[p2p-hackers] Byzantine Quorum Systems

[Brad Neuberg]

Nick, I've been reading over the papers on your website and want to know 
your opinion of how well byzantine quorum systems work under the following 
conditions:

* A majority of the nodes have a half-life of about an hour (i.e. every 
hour half the nodes in the p2p system leave).  A large number of nodes 
never rejoin the system again.
* The system has high latency (i.e. it is running over the public Internet)
* A majority of the nodes are NATed or firewalled, depending on other nodes 
to relay requests.

My understanding of byzantine quorum algorithms are that they break down 
under the kinds of conditions found in large-scale, P2P systems, which have 
very high node churn and high latency, described above.  They seem to be 
focused on very stable or LAN type networks.  Is this a correct 
assumption?  If it is, it seems that byzantine quorum algorithms need to be 
refocused on the kinds of networks that we are dealing with today, rather 
than LAN centric networks or networks of very stable servers on the public 
Internet.

Best,
   Brad Neuberg

At 07:22 PM 2/21/2005, you wrote:

> > "Also, a decentralized scheme such as in
> > Kazaa has no availability problems but lacks integrity, since Kazaa is
> > plagued with many fake files. Clearly, decentralization is an unsolved
> > issue that needs further research."
>
>Perhaps this is ironic, but a good solution is protocol-enforced property
>rights.  Specifically, we should treat names crossing trust boundaries as
>property, and securely agree across trust boundaries on who owns what names,
>as described in
>
>"Secure Property Titles with Owner Authority",
>http://szabo.best.vwh.net/securetitle.html
>
>Nick Szabo
>_______________________________________________
>p2p-hackers mailing list
>p2p-hackers at zgp.org
>http://zgp.org/mailman/listinfo/p2p-hackers
>_______________________________________________
>Here is a web page listing P2P Conferences:
>http://www.neurogrid.net/twiki/bin/view/Main/PeerToPeerConferences

Brad Neuberg, bkn3 at columbia.edu
Senior Software Engineer, Rojo Networks
Weblog: http://www.codinginparadise.org

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