A process of signing documents comprising the following steps: (a) generating a document identification (DID) from a digital copy (DOC DC ) of a document to be signed by at least one signatory; (b) encoding the document identification (DID) into one or more watermarks (WM; WM SA ; WM A ); (c) producing a hard copy (DOC HC ) of the document to be signed incorporating the one or more watermarks (WM; WM SA ; WM A ); (d) reading the one or more watermarks (WM; WM SA ; WM A ) provided on the hard copy (DOC HC ) of the document using an optical reader device (ORD; 10); (e) decoding the document identification ([DID] ENC ) encoded into the one or more watermarks (WM; WM SA ; WM A ) read by the optical reader device (ORD; 10); (f) associating the hard copy (DOC HC ) of the document to be signed to the digital copy (DOC DC ) of the document to be signed based on the decoded document identification ([DID] DEC ); (g) signing of the hard copy (DOC HC ) or the digital copy (DOC DC ) of the document by the at least one signatory using a digital signing device (DSD; 10); (h) obtaining, based on authentication of the at least one signatory using the digital signing device (DSD; 10), signatory information (K SIG ) unique to the at least one signatory using the digital signing device (DSD; 10); and (i) generating a digital signature (SIG) of the digital copy (DOC DC ) of the document based on the decoded document identification ([DID] DEC ) and the signatory information (K SIG ), and applying the digital signature (SIG) to the digital copy (DOC DC ) of the document to produce a digitally signed copy (DOC SIG ) of the document. (a) generating a document identification (DID) from a digital copy (DOC DC ) of a document to be signed by at least one signatory; (b) encoding the document identification (DID) into one or more watermarks (WM; WM SA ; WM A ); (c) producing a hard copy (DOC HC ) of the document to be signed incorporating the one or more watermarks (WM; WM SA ; WM A ); (d) reading the one or more watermarks (WM; WM SA ; WM A ) provided on the hard copy (DOC HC ) of the document using an optical reader device (ORD; 10); (e) decoding the document identification ([DID] ENC ) encoded into the one or more watermarks (WM; WM SA ; WM A ) read by the optical reader device (ORD; 10); (f) associating the hard copy (DOC HC ) of the document to be signed to the digital copy (DOC DC ) of the document to be signed based on the decoded document identification ([DID] DEC ); (g) signing of the hard copy (DOC HC ) or the digital copy (DOC DC ) of the document by the at least one signatory using a digital signing device (DSD; 10); (h) obtaining, based on authentication of the at least one signatory using the digital signing device (DSD; 10), signatory information (K SIG ) unique to the at least one signatory using the digital signing device (DSD; 10); and (i) generating a digital signature (SIG) of the digital copy (DOC DC ) of the document based on the decoded document identification ([DID] DEC ) and the signatory information (K SIG ), and applying the digital signature (SIG) to the digital copy (DOC DC ) of the document to produce a digitally signed copy (DOC SIG ) of the document. <EOS>