PDF/signature

Referenzen

http://askubuntu.com/questions/87419/how-can-i-add-text-and-images-for-example-a-signature-to-a-pdf

http://askubuntu.com/questions/147379/how-do-i-digitally-sign-a-pdf

http://superuser.com/questions/1050032/digitally-sign-latex-pdf-document-with-ca

https://answers.acrobatusers.com/How-do-I-create-a-PDF-file-that-can-be-digitally-signed-q82444.aspx

http://tex.stackexchange.com/questions/51090/how-do-i-create-a-pdf-file-that-can-be-digitally-signed