On Thursday 12 June 2008 23:13, Ian Clarke wrote: > On Thu, Jun 12, 2008 at 5:04 PM, Michael Rogers <m.rogers at cs.ucl.ac.uk> wrote: > > Ian Clarke wrote: > >> I don't see why nodes couldn't inform their neighbors immediately if > >> one of their neighbors goes offline, or comes online. > > > > Seems like it might make correlation attacks easier if you know how many > > active neighbours a node has and what their locations are. It might also > > make long-term intersection attacks easier by revealing when users are > > online.
The information is available now from swapping, it's a question of making it more reliable, up to date and accurate. > > It is always possible, when you share more information, that you are > making attacks easier, although it would be nice to have a specific > description of an attack. Correlation attacks: statistical attack based on recognising content, work out how likely it is that your peer is the source. This is somewhat easier with the above mechanism because we get a faster notification of when a node goes offline. Long-term intersection attack: Correlate the time at which inserts, requests etc which can be tied to a specific identity happen with the time at which a specific node is known to be online or offline. Generally this is much less of a threat to Freenet than to a real-time mixnet. The mechanism we are describing would make it easier but only when attacking your peers' peers. And probably not by very much as we should get a notification within minutes via swapping anyway. > > We may want to think about whether, if I have a darknet neighbor, a > "friend", but I am opennet (so I am connected to some strangers), I > should share my friend's location with strangers. IMHO the above could and should work even on pure opennet. > > I can't think of an immediately obvious reason why not, since I'm only > revealing their location, not their IP address, but it deserves > further thought. > > Ian. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <https://emu.freenetproject.org/pipermail/devl/attachments/20080612/ab250096/attachment.pgp>
