This document specifies how to extend the specification contained in ISO 32000-2 by adding extensions to the Encrypt dictionary to support the Advanced Encryption Standard (AES)-Galois/Counter Mode (GCM) encryption algorithm. These extensions are intended for developers of: ¾    software that creates PDF files (PDF writers); ¾     software that reads existing PDF files and (usually) interprets their contents for display (PDF readers); ¾     software that reads and displays PDF content and interacts with the computer users to possibly modify and save the PDF file (interactive PDF processors) and PDF products that read and/or write PDF files for a variety of other purposes (PDF processors). NOTE       PDF writers and PDF readers are more specialized classifications of interactive PDF processors and all are PDF processors. This document does not specify the following: —    specific processes for converting paper or electronic documents to the PDF file format; —    specific technical design, user interface implementation, or operational details of rendering; —    specific physical methods of storing these documents such as media and storage conditions; —    methods for validating the conformance of PDF files or PDF processors; —    required computer hardware and/or operating system.