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Security Settings

Detailinformation

If this is the first time you are signing a document electronically or verifying an electronic signature, you will need to check the security settings for your Acrobat Reader DC first.

Launch Acrobat Reader DC without opening a document.

Open Preferences by clicking Menu, and then clicking Preferences.

Screenshot of the Adobe Acrobat home page. The menu is open. Preferences is located between Help and Protection. It can also be opened by pressing Ctrl+K.

Trusted Services

Please note
Make sure that you configured a root certificate that you fully trust.

Deselect automatic updates of the certificate list

Under "Categories", select Trust Manager.

Uncheck the box under "Automatic Adobe Approved Trustlist (AATL) updates" and "Automatic European Union Trust Lists (EUTL) updates".

Screenshot of the Preferences. Below Categories is a list of settings. Trust Manager is located between Tracker and Units. The two checkboxes are the third and fourth items in the Trust Manager.

Delete pre-installed root certificates

To delete the root certificates preinstalled by Adobe, click Signatures under "Categories".

Under "Identities & Trusted Certificates", click More.

Screenshot of the Preferences. Signatures is located in the Categories, between Security (Enhanced) and Spelling. Identities & Trusted Certificates is the third item on the Digital Signatures Page

Click Trusted Certificates.

The Adobe Trustlist (AATL) and the European Union Trust Lists (EUTL) provide a long list of trusted certificates.

Select all certificates and click Delete.

Screenshot of the Trusted Certificates page with a long list of certificate in the table. "Delete" is the last button in the tool bar, after Certificate Details.

Adobe Root CA G2-Certificate cannot be deleted

Please note that the Adobe Root CA G2-Certificate (and sometimes also the Adobe Root CA) cannot be deleted or can be deleted but will appear automatically the next time you open Adobe Acrobat.

Close the Trusted Certificates Settings.

Screenshot of the Trusted Certificates page with all certificates deleted except for Adobe Root CA G2.

Configure Timestamp

The DFN provides a verifiable and trusted timestamp that can be attached to the electronic signature. The timestamp is independent of the individual time configuration of your device. Since this time configuration can be manipulated, RWTH Aachen uses the DFN timestamp server.

Open the Timestamp Settings

Click Signatures.

Under "Document Timestamping" click More.

Screenshot of the Preferences. Document Timestamping is the fourth and last element on the page Digital Signatures.

Time server Settings

The dialogue box "Server Settings" opens.

Click the button New (+) in the Top-Navigation

Screenshot of the Server Settings. The button New is the first element in the Top-Navigation, next to Edit.

Configure the time server

The dialogue box "New Time stamp Server". Enter the following configuration settings:

Name = DFN-Timestamp
Server-URL = http://zeitstempel.dfn.de

Click OK to close the dialogue box.

Screenshot of the New Time Stamp Server dialogue box. The settings are listed above.

Set the DFN Timestamp as the default

Select the DFN Timestamp in the table and click on Set Default.

Screenshot of the Server Settings. Set Default is the last item in the navigation, after Remove.

Click OK to confirm your choice.

Screenshot of the Adobe Security pop-up window. The text begins with "Are you sure you want to make this server your new default server?". OK is located under the text.

Additional Information

For more information on the DFN Timestamp service, visit the DFN website.

last changed on 04/04/2025

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