[p2p-hackers] References for using hashes as unique identifiers?

[Adam Back]

Re rediscovery, eternity USENET [1] (1997) also used location
independent URLs.  The URLs where defined on non-existant TLD
.eternity; the implementation used USENET as an anonymous broadcast
(remailer -> USENET) system to distribute content.

I Note the Xanadu folks also planned a USENET style flood ... same
again, except my reason for using USENET was it's own censor
resistance arising from it's distributed nature, plus existing
anonymous broadcast support (remailers -> USENET).

The actual _URL_ was hashed to arrive at a document tag (rather than
the document being hashed).

The original version of a document could also optionally contain a
signing key, and subsequent versions could be updated using that key.
The user could therefore prevent coerced revision by signing and then
destroying the signing private key.

Also had support for encrypted content so that only readers in a group
could read that content.

On top of that my thoughts (not implemented) for later features
included some distributed / p2p system to allow eternity stores to
talk to each other so that:

- they could reach data that they did not see, 

- and so that the document space could scale beyond what single nodes
could hold without manual partitioning -- by implementing random
cache-replacement policy, and having nodes able to resolve data in
each other's caches.

Note that latter point I call over-cacheing, and is something I have
not seen in p2p systems to date -- aim for each node to fill up it's
storage space with a random stripe of data -- makes optimal use of
storage which is cheap and plentiful, and trades off extra storage for
faster, more local, less slow, multi-network hop DHT style lookups.


I see Zooko / others also discussed using self-authenticating URLs,
another system doing that was wax / eternal resource locator.

Adam

[1] http://www.cypherspace.org/eternity/
[2] http://www.cl.cam.ac.uk/ftp/users/rja14/wax.ps.gz
[3] http://www.cl.cam.ac.uk/ftp/users/rja14/erl3.ps.gz
[2,3] http://www.cl.cam.ac.uk/ftp/users/rja14/

On Sun, Mar 07, 2004 at 04:49:19PM -0800, Mark S. Miller wrote:
> I believe the concept originated at Xanadu around 1990 or so, but was never 
> implemented or published. AFAIK, it was implemented for the first time at 
> Electric Communities as the "Repository" -- a component of EC Habitats. This 
> was perhaps around 1995. Jim McCoy then took the idea to MojoNation, which 
> is how the rest of the world became exposed to it.
> 
> Of course, being an obvious idea, it may have been rediscovered many times, 
> so it wouldn't surprise me if there were other independent historical 
> sequences. If anyone knows any, I'd be curious to hear of them. Thanks.