PDF Security Guide: Passwords, Encryption & Permissions

Everything you need to know about protecting PDFs with passwords, encryption, and permission controls.

PDFs can carry sensitive information, so the format includes several layers of protection: passwords, encryption, permissions and digital signatures.

Passwords and encryption

An open password stops anyone without the password from viewing the file. A permissions password allows viewing but restricts actions like printing, copying or editing. Strong PDFs use AES-256 encryption.

Permissions

• Printing — allow, restrict to low resolution, or block
• Copying text and images
• Editing content or filling forms
• Adding comments and annotations

Digital signatures

A digital signature verifies who created a document and proves it has not been altered since signing — essential for contracts and legal paperwork.

Best practices

Use long, unique passwords, share them through a separate channel, and remove protection only on devices you trust. With PDFForge, unlocking and re-saving happens locally so your file is never exposed.