[p2p-hackers] P2P or centralized
Salman Abdul Baset
salman at cs.columbia.edu
Thu Aug 14 21:12:03 EDT 2008
>>>> Nodes need to connect to a central server to get their identity signed by a
>>>> central server. This must happen to prevent Sybil attacks. A bootstrap server
>>>> can be co-located with this authentication server.
>>> That's one thing that's bothered me with a lot of discussions of P2P.
>>> At the end of the day, real-world p2p systems utterly depend on
>>> reliable, realtime access to centralized components. Successful systems
>>> recognize and exploit this.
>> BitTorrent, eMule, Skype are examples of successful distributed systems.
>> They may not be 'purely' distributed, but work reasonably well.
>>> Usability, security, decentralization. Pick any two.
>> For Skype, can we pick all three? :)
> Skype isn't decentralized. They have central bootstrapping, central
> authentication, central billing, etc. If Skype says you don't talk, you
> don't talk. If Skype blows up, you don't talk. And as happened last
> year, if their pointless rendezvous mesh gets destablized due to massive
> reboots, you don't talk for a long time.
If MSN, or Yahoo says don't talk, then you don't talk either...
> AIM, ICQ, or MSN are all far bigger than Skype; have they *ever* gone
> down that long?
> Anyway, just pushing back on the religion that P2P has developed. It's
> fun. It's sexy. It's really hard. But it's often pointless.
The advantage of p2p is that it reduces cost of entry in a certain market
space. No one denies that anything p2p cannot be done central. However,
sometimes economics justify using p2p as a solution. And in Skype's case
experience gained from Kazaa was no doubt helpful.
To completely rule out non-server p2p as a possible solution for a problem
is also naive, and amounts to a no-p2p religion.
My point is that take a hard look at the problem and the economics, and
pick a solution that has the best cost/benefit ratio. If the solution is
p2p, so be it.
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