[p2p-hackers] Altnet goes after p2p networks with obvious patent

Bryan Turner bryan.turner at pobox.com
Fri Jan 21 17:43:34 UTC 2005

	Another note regarding content hashing..  I'm reviewing the CFS [1]
paper and it specifically states:

	"CFS authenticates data by naming it with .. content hashes .. The
use of content hashes to securely link together different pieces of data is
due to Merkle [2] .."

	The Merkle reference is 1987, regarding digital signatures of a
document.  Not sure if it suggests using the signature as a handle to the
document, which appears to be the claim of this patent, but the CFS authors
seem to think so.

bryan.turner at cisco.com

[1] http://www.pdos.lcs.mit.edu/papers/cfs:sosp01/cfs_sosp.pdf
[2] Merkle, R. C. A digital signature based on a conventional
    encryption function.  Advances in Cryptology - CRYPTO '87
    (Berlin, 1987), C. Pomerance, Ed., vol. 293 of Lecture
    Notes in Computer Science, Springer-Verlag, pp. 369-378

-----Original Message-----
From: p2p-hackers-bounces at zgp.org [mailto:p2p-hackers-bounces at zgp.org] On
Behalf Of Ian Clarke
Sent: Tuesday, January 11, 2005 2:17 PM
To: Peer-to-peer development.
Subject: [p2p-hackers] Altnet goes after p2p networks with obvious patent


It seems that Altnet is finally going after file sharing networks with its
laughably obvious patent on requesting files by a hash of the file's
contents (fortunately Freenet's developers are predominantly European, and
thus are largely immune to this).

IIRC this patent was filed in 1997.  I think it is very important that those
attacked challenge this patent head-on, either by claiming it is invalid due
to being obvious, or finding prior art.

I vaguely recall the last time I researched this that there was prior art
from as early as 1990, I think it was Project Xanadu (http://xanadu.com/).

Can anyone provide specific pointers to good examples of prior art?  If
Altnet succeeds in extorting any money out of these P2P companies it will
only serve to encourage them to attack others.


Founder, The Freenet Project	http://freenetproject.org/
CEO, Cematics Ltd				http://cematics.com/
Personal Blog					http://locut.us/~ian/blog/

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