To add a password and encrypt a PDF file with specific settings and permissions using Indigo PDF, follow these steps:

1. Select PDF to Encrypt:

• Use the application’s file selection or upload feature to choose the PDF file that you want to encrypt.

1. Add Owner Password:

• Set an owner password if you want to restrict what can be done with the document once it’s opened. The owner password provides control over various permissions. Enter the desired owner password in the provided field.

1. Add User Password:

• If you also want to restrict access to the document itself (i.e., opening the PDF), set a user password. Enter the user password in the provided field.

1. Encryption Key Length:

• Select the encryption key length. Higher values provide stronger encryption but may have compatibility issues with older PDF readers, while lower values offer better compatibility. Choose an appropriate key length based on your security and compatibility requirements.

1. Set Permissions:

• Choose the specific permissions you want to set. These permissions define what actions can be performed on the PDF. Common permissions include:
• Prevent assembly of the document
• Prevent content extraction
• Prevent extraction for accessibility
• Prevent filling in forms
• Prevent modification
• Prevent annotation modification
• Prevent printing
• Prevent printing in different formats

1. Encrypt PDF:

• After configuring the owner password, user password, encryption key length, and permissions, click the “Encrypt” or “Start” button to apply the encryption.

1. Download the Encrypted PDF:

• Once the encryption process is complete, you will be prompted to download the encrypted PDF file. Select a destination folder on your computer and provide a name for the encrypted PDF file if needed.

1. Confirmation:

• You will receive confirmation that the PDF has been successfully encrypted with the specified settings and permissions.

By following these steps, you can add a password and encrypt a PDF using Indigo PDF with owner and user passwords, select encryption key length, and define specific permissions to control how the document can be used by others. This enhances the security of your PDF document and protects it from unauthorized access and actions.