PDF security settings control two distinct aspects: document access and document permissions.
Encryption strength options include 128-bit AES and 256-bit AES. The 256-bit option is recommended for sensitive documents.
Permission controls allow granular restriction of printing, content copying, form filling, annotation, page extraction, and document assembly.
Certificate-based encryption allows specifying individual recipients who can open the document using their digital certificates.
Batch encryption processes multiple files with the same security settings.