is secure.' -- Bruce Schneier Even without PRISM, the rise of cloud computing is a strong incentive for people to try to develop practical homomorphic encryption. Until there's a practical algorithm adoption will be limited.

plywoodtrees 13y ago

You can use things like Duplicity which locally encrypt backups and then store them to arbitrary cloud services. The problem is, if the data is opaque to the cloud service, it is very hard for it to do anything other than passively store and retrieve it, at which point it is not really a cloud service at all. And even then: they can give logs to authorities showing what you accessed when and from where, they probably know your credit card and billing details.

etherael 13y ago
I have an 8gb truecrypt file on dropbox, pretty much regardless of what they're compelled to do, it's secure. That's the model I think should be standard for cloud ops. However, you do bring up an interesting point, it is indeed harder to do "useful stuff" when the store is untrusted and has no idea what it's holding, string searches et al become pretty much impossible generally speaking, big bummer there. Perhaps this will be a good accelerant for the adoption of homomorphic encryption algorithms?
- plywoodtrees 13y ago
  'Visions of a fully homomorphic cryptosystem have been dancing in cryptographers' heads for thirty years. I never expected to see one. It will be years before a sufficient number of cryptographers examine the algorithm that we can have any confidence that the scheme is secure.' -- Bruce Schneier Even without PRISM, the rise of cloud computing is a strong incentive for people to try to develop practical homomorphic encryption. Until there's a practical algorithm adoption will be limited.