PDF Cryptography Overview: AES & RC4 Secure Algorithms

Securing PDF documents involves encrypting the file's object stream. PDF specifications support multiple levels of security to restrict document access and control permissions (such as disallowing printing, editing, or copying text).

PDF security distinguishes between two passwords. The User Password (or Open Password) is required to decrypt and view the document. The Owner Password (or Permission Password) is required to modify document permissions or unlock security restrictions.

Modern PDF tools utilize 128-bit or 256-bit Advanced Encryption Standard (AES) algorithms. AES provides strong cryptographic protection. Because LovethePDF runs entirely locally inside your browser, all password generation and encryption occur in sandboxed memory, ensuring no passwords are sent to servers.