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Re: [tor-bugs] #7202 [Tor]: Implement ntor handshake or its successor
#7202: Implement ntor handshake or its successor
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Reporter: karsten | Owner:
Type: project | Status: new
Priority: normal | Milestone: Tor: 0.2.4.x-final
Component: Tor | Version:
Keywords: SponsorZ tor-relay | Parent:
Points: | Actualpoints:
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Comment(by nickm):
Replying to [comment:3 mikeperry]:
> Hrmm. I am worried that ntor is even more asymmetric and DoS-vulnerable
How?
Suppose a DoS-ing attacker who takes the minimal effort and just generates
random bits.
In the current case, a server has to respond to a randomly generated
CREATE cell by doing a futile RSA1024 private-key operation and noticing
that the padding's wrong after the RSA decrypt.
With ntor+curve25519, the server has to respond by doing two curve25519
operations and some hashing.
curve25519 is well more than twice as fast as private-key RSA1024 (an
order of magnitude faster on my laptop), so this is *less* "asymmetric and
DOS-vulnerable" than the current RSA approach.
What am I missing?
I agree that solving CREATE-based DoS matters, but it seems like this
isn't a step backwards.
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7202#comment:5>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
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