[FoRK] PersonalWeb patents "unique" hashes of content

Ken Meltsner meltsner at alum.mit.edu
Tue Sep 18 18:48:27 PDT 2012

On Tue, Sep 18, 2012 at 8:41 PM, Stephen Williams <sdw at lig.net> wrote:
> Content addressable storage == hashtable.  Earliest use of a hash table?
> 60's at the latest.
> Actual CAS granularity hash tables:
> http://doc.cat-v.org/plan_9/4th_edition/papers/venti/
>> The Stanford Archival Vault [2] is a prototype archival repository
>> intended for digital libraries. The archive consists of a write-once log of
>> digital objects (files) and several auxiliary indexes for locating objects
>> within the log. Objects are identified by the hash of their contents using a
>> cyclic redundancy check (CRC).

Or 'rsync' -- version 1.0 released in 1996.  The first of the patents
was applied for in 1997, so I suppose a "first to invent" rule might
give them precedence.

Heck, I had disclosures on a content hash-based access control system
in 1996, so I suspect others had similar ideas even earlier.  There is
a distant memory of a European company which used cryptographic hashes
for identifiers of content to be distribution around that time.


Ken Meltsner

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