CDR: auditable gaming PRNGs (Re: PRNG server) (fwd)

[Jim Choate]

---------- Forwarded message ----------
Date: Sun, 3 Sep 2000 11:49:16 -0500
From: Adam Back <adam at cypherspace.org>
Reply-To: cypherpunks at ssz.com
To: bill.stewart at pobox.com
Cc: petro at bounty.org, cypherpunks at cyberpass.net
Subject: CDR: auditable gaming PRNGs (Re: PRNG server)


Seems to me you can do better with a gaming server.  If the gaming
server servers RNGs in a sequence such that each sample in the
sequence can be verified, they don't need to trust the server; or at
least there is an audit function.

Eg. say that the server publishes subsequent pre-images in a
hashchain.

h_0 
h_{i+1} = h_i

and the server computes h_i values up to i = 10^8 and then publishes
them starting with h_{10^8}, h_{10^8-1}, ...

Then anyone can verify that the random number is the preimage of the
previous random number.

You do something similar with a more efficient (log(n)) auditing
function with merkle authentication trees.

If they aren't doing this someone should clue them in.

Adam

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