Re: Paper vs. CD Audit Trail

From: Fred McLain <mclain_at_zipcon_dot_net>
Date: Thu Nov 11 2004 - 22:24:24 CST

I've been told voting records retained for 5 years here in Washington.

CDs do *not* last 100 years. There may be a theory or vendor that still
says so but I don't believe it. I have CDs that stopped working, some
from scratches and incidental damage and others through age. Some CD-Rs
just stopped working fairly soon for reasons I can't determine. I'm
willing to guess most of us have seen this. As I pointed out before,
CDs are vulnerable to oxidation. There is a thin layer of sealer over
the top of the CD that prevents this. If there is an imperfection or
damage to this coating, the CD will eventually become oxidized and
inoperable. Pinhole imperfections are not uncommon, and you can't
predict by manufacturer if these occur, since manufacturers of CDs have
changed their production methods fairly frequently.

This problem was covered fairly well in The Register sometime in the
last year, a bit of digging is probably in order.

        -Fred-

On Thu, 2004-11-11 at 18:10, Charlie Strauss wrote:
> voting records retention is 22 months in most states.
>
>
> On Nov 11, 2004, at 11:44 AM, Keith Copenhagen wrote:
>
> > I looked into paper vs. cd as an archive of record.
> > Independent of any clear archive requirement (Other than surviving the
> > 40 days before certification).
> >
> > Best Case Lifetime :
> > Paper – Properly stored acid-free Archival sheet paper has a lifetime
> > of
> > 100 years.
> > CD – Projected lifetime of dyes using accelerated ageing studies is 100
> > years.
> > DVD – No Data, I claim the underlying technologies are close enough to
> > model using CDs.
> >
> > Purchase quality and handling are huge factors.
> >
> > Derating factors :
> > Paper : Commodity Journal Rolls are probably 40-50% the quality of
> > archival.
> > Rolling or Folding, causes some degradation when unrolled
> > (est. 10-20%).
> > Rolling tension can put strong pressure on marks, (unquantified)
> > Data is physical, and degrades over time.
> > I estimate up to 35 years for mostly successful first read, using best
> > practices..
> >
> > CD/DVD : Quality varies widely although the newer faster (50X) are
> > culling out the lowest quality.
> > Proper handling & reading should cause minimal
> > degradation,
> > signed digital data can be migrated.
> >
> > I estimate 20 – 60 years archival life, using best practices.
> >
> > In addition, it is important to consider how to read the medium
> > Paper : Any custom paper roll reader has a very limited lifetime,
> > probably requiring re-invention to read older data. (Speaking of 8”
> > floppies).
> > CD : CD/DVD reader technology has a limited lifetime, (CDs have
> > been
> > around for about 30 years, that may be a one time best-case, although
> > the DVDs may carry the read capability longer than the “market
> > transition” ).
> >
> >
> > http://www.cd-info.com/CDIC/Technology/CD-R/Media/Kodak.html
> > ;: KODAK Writable CD and Photo CD Media. …follow[ing] an Arrhenius
> > model. That model predicts (at the 95% confidence level) that 95% of
> > properly recorded discs stored at the recommended dark storage
> > condition
> > (25°C, 40% RH) will have a lifetime of greater than 217 years.
> >
> > http://desktoppub.about.com/library/glossary/bldef-archivalpaper.htm
> >
> >
>
>
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Received on Tue Nov 30 23:17:28 2004

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