[Dirvish] hashing backups, timestamping contents

Keith Lofstrom keithl at kl-ic.com
Tue Nov 8 15:32:21 UTC 2011

18 years ago, Stuart Haber filed U.S. patents for a scheme to
timestamp digital documents for legal proof and other purposes.  
The document is hashed, the cryptographic hash is sent to his
company (surety.com).   A file of those hashes is itself hashed,
with the resulting hash printed as an advertisement in a dated
newspaper of record such as the New York Times or the Asahi Shimbun .   

Dr. Haber's first U.S. patents will expire near the end of 2012.

Rsync hashes the files that dirvish backs up, though not with
cryptographic strength.  However, it may be practical to 
cryptographically hash a subset of the files rsync backs up 
daily (using the rsync log files to sense changes), and save
those hashes in another file (again daily), hash that file,
then send those hashes to volunteer hash storage servers at
other sites.  Those servers could hash their daily collections
and forward them to each other, eventually creating literally
"global" hashes which could be published daily in newspapers
of record around the world.

Why do this?  Sadly, some of the open source code we develop
(or the public domain inventions I disclose) is stolen and
patented by trolls.  Proving a public disclosure as prior art
(to invalidate the patent) can be difficult.  If we put our
inventions and code and ideas on the web, that can be a
public disclosure, but it is not legally timestamped with
proven provenance so it can be used in court.  Perhaps,
with this process, it will be easier to prove the priority
of our public disclosures and help fight these patents.

Dirvish is a good platform to add this feature to.  More
likely, the dirvish process can call another program using
the post-process directive.  That additional program does
the cryptographic hash and sends it to other sites.  This
can be done on the backup machine after backups are complete. 
Perhaps our community could begin the development of a program
for this, and deploy it after Surety's first patents expire.


Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs

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