Signatures are validated when a document is opened, and then automatically re-validated when anyone changes the document. To view the status of your certificates and signatures, do one the following:. View certificates and signatures in the Signatures pane.

Methods to secure a PDF file with certificate security

Look at certificates and signatures on the page of the PDF document.

• The Signatures pane. The Signatures pane lists all signatures in the PDF document, shows their validity status, and provides a summary of each signature.
• If your PDF document contains signatures, the Signatures tab appears on the left of the window. To open the Signatures pane, click the Signatures tab. TIP: To jump to the location of a signature in the document, click on the signature in the Signature pane.
• A yellow rectangle highlights the selected signature. View signatures and certificates on the page of a PDF document.
• To see more information about a digital signature or certificate from the page of a PDF document, click on the signature.
• The Signature Properties dialog appears, and lets you do the following:. Validate signature: confirm the validity of a digital signature.

To apply certificate security with a specific profile:

1. Document modification: see whether the document is unchanged, or if the file is restricted to permitted changes, such as filling-in form fields.
2. Time validity: shows that the timestamp of the PDF document is one of the following: 1.

To manage certificate security:

Based on the clock from the signer’s computer.

1. Has a timestamp that cannot be verified.
2. Timestamped and verified from a timestamp server.
3. View certificate: shows you information about the person who signed the document, the expiration date of the certificate, and who issued the certificate.
4. You can also see the encryption standard and digital encryption fingerprints.
5. Add to Trusted Contacts: add the person who signed this PDF file to your list of contacts. For more information, see Manage trusted contacts.
6. Digital IDs let you encrypt files that can only be opened and used by people who have exchanged certificates.

Certificate-based security has many advantages over password-based security: documents can be opened without the need to remember passwords, Digital IDs cannot be shared or copied easily, the one document can contain different security settings for each recipient of a file.

1. For example, you may grant one person editing and printing privileges, while another is limited to just viewing the file.
2. Before you can receive files encrypted for your digital ID, you must create your digital ID and then share its certificate with people who you intend to share certificate-secured files.
3. You must have also received and imported the certificate of the recipient before you can encrypt files for their use.
4. Note: When you use certificate-based security, remember to add your own certificate as an intended recipient.
5. Otherwise, you will not have access to the PDF file when it is secured.

There are two ways to secure a PDF file with certificate security.