To encrypt a PDF or PDF Portfolio, you can use the Certificate Security Settings dialog box. You can also save your certificate settings, such as the documents to encrypt and trusted recipients, as a security scheme and reuse it to encrypt PDFs.

  1. Do any of the following to open the Certificate Security Settings dialog box:

    • Open a single PDF file or a component file in a PDF Portfolio, choose Security > Encryption > Encryption > Interactive Certificate. Or, open the Document Properties dialog box, click Security, and then select Certificate Security from the Security Method drop-down menu.

    • Open an entire PDF Portfolio, choose File > Document Properties…. In the Document Properties dialog box, on the Security tab, select Password Security from the Security Method menu.

  1. At the prompt, click Yes.

  2. In the Certificate Security Settings dialog box, decide whether to save the settings as a scheme. Click Next >.

  3. Select the document components to encrypt, choose a level of encryption from the Encryption Algorithm drop-down menu, and click Next>. The encryption algorithm and key length are version-specific. Choose a PDF version compatible with the recipients’ reader or PDF application.

    • If you select 128-bit, recipients must have PDF 1.5 and later to open the document.

    • If you select 128-bit AES, recipients must have PDF 1.6 and later to open the document.

    • If you select 256-bit AES, PDF version 1.7 and later are required to open the document.

  1. Create a list of recipients for the encrypted PDF and then click Next>. Remember to always include your own certificate in the recipient list so that you also have access to the document. Select trusted contacts from the left and then click Add>> to add them to the list of recipients. Then, you can change encryption settings as stated below:

    • To add more trusted identities, click Import Certificate to trust list and select a certificate file.

    • To check the information of a trusted recipient, select the recipient and then click Recipient Details to open the Certificate Attributes dialog box.

    • To remove a recipient, select one and then click Remove<<. Make sure your certificate is still on the recipient list unless you don’t want the access to the encrypted file.

    • To individually define permissions for each recipient, select one recipient and then click Set Permissions. In the Recipient Permission Settings dialog box, make any changes as needed and then click OK. For more information about recipient permissions settings, see Restrict PDF editing, printing, and copying.

  1. Click Finish. Then click Save Now to apply you changes to the document.


Create a list of recipients A. Import Certificate to trust list B. Create Certificate C. Set Permission D. Recipient Details

Apply certificate security with a specific scheme

Create a certificate-based security scheme that stores all your certificate settings and reuse it to help you work more efficiently. If the recipients are usually the same, save them in a scheme and directly apply the security scheme to the document without having to re-add recipients every time you manage security settings.

  1. Open a PDF document or a PDF Portfolio and do any of the following to open the Security Panel:

    • Choose Security > Encryption > Security Panel.

    • On the Sidebar Navigation pane, click Security Panel.

  1. Create a certificate-based security scheme if necessary. See Security Schemes.

  2. Do any of the following to apply certificate security with a security scheme:

    • Right-click on a security scheme you want to apply to the document and select Apply Security Scheme.

    • Click the scheme and choose Security Scheme Option> Apply Security Scheme.

    • Double-click the scheme.

  1. Click Yes to change the security settings of the document.

  2. Click Save Now to apply the new security settings.

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