ATSC Recommended Practice: Digital Rights Management (DRM)

Document Information

• Document Number: A/362:2022-03
• Date: 31 March 2022
• Organization: Advanced Television Systems Committee (ATSC)
• Purpose: Provides best practices for implementers of A/360 and security/content protection provisions of A/344.

Introduction

• ATSC is a non-profit organization specializing in standards for broadcast television and multimedia data distribution.
• The recommended practice (RP) supersedes previous documents and includes material from A/344 and A/360.

Organization of Document

1. Scope: Overview of document
2. References: Documents and standards referenced
3. Definition of Terms: Acronyms and terminology
4. System Overview: DRM operation and relevant technologies
5. ROUTE/DASH Client Processing: DRM operation API and examples
6. Annexes: Example message flows and SLT signings

Key Sections

Scope

• Best practices for DRM as per ATSC standards.

References

• Informative references include IEEE, ISO/IEC, W3C, DASH-IF, and other ATSC standards.

Definition of Terms

• Compliance Notation: Defines optional and mandatory actions.
• Syntactic Elements: Describes reserved elements and symbolic references.
• Acronyms: Definitions for terms like DRM, CENC, MPEG, etc.
• Terms: Key definitions related to broadcast and DRM technology.

System Overview

• MPEG Common Encryption (CENC): Describes CENC's function to support multiple DRM systems.
  • Encryption Parameters: Use of KIDs and unique key identifiers.
  • License Acquisition: Stored in ISO BMFF segments.
• W3C Encrypted Media Extensions (EME): APIs for key exchange between web applications and DRM systems.
• A/344 Encrypted Media Extensions: Specific to Receiver Media Player.

ROUTE/DASH Client Processing

• Introduction: Supports CENC framework for DRM protection.
• Basic CENC Operation: Mechanisms for decrypting and playing DASH-formatted content.

MPD Support for Encryption

• Content Protection Descriptor: Identifies DRM schemes.
• Protection System Specific Header Box: pssh box for DRM.

Solution Framework for DRM

• Common encryption standards and signaling components.

Use of A/344 APIs

• Notifications for License Request: License request information.
• Provide a License: Process to retrieve valid licenses.
• Generate a License Request: When additional adaptation sets require separate licenses.

License Acquisitions Examples

• Broadcast Application, Connected: Example flow of license acquisition via Broadcast Application.
• Receiver Application, Connected and Unconnected: Example flows for connected and unconnected scenarios.

Signaling Examples

• Service Protected Signaling: SLT table indicating service protection status.

Conclusion

• The document provides comprehensive guidelines for implementing DRM in broadcast and multimedia.
• It emphasizes the importance of adhering to standardized methods for encryption and key exchange to ensure compatibility and security.