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Re: one less onion skin
I'm not sure if this really happens, but if you have a connection open
to an OR and a new circuit is required through it,
couldn't ORn-1 send a CREATE_FAST to ORn?
Steve Southam wrote:
Is it because the ORs don't know where they are in the circuit?
Of course OR3 knows it's at the end, but the others either recognize
I agree that not using k_1, d_1 would allow OR1 to determine that they
are the first node in a circuit. However, Tor clients already leak
this information. The key agreement with OR1 is done using a
"CREATE_FAST" command rather than a normal "CREATE". So, once an OR
receives a "CREATE_FAST" it knows its position in the circuit. (it
might be that Tor clients which are also onion routers themselves do
not send "CREATE_FAST"... I am not sure)
So the question is, if we have already leaked this information, are we
wasting CPU cycles doing AES with OR1?