dss-x — archive

[Andreas Kuehne]

Hi Leonard, good to have you on the list ! >> I would like to distinct he pretty printing stuff mentioned above and >> the crypto content made visible and hopefully computer processable from >> a printed instance. >> > We've seen a couple of attempts at this as well - but none that would > actually work on complex document types like those that can be > represented by > PDF. The problem, of course, is the canonicalization of the > content. How can > you recreate the electronic content "byte for byte" to match the > data stream > that was fed into the hash originally? Don't worry, the 2D bar code works quite well ! The conductors on the train scan the code 'on the fly' and I've seen no scanning problems, even at 250 km/h. I guess there is a bunch of travel data within the bar code and the human readable part doesn't needs scanning. Anyway : This works quite well ! I'm not quite familiar with Konrad's use case, maybe he noticed the problems you mentioned ... [..] > >> If there is a signature field within the >> given PDF document, we can do the crypto stuff on it. That's it ! We >> don't need to care about all the PDF layers, dictionaries, versions of >> forms ... >> > Oh, but were it that simple ;). > > What about documents you wish to sign that don't have the > necessary fields > already present? What about multiple signature workflows? What > about author > vs. certifying signatures (or even more interesting, a document > containing > both!)? Oh yes, these are all the problems I like to shy away from ! Remember the 'please sign here ...' example : - The required fields MUST be present ! - The request must include some information about the signature to sign ( well, that's a common problem with XMLDSig ). We'll have to find a way to identify the intended field for signing. The DSS implementation should care about things it's designed for : Signing et al. Leave form handling and PDF creation to the PDF experts ! Greetings Andreas ___________________________________________________ Andreas Kühne phone: +49 177 293 24 97 mailto: kuehne@trustable.de Trustable Ltd. Niederlassung Deutschland Ströverstr. 18 - 59427 Unna Amtsgericht Hamm HRB 5868 Directors Andreas Kühne Heiko Veit Company UK Company No: 5218868 Registered in England and Wales ----- Ende der Originalnachricht ----- ___________________________________________________ Andreas Kühne phone: +49 177 293 24 97 mailto: kuehne@trustable.de Trustable Ltd. Niederlassung Deutschland Ströverstr. 18 - 59427 Unna Amtsgericht Hamm HRB 5868 Directors Andreas Kühne Heiko Veit Company UK Company No: 5218868 Registered in England and Wales