On Fri, Jul 12, 2013 at 2:37 AM, Iraklis . <[email protected]> wrote:
> You are missing the following: > Files are encrypted for deduplication. That implies a way to derive a key > from the content of the files. That is if two files are similar they will > have similar ciphertexts > No, because they are encrypted under a key derived by a hash function, and one property of a secure hash function is that similar content produces completely different hashes, even if you just change one bit. Using this content hash to seed a PRNG (and derive encryption keys for the content) will produce completely different pseudorandom padding, even for similar files. -- Tony Arcieri
_______________________________________________ tahoe-dev mailing list [email protected] https://tahoe-lafs.org/cgi-bin/mailman/listinfo/tahoe-dev
