On Fri, 2 Nov 2018 12:20:43 +0100, Wiktor Kwapisiewicz wrote: > On 02.11.2018 10:53, Stefan Claas wrote: > > Simply one can use a time stamping service, based on blockchain > > technology. I can then time stamp the .pdf. and put also a > > statement in the .pdf that the file is timestamped and don't must > > worry in the future if one MITM would try (and why?) to alter my > > documents. > > PDFs can be also timestamped when signing with standard RFC 3161 [0] > timestamping service. > > Here's one example: > > https://support.globalsign.com/customer/en/portal/articles/2361790-add-timestamp-server---adobe-acrobat > > But there are numerous free RFC 3161 timestamping services. > > Of course that's not the same as blockchain, but it's already > supported by numerous tools (like Adobe Acrobat).
> [0]: https://tools.ietf.org/html/rfc3161 Hi Wiktor, thanks a lot! Now this is awesome... i just timestamped my already signed .pdf with Adobe Reader DC and this does not invalidate my qualified signature, when saving the document again! :-) I must admit i did not know this. Regards stefan -- https://www.behance.net/futagoza https://keybase.io/stefan_claas _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
