Friday, November 18, 2011

Non-Repudiation is a very old art


Updated: The video recording is available here.

During the ONC Annual Meeting I absolutely enjoyed Jay Walker Keynote: “Achieving Big Changes”. A wonderful history of technology starting with a clay device from 2000 BC that was used as a receipt.

I think it is the white cone on the far right in this picture from the Wired article on Jay Walker. This is a cone of pottery with markings on it. The exerpt for this picture identifies it "a truly ancient storage device, a Sumerian clay cone used to record surplus grain."

I really hope that this webinar is available for replay as it is fantastic lesson in where we get much of what we have today. In fact I think that he outlines very well many of the requirements that we still struggle to achieve with modern technology. Jay went on to explain much ancient artifacts role in advancements, artifacts from his own collection.

The clay device that Jay showed is not unlike the ‘Cuneiform tablet’ shown at the Metropolitian Museum of Art. The ‘technology’ at the time allowed for the creation of a receipt that was not possible for the holder to modify, or at least any changes would be obvious. The use-case, as Jay explains, was to record the amount of surplus grain that a farmer had deposited so that later the farmer could get back the grain or money it was worth. The receipt writer would make marks on clay, fire the clay to make it permanent, and give the receipt holder the hardened-pottery. Later the farmer could present the pottery and the merchant would be able to tell that it is legitimate and not changed.

So these 4000 year old devices are ‘the’ earliest samples of non-repudiation, the key characteristic that people look to for electronic signatures (Digital Signatures). Jay pointed out that not only are these some of the oldest examples of writing, but also non-repudiation. This shows how 'need' and 'value' drove the invention of these pottery based receipts. This same concept we look for in electronic signatures; of being something hard to create, hard to falsify, and verifiable. It also shows that the technology scales with the value it is protecting.