Digital signing of documents (non-qualified digital signature)

Microsoft Office

1. When signing a document created in Microsoft Office, for example a Word document (*.docx), please select the File option..

   

2. In the window that appears, click on Protect Document and select the option Add a Digital Signature.

   

3. During this phase, you can sign the document by selecting the Sign option.

   

4. When you receive the success message, click on OK to continue.

   

5. Once the document is digitally signed, it will include the record of the Author's identity. In case the document is later edited by third parties, the digital signature will be "removed". This feature allows you to assess the integrity of a document.

   

Acrobat Reader

1. On the Edit menu, select the Preferences option.

   

2. On the Signatures section, go to Identities & Trusted Certificates and click on More.

   

3. Select your digital certificate. Click on Usage Options and select Use for Signing. Close the window to continue.

   

4. To digitally sign a document, open it (*.PDF).
5. Click on the Tools tab and select the Certificates option.

   

6. Select the option Digitally Sign.

   

7. Read the instructions and click on OK to continue.

   

8. Select the area in the document where you wish to place your signature.

   

9. A window will appear. Please select your Digital Certificate. Click on Continue.

   

10. Preview the signature and block the document, if you wish, by selecting the option Lock document after signing. Click on Sign to digitally sign the document.

    

11. Choose the directory where you wish to save the signed document and click on Save to finalise the process.

    

12. Your document is now digitally signed, however, Acrobat Reader will inform you that the signature is not valid. This alert is generated because Sectigo (Certifying Authority) is not part of the Adobe Approved Trusted List.

    To correct this, it is possible to add Sectigo to your device's Adobe Approved Trusted List. For that purpose, click on Signature Panel.

    

13. Right-click on Document Locked by Signature and then select Show Signature Properties.

    

14. You will see that the document is intact and that it was not modified since it was digitally signed. However, Acrobat Reader's alert will remain.
15. Click on Signature Properties.

    

16. Click on Show Signer’s Certificate.

    

17. Go to the Trust tab, select GEANT Personal CA 4 and click on Add to Trusted Certificates.

    

18. Confirm that you would like to continue the operation by clicking on OK.

    

19. Select the option Use this certificate as a trusted root. Click on OK to continue.

    

20. According to Acrobat Reader, the digital signature is now valid. Remember that this is a mere aesthetic detail. Previously, the document was already digitally signed by a valid CA (Sectigo), with a note saying The document has not been modified since this signature was applied.