You must register a digital ID in Acrobat before you can use it.
- Choose Advanced > Security Settings.
- Select Digital IDs, and click Add ID.
- Select Browse For An Existing Digital ID File.
- Follow the on-screen instructions to select the digital
ID file, type your password, and register the digital ID.
You can create self-signed
digital IDs in Acrobat.
Or, see the Adobe website for information on acquiring a digital
ID from Adobe security partners.