Subject: Re: [p2prg] A possible attack scenario for P2PSIP ?

From: Emil Ivov <[email-masked]>
Date: Wed, 03 Jun 2009 15:52:48 +0200

Hey Anh,

(moving to p2prg since this is where we are discussing the draft)

This is indeed a very important problem. I believe we are addressing it
in section 6 where we talk about routing and data integrity, and then
send sections 7.2.5 and 7.2.6 where we discuss integrity of location
bindings and encrypting content.

Do you think there's something missing or unclear in the above?

Emil

Tien Tuan Anh Dinh wrote:
> Hi all,
> 
> I've just finished reading the draft
> http://www.ietf.org/internet-drafts/draft-irtf-p2prg-rtc-security-01.txt
> 
> It occurs to me that the following attack scenario might be possible:
> 
> 1. Client A registers its location, storing a tuple of the form <id_a, 
> location_a, expiredtime> to a peer P in the DHT overlay (P also 
> represents all replica nodes storing the key id_a)
> 
> 2. Client B searches for A's location, as a result contacts P.
> 
> 3. P decides to not give B the latest A's location. It either sends a 
> out-of-date tuple regarding A's location or says that A is not in the 
> network. A has no way to know or enforce P to behave properly.
> 
> It is a variation of the Denial of Service attack, in which the client A 
> could be made completely unreachable to the other clients.
> 
> Assume the authenticity and integrity of all the tuples, would you say 
> that this is a probable attack? My main concern is what incentives of P 
> in doing this, especially in this P2P-SIP setting. I think this attack 
> depends on the incentives model that encourages clients to act as peers 
> in the DHT overlay. I would love to hear some reasonable explanation of 
> why P would (and would not) engage in this attack.
> 
> Looking forwards to hear your comments.
> 
> Anh.
> 
> 
> 
> 
> 

-- 
Emil Ivov, Ph.D.                               30a rue de la Patrie
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