Nonetheless, without a layer of mixnet routing, various attacks on freenet, mostly correlation attacks, are far too easy for us to be comfortable.
On Wed, Dec 07, 2005 at 05:01:30PM +0000, Michael Rogers wrote: > Hi Joe, > > Onion routing refers to the fact that each Tor message is wrapped in > several layers of encryption, like the layers of an onion. The sender > chooses the route in advance and encrypts the message once for each node > along the route, starting with the last. Each node removes a layer of > encryption to reveal the address of the next node, and forwards the > message to the revealed address. > > Onion encryption is supposed to prevent the node next to the sender and > the node next to the recipient from colluding to discover whether the > sender and recipient are communicating, because the nodes can't tell > they're handling the same message. However, in a low-latency system like > Tor it may be possible for nodes to tell whether they're part of the > same route by comparing the timing and throughput of the routes they > belong to, so the benefit of onion encryption for low-latency > communication is debatable. > > The biggest problem with onion encryption is key distribution: the > sender needs to know the public key of every node along the route in > order to onion-encrypt the message. Tor handles this by using a small > number of directory servers to distribute keys, thus creating a central > point of failure. > > Freenet doesn't use onion encryption, so nodes along the route know > they're handling the same message, but this isn't as much of a problem > in Freenet as it would be in Tor - as Ian pointed out, Tor uses a > client/server architecture so it's easy to distinguish the sender and > recipient from nodes that are merely forwarding the message, but Freenet > is peer-to-peer and therefore it's hard to tell whether a request > originated from the previous node or whether it was forwarded on behalf > of someone else. > > There's a longer (though by no means comprehensive) survey of > anonymising networks in my literature review: > > http://www.cs.ucl.ac.uk/staff/mrogers/literature-review.html > > Cheers, > Michael > _______________________________________________ > Tech mailing list > Tech at freenetproject.org > http://emu.freenetproject.org/cgi-bin/mailman/listinfo/tech -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/tech/attachments/20051207/b5fac16d/attachment.pgp>
