Re: Alternatives to a single bar code

From: Alan Dechert <alan_at_openvotingconsortium_dot_org>
Date: Wed May 05 2004 - 11:01:52 CDT

David and Karl:

> On May 5, 2004, at 5:22 AM, Karl Auerbach wrote:
> > multiple bar codes could lead to reader misreads...
> > individual bar-codes from different ballots be scanned as if they were
> > from the same ballot.
>
> Right-O. One barcode is better for this type of reason.
>
> > 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.
>
> This is not quite true. Well, obviously if we use Karl's standard of
> "worry when we get to 10% of theoretical limit" we're there. But that
> standard makes more sense for quantities--say bandwidth--that pretty
> much expand monotonically. Elections don't.
>
Yes

> The demo merely used an inefficient encoding. You can calculate the
> optimal encoding for any election using my election-entropy.py tool.
>
Thanks for doing that. I'd like to see a generalized encode/decode routine.
This would truly be part of the production system so it's not urgent at this
point.

> We can fit the demo data in about 35-40% of the space we actually used.
> For the demo data, 53 bits is what we need. That leaves enough room
> for a crypto signature and globally-unique ballot ID to be added (and
> even some small ECCs, beyond those inherent in Code128).
>
Right. We need to decide what all goes in the barcode.

> I second Alan's opinion that the data requirements are an empirical
> question. If 99% of elections can get by with the simpler 1-D barcode,
> we should stick with simple (for most jurisdictions). If lots of
> elections need 2-D, we should start working towards that.
>
Sounds good.

> So first thing would be for someone to locate ONE historical election
> that can't fit in Code128. I am unaware of one. For example, the
> California Special Gubernatorial contest fits fine. Chicago judicial
> retentions with 40 Judges and a handful of Congresscritters, Senators,
> initiatives, etc fit fine (assuming a moderate number of candidates for
> each contested race).
>
I asked for that a number of times. San Francisco might be a good place to
look.

> I'm not particularly a FAN of 1-D codes like Code128. Less so than I
> think Alan is (because he's too fond of the el-cheapo CueCats he
> found). I'm not an enemy of 1-D either. But before we conclude that
> Code128 will inevitably hit a storage limit, lets find some concrete
> evidence for that.
>
> *Keeping in mind* that elections, unlike bandwidth, HDD size, CPU
> speed, or spam, don't follow a Moore's Law style monotonic curve.
> Instead, the range of sizes that exist in the last half dozen decades
> is pretty much the same as what we expect to find in the next half
> century too.
>
Right. This is mainly due to redistricting. When the population grows, you
don't get another representative on the ballot. You get another district.
So while the ballot counting process has more to it as population grows,
individual ballots still have only one U.S. representative. "Direct
Democracy" brings us a lot of propositions, initiatives and such on the
ballot, but this is not necessarily a permanent fad. We may see more of
this but we may also see less. I think it's related to a perception that
office holders have been ineffective.

Alan D.

==================================================================
= The content of this message, with the exception of any external
= quotations under fair use, are released to the Public Domain
==================================================================
Received on Mon May 31 23:17:14 2004

This archive was generated by hypermail 2.1.8 : Mon May 31 2004 - 23:18:15 CDT