In Acrobat or Acrobat Reader, go to Edit > Preferences (Windows), or Acrobat > Preferences (macOS).
Adobe Approved Trust List update dialog appears in Acrobat or Acrobat Reader
When you use Acrobat or Acrobat Reader to open PDF documents that were signed or certified using certificates, you see the message "A new security settings update is available from Adobe Systems. Would you like to install it now?"
The dialog refers to updates to the root certificate list (AATL) in Acrobat or Acrobat Reader.
- To install the security settings and update the root certificates list, click Yes.
- To manually update the root certificates list at a later time, click No.
Adobe Approved Trust List (AATL)
Adobe Approved Trust List (AATL) is a program that allows millions of users around the world to create digital signatures. The signatures are trusted whenever the signed document is opened in Acrobat or Acrobat Reader. The list of trusted certificates is updated from time to time in case some certificates have been added, renewed, or have expired. To know more, see Adobe Approved Trust List (AATL).
These updates are distinguished from the standard product updates for Acrobat or Acrobat Reader, which can be triggered by choosing Help > Check For Updates.
Manually Update the Adobe Approved Trust List (AATL) in Acrobat or Acrobat Reader
From the categories on the left, choose Trust Manager.
To manually update the trust settings, click Update Now in the Automatic Adobe Approved Trust List (AATL) updates section.Note:
To automatically check and download the trust settings from an Adobe server, select the option Load Trusted Certificates From An Adobe AATL Server. This setting ensures that the user or organization associated with the certificate has met the assurance levels of the Adobe Approved Trust List program. The certificate updates are triggered under the following conditions:
- When you open a PDF that has a digital signature.
- You have never checked for updates before.
- You have checked for updates before but 28 days have elapsed, or a new update is available.
In the Trusted Certificates Update dialog box, click OK.
Click OK in the security settings updated confirmation dialog.
The Adobe Approved Trust List (AATL) is now updated.
Manage the Adobe Approved Trust List update in an enterprise environment
To control the trusted root certificates update mechanism for an enterprise deployment, use the Acrobat Customization Wizard. For more information, see Configuring online features using the Acrobat Customization Wizard.