Open the PDF you want to encrypt and select All tools > Protect a PDF > Encrypt with Certificate.
Last updated on
Aug 16, 2025
Learn how to use certificates to encrypt PDF documents in Adobe Acrobat, ensuring only intended recipients can view the contents.
Encrypting a PDF with a certificate protects its contents and confirms the sender’s identity using digital signatures. Only specified recipients can access the file, and you can assign different permission levels, such as allowing one group to fill and sign forms and another to edit pages. Certificates can be selected from trusted identities, files, an LDAP server, or the Windows certificate store. Always include your own certificate to retain access to the file.
Tip
If possible, encrypt documents using certificates from third-party digital IDs. If the certificate is lost or stolen, the issuing authority can replace it. If a self-signed digital ID is deleted, all PDFs that were encrypted using the certificate from that ID are inaccessible forever.
When prompted, select Yes to change the security.
In the Certificate Security Settings dialog box, select the document component to encrypt.
From the Encryption Algorithm dropdown menu, select the encryption level:
- 128-bit AES: Recipients need Acrobat or Acrobat Reader version 7 or later
- 256-bit AES: Recipients need Acrobat or Acrobat Reader version 9 or later
Select Next.
Create a recipient list for the encrypted PDF:
- Select Search to locate identities in a directory server or your list of trusted identities.
- Select Browse to locate the file that contains certificates of trusted identities.
To set printing and editing restrictions for recipients, select them from the list and select Permissions.
Select OK and then select Next to review your settings.
Select Finish to apply the encryption.
When recipients open the PDF, the security settings you specified for each person will be applied.
