<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Misbehaving CA proxies present no threat other than revealing of the CA
IPs, as any peer can know immediately if a CA is valid by examining its
certificate or the trust chain of an issued cert. If the list of
trusted roots is distributed w/ the original application, or if the CAs
derive from an OS installed trusted root, it is impossible to
impersonate one without first obtaining the private keys of one of the
CAs.<br>
<br>
That's why I like using a PKI w/ p2p - the only real attack vector is
against the CAs, and there are ways to hide them well (onion routing).
Legal attacks would have to shut down all CAs to take down the network,
which remains possible. I'm not architecting my system for file
sharing, I'm actually building MMORPG infrastructure, so the legal
attack is less of an issue for me, I'm focusing on technical attacks.<br>
<br>
Alen Peacock wrote:
<blockquote
cite="midffe450f90510270845r5d981971m4ee6768795bb7419@mail.gmail.com"
type="cite">
<pre wrap="">On 10/27/05, Kerry Bonin <a class="moz-txt-link-rfc2396E" href="mailto:kerry@vscape.com"><kerry@vscape.com></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap=""> There is also a simple way to harden against this - never publish the CA
IPs to the network, only publish (D[s]HT) a list of current proxies that can
access the CAs. Attacking the CAs then means attacking the proxies, and any
known CA addresses. During an attack, it is possible to republish the proxy
list. If your attackers are following the CA proxy list then you have a
larger problem, but that can also be mitigated by exponentially increasing
the active proxy list, which is simple if this proxy service is part of the
peer protocol suite. This may expose more CA IPs via compromised nodes, but
using a second layer of proxies selected by uptime or other trust metrics
can further limit. It is also possible to use "honey pot" strategies to
identify which proxies are leaking CA IPs. This approach, plus using a
connect protocol that includes DDOS resistance like client puzzles, the
attacker has quite a hard time taking down the CA's. There are more tricks,
these are just some of my favorite...
</pre>
</blockquote>
<pre wrap=""><!---->
Who controls the CA proxies in this scheme? If the "proxy service
is part of the peer protocol suite" (I interpret this to mean that the
proxies are just as untrusted as regular peers, or /are/ the regular
peers), then you now have to worry about malicious and misbehaving
proxies, which could provide an even bigger avenue of attack than the
original set of CAs, no? I'm sure you've thought about this and
probably have some countermeasures to mitigate these effects too, but
I wonder if it doesn't start to look like a rabbit hole?...
Alen
_______________________________________________
p2p-hackers mailing list
<a class="moz-txt-link-abbreviated" href="mailto:p2p-hackers@zgp.org">p2p-hackers@zgp.org</a>
<a class="moz-txt-link-freetext" href="http://zgp.org/mailman/listinfo/p2p-hackers">http://zgp.org/mailman/listinfo/p2p-hackers</a>
_______________________________________________
Here is a web page listing P2P Conferences:
<a class="moz-txt-link-freetext" href="http://www.neurogrid.net/twiki/bin/view/Main/PeerToPeerConferences">http://www.neurogrid.net/twiki/bin/view/Main/PeerToPeerConferences</a>
</pre>
</blockquote>
<br>
</body>
</html>