On Wed, Feb 20, 2008 at 6:40 PM, Tony Finch <d...@dotat.at> wrote: > On Tue, 19 Feb 2008, Michael G Schwern wrote: > > > It's not like we haven't had have secure, cheap digital signature > technology > > for decades now. It's not like everyone with a PC, scanner and printer > > doesn't have the technology to forge a handwritten signature. > > Handwritten signatures are a record of the assent of the signer.
Ah, but how can you tell from a bunch of pixels on the screen/a bunch of bits in a PDF file whether they're the result of scanning in a handwritten signature that shows from a signer giving his assent, or whether they're the result of someone having fun with their graphics tablet and Photoshop? The problem is that a forged signature does *not* record the assent of the purported signer, and that you can't tell them apart if all you have is a digital document that was supposedly scanned in from a piece of paper. And if you can't tell whether a bunch of bits is a scanned-in handwritten signature or not, you might as well not include that bunch of bits in the file since it's not adding any semantics. Cheers, -- Philip Newton <philip.new...@gmail.com>
