USB Device Class Specification

1 Introduction
The need for the protected and controlled distribution of digital content is the basis of the USB Content Security Interface (CSI) described in this specification.
1.1 Purpose
The purpose of the USB Security Class is to specify a common set of USB data transport requests and descriptors necessary to support the various Content Security Methods (CSM). CSMs may use some or all of the services detailed in this specification. A CSM defines the USB support given to a particular Content Protection Method (CPM). The intent is that each CSM will be detailed in a separate but associated USB CSM specification.
1.2 Scope
This specification details the USB CS functionality, requests, and descriptors that support the various CSMs. CSMs
are listed in Appendix A along with the corresponding CSM identification number assignment. Each CSM is
detailed in a separate but associated Content Security Method Specification that contains data detailing its USB
implementation. CSMs are added to the CS list by vote of USB CSWG and are subject to the USB specification
promotion process. The basic services needed to support these various CSMs are shown in the following bulleted list.
• Activating/Deactivating a particular CSM.
• Associating/Disassociating a CSM to a data transport channel (Isochronous, Bulk, Control).
• A notification service that allows either the Host or Device or both to initiate asynchronous CSM related communication.
• Uniquely identify each CSM for Host driver support.
1.3 Related Documents
• Universal Serial Bus Specification, Version 1.1 (also referred to as the USB Specification). In particular, see Section 9, “USB Device Framework.”
• Universal Serial Bus Common Class Specification, Revision 1.0.