A quick guide to digital signatures

This quick guide has been written in the context of SLD signing.

Digital signature with Adobe Acrobat Professional 8 (on Windows)

There are three ways of doing it. Acrobat Professional lets you "Certify a document", "Place a signature" and "Place a signature so that others can sign with Acrobat reader" ( i.e. by creating a Reader Enable pdf file). The latter is the CERN ROC preferred choice.

Importing your certificate

A digital ID appeared to be already under "Security Settings" in the "Advanced" menu. As the "storage mechanism" is "Windows Certificate Store" I assume that importing my certificate in Internet Explorer did the trick. I also managed to add my certificate (p12 file) using the "Add ID" option of the same menu ("Security Settings" under "Advanced"). However nothing was appearing under the the "Manage trusted identities" under the "Advanced" menu. So I had go back to "Security Settings" and export my identity to a file (did it as .p7c file) so that I could then reimport it as a contact for the "Manage Trusted Identities" menu (if you find an easier way, please edit the page or let me know in some way or another!). After I was known to the "Manage Trusted identities" menu, I could set the trust for my own certificate.

Certification

One could choose to certify with a visible signature or without a visible signature. I personally prefer visible signatures. In any case, this becomes completely irrelevant, once you read the next paragraph.

Certification should be the correct way to do it, as it certifies the document and does not allow any further modifications to it, but only signatures (at elast so the option says). Unfortunately when I tried it did not allow any further signature either, so I put it here only for the sake of completeness, with the hope that one day it will work.

Signing a pdf document

Under the "Sign" menu, choose "Place signature". You then have to drag the mouse so as to highlight the area in which a visible signature will be placed, a small window appears with the details and preview o f your signature. Once you click ok, the signature is visible in the document.

Creating and signing a Reader Enabled pdf document

You should reader enable the pdf before signing as described in this paragraph. This is achieved by clicking on the "Enable Usage Rights in Adobe Reader..." menu under "Advanced".

Digital signature with Adobe Acrobat Reader 7 or 8 (on Windows and Linux)

This is only possible if the person who created the pdf document made it "Reader Enable" using the "Enable Usage Rights in Adobe Reader" menu.

If it has been done, then under the "Sign" menu you should have a "Place signature" option. If you cannot see the option, but just a "Preview Document" and "Validate All Signatures" under the "Sign" menu under the "Document" pull down menu it means that the pdf is not reader enabled (or possibly that you are not using Acrobat reader 7 or 8 but an older version).

Importing your certificate

A digital ID appeared to be already under "Security Settings" in the "Document" menu in my case. In general digital IDs in the form of p12 files are added and managed using the "Security Settings" of the "Document" menu. It is also possible to manage digital IDs in the form of roaming profiles, or hardware tokens.

Digital signature with Open Office (on Windows and Linux)

Signing with Open Office requires the document to be saved in the open document format (.odt), so once it is signed it cannot be read by Microsoft Office anymore.

Importing your certificate

You should import your certificate using a recent version of any of Thunderbird, Firefox or the Mozilla suite. Once this is done, the certificate should automatically appear in OpenOffice when you try to sign a document.

Signing the document

Just use the "File" menu and click on "Digital signatures". A window opens to tell you who has signed the document already. If you want to add your signature you should click on the box labeled "Add...". The signature is not physically visible on the document. To view the existing signatures the process is the same. The online help was also quite descriptive.

Digital signature with Microsof Word (on Windows)

Just for the record, I used Microsoft Office Word 2003.

Importing your certificate

You should import your certificate using Internet Explorer. Once this is done, the certificate should automatically appear in Word as one of your identities when you sign.

Signing the document

Use the "Tools" menu and click on "Options" at the bottom. A window opens with several tabs. Click on "Security". then on the panel click on the box labeled "Digital signatures". Another window opens to tell you who has signed the document already. If you want to add your signature you should click on the box labeled "Add...". The signature is not physically visible on the document. If you want to double check that the document has been signed you need to redo the process of opening the options menu. The online help was not quite descriptive (it does not tell you for instance that you need to use internet explorer to import your certificate, I found out by desparation).

-- DianaBosio - 24 Feb 2009

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Topic revision: r4 - 2009-02-24 - DianaBosio
 
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