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). Kind regards, Wiktor [0]: https://tools.ietf.org/html/rfc3161 -- https://metacode.biz/@wiktor _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
