In the context of cryptography, encryption serves as a mechanism to ensure confidentiality. Since data may be sensitive information such as passwords and personal communication may be exposed to potential interceptors. To protect this information encryption allows the lock and protection of documents. PTSource PDF Knitter Plus allows you to protect and organize your PDF files. You can merge, split, reorder, watermark, encrypt with AES 128 bit, extract images, prevent printing, prevent modifying, password protect and more.