Skip to main content
5 events
when toggle format what by license comment
Apr 13, 2017 at 12:48 history edited CommunityBot
replaced http://crypto.stackexchange.com/ with https://crypto.stackexchange.com/
Oct 1, 2011 at 5:21 comment added Zooko The second attack, which we call "learn the remaining information", is not so obvious, and as far as I know nobody was aware of this attack until 2008 when Drew Perttula and Brian Warner developed it as an attack against the Tahoe-LAFS secure filesystem. In the "learn the remaining information" attack, the attacker can make guesses about a few secret, random, unknown parts of a larger file and then find out if one of their guesses is correct. Please see the write-up at: tahoe-lafs.org/hacktahoelafs/drew_perttula.html
Oct 1, 2011 at 5:19 comment added Zooko There are two possible attacks. The first one, which we call the "confirmation of a file attack" is the obvious problem that deduplication exposes the fact that the two things were the same as each other. This issue was immediately appreciated and discussed when convergent encryption was first proposed (not under that name) on the cypherpunks mailing list in 1996. (Before Microsoft applied for a patent on convergent encryption, so the cypherpunks discussion is prior art that invalidates the Microsoft patent.)
Sep 28, 2011 at 14:23 comment added Rory Alsop Can you expand just a little here - couple of bullet points on the subtlety you mention would help users.
Sep 23, 2011 at 16:14 history answered Zooko CC BY-SA 3.0