Timestamping

Regardless of the medium, what is most important is the preservation of information. In Quebec, according to An Act to Establish a Legal Framework for Information Technology, RSQ, c C-1.1, to argue in evidence, it must be shown that the integrity of the information has been maintained throughout its life cycle. In other words, the content of the printed version must remain identical to its original, digitally signed, electronic version to maintain its legal validity. Conversely, the same principle can be applied, for example, to the original paper version that is digitized and sent by email. The whole of the information must be preserved and we must ensure that it has not been falsified or altered by using protective measures such as a digital signature, an electronic seal, time stamping, etc. Such measures assure that any changes made to the document can be traced.

A signed document can be marked up but cannot be easily altered. If a digitally signed document were to be altered, the digital signature would be removed from the file, thus rendering the document a copy of the original. For example, in paper form, a wet signature original can be photocopied, thus creating a copy of the original and this copy can be easily modified and altered. The same is true for an original electronic PDF with a digital signature. It can be “reprinted” as a PDF and the new document then becomes a copy of the original. This copy can be altered but, for the recipient, it is a copy since the digital signature is no longer part of the PDF.