The Office Document Cryptography Structure is relevant to documents that have Information Rights Management (IRM) policies, document encryption, or signing and write protection applied. More specifically, this file format describes the following:
A structure that acts as a generic mechanism for storing data that has been transformed along with information about that data.
A structure for storing rights management policies that have been applied to a particular document.
Encryption, signing, and write protection structures.
Sections 1.7 and 2 of this specification are normative. All other sections and examples in this specification are informative.