4 ms·
A delta of changes in an encrypted container should be very close to the size of the full container, shouldn't? It seems this will only be feasible when we hav
by SugoiDev 9y ago
A delta of changes in an encrypted container should be very close to the size of the full container, shouldn't?
It seems this will only be feasible when we have homorphic encryption ready.
If someone is interested on that kind of encryption, see "A FULLY HOMOMORPHIC ENCRYPTION SCHEME"[1] and "Fully Homomorphic Encryption without Bootstrapping
"[2]
[1] https://crypto.stanford.edu/craig/craig-thesis.pdf https://crypto.stanford.edu/craig/craig-thesis.pdf
[2] https://eprint.iacr.org/2011/277.pdf https://eprint.iacr.org/2011/277.pdf
- maxton 9y agoThat would depend on the cipher mode, no? Assuming the container is using something like CTR, the diff should only consist of changed bytes.
- deleted 9y ago[deleted]
- mikeash 9y agoAny encrypted disk image will work this way. It doesn’t require anything like homomorphic encryption, just a bit of metadata and key management.
- RasputinsBro 9y agoNo. AES encrypts blocks (I think 256kb?). So that's the only thing you have to sync.
- syrrim 9y agoIf you use plain AES ECB, then little penguins will show up in your encrypted data. You would want to use a disk encryption scheme, like XTS, where the encryption is not just based on the data of the block, but also on the index of the block, to prevent identical blocks at different locations from looking identical. You also want it to be based on a nonce of some sort, to prevent attackers from reverting a block to an older copy.
- RasputinsBro 9y agoPenguins? What are you talking about? I don't care about low-level encryption details. That's why I use encryption software instead of coding my own.
- kevin_thibedeau 9y agoECB has issues: https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Electronic_Codebook_%28ECB%29 https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation...
- UncleMeat 9y agoYou should absolutely care about the difference between ECB and a stream cipher mode like CBC. ECB is way less safe.
- rdtsc 9y agoWell the whole hard drive is not overwritten every time a file changes when using disk encryption, so definitely not necessary.