1994-12-08 - cut & choose

Header Data

From: Alex Strasheim <alex@omaha.com>
To: cypherpunks@toad.com
Message Hash: 8b23865cfae8e91165bd6bd7e5d9483862fbae835105220905de989f9266a9d7
Message ID: <199412082010.OAA00148@omaha.omaha.com>
Reply To: N/A
UTC Datetime: 1994-12-08 20:09:51 UTC
Raw Date: Thu, 8 Dec 94 12:09:51 PST

Raw message

From: Alex Strasheim <alex@omaha.com>
Date: Thu, 8 Dec 94 12:09:51 PST
To: cypherpunks@toad.com
Subject: cut & choose
Message-ID: <199412082010.OAA00148@omaha.omaha.com>
MIME-Version: 1.0
Content-Type: text


-----BEGIN PGP SIGNED MESSAGE-----

In Applied Cryptography, Schneier describes digital cash protocols that
depend on the cut and choose method:  Alice prepares 100 anonymous money
orders for $100, sends them all to the bank, which opens all the envelopes
except one picked at random.  If the 99 envelopes checked have money
orders for $100, then the bank is confident that the one they sign blindly
will be for $100 as well. 

Chaum's system uses different keys for different denominations.  Alice 
only sends one envelope, and the bank uses its $100 key to sign it.

I don't understand why anyone would use the cut and choose protocol over 
denominated keys.  Chaum's method seems a lot cleaner to me and more 
secure.  It obviously uses less bandwidth.  What am I missing here?

==
Alex Strasheim | finger astrashe@nyx.cs.du.edu
alex@omaha.com | for my PGP 2.6.1. public key

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQCVAwUBLudoHxEpP7+baaPtAQFIiwQAsCc/TYI/cgJyGf6AtykBGgu+qJJ+peM6
/IYXnUzrIeFLx54nRjsUOUFYJs6Uu3vu6s2BRbd2/YIJVaY6/kP4HO0zuMhqFn2z
4eddRverUeH59IZgZ+4Va4/rgfn5hRdNSOgNinIyk0aRsa8ulR+cmJdUYqggHgd5
w2dxkAtDSGM=
=fzJT
-----END PGP SIGNATURE-----




Thread