Re: Alternatives to a single bar code

From: Karl Auerbach <karl_at_cavebear_dot_com>
Date: Wed May 05 2004 - 04:22:35 CDT

On Wed, 5 May 2004, Steve Chessin wrote:

> The nice thing about multiple bar codes is that they scale.

I'm concerned that the presence of multiple bar codes could lead to reader
misreads.

But more importantly, I'm concerned about attacks that could occur should
individual bar-codes from different ballots be scanned as if they were
from the same ballot.

This is why I prefer one bar code that contains all the data (that bar
code would be replicated for protection against damage, but it would be
the same bar code.)

I don't see any hope that we will be able to stay within the data limits
of the 1 dimensional bar codes - we are already pushing the limit, even
without a digital signature message digest or end-to-end check-code. But
the 2-D codes (e.g. PDF417) can hold about 2kbytes - about 50 to 100
times what we are getting out of the current 1D EAN128C bar code. The
price for a usable 1D handheld scanner is roughly $150, a 2D model costs
about $50 more.

                --karl--

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Received on Mon May 31 23:17:14 2004

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