Slightly OT - i need the proper wording for a signed document

Wiktor Kwapisiewicz wiktor at
Fri Nov 2 12:20:43 CET 2018

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:

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,



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