[freenet-dev] Alpha, Darknet routing, et al.

[Matthew Toseland]

On Friday 01 February 2008 17:00, Robert Hailey wrote:
> 
> On Jan 31, 2008, at 11:03 AM, Robert Hailey wrote:
> 
> >> How do you authenticate the routed pings, to prevent an attacker from
> >> replying on behalf of another node?
> >
> > Excellent question. Surely the "true/false" response of present is
> > woefully inadequate. Since we have a direct connection to the peer
> > that we are pinging a challange-and-response mechanism is easy, no?
> >
> > Consider node "B" who is between "A" & "C" (A-B-C). He tells "C" a UID
> > & Secret [a randomly generated long?], and "C" stores that secret/uid
> > as part of our peernode record. Node "B" then sends node "A" a routed
> > ping with the same UID, and if node "A" returns the pong with the
> > correct secret it is a success.
> 
> I was supposing that these pings would be sent at less-than-max htl  
> (since we are not searching the network but doing a connectivity  
> test), but wouldn't that possibly allow an attacker to learn who your  
> peers are?
> 
> That is, if an attacker has a node connected to your node and your  
> peers node, he could put together the ping from yours, the reply from  
> your peer, plus the fact that the reply comes from a node of the same  
> location as the ping, and be reasonably sure he is your peer. Whereas  
> with the probabilistic decrement at the real maxHTL, they could not be  
> nearly so sure.

He can already know this, because of swapping.
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