Overview - ISO/TS 21219-24:2017 (TPEG2-LTE)
ISO/TS 21219-24:2017 specifies Light Encryption (TPEG2-LTE) for Traffic and Travel Information (TTI) delivered using the TPEG2 framework. The technical specification defines a conditional access and encryption mechanism for TPEG Service Data Frames aimed at Business-to-Business (B2B) delivery models. It provides a simple, standardized method for protecting TPEG payloads for both broadcast and point-to-point distribution, reducing the need for proprietary solutions and lowering implementation effort for service providers and device manufacturers.
Key topics and technical requirements
- Scope and purpose: Defines the LTE encryption mechanism for TPEG service payloads and control data to support conditional access.
- Operational constraints: Version number signalling, extendibility, and endianness considerations to ensure interoperability.
- Performance requirements: Repetition and update rates for encryption parameters to maintain real‑time delivery performance.
- Security and licensing: Requirements for license agreements and security practices for service providers and client device manufacturers.
- Encryption architecture:
- Principles of operation and an overview of the light encryption method.
- Use of a TISA secret KeyTable and parameters protected in confidence.
- Encryption/decryption of service data frame payloads and Control Words.
- Use of a block cipher mode of operation and composition of the Initialization Vector (IV).
- Definition of Service Key composition and support for Light Encryption Mode 1 and Mode 2.
- Message embedding and data structures:
- How LTE components and tables are embedded in TPEG service data frames.
- Defined datatypes (e.g., ControlWord, Nonce) and LTE tables for consistent implementation.
- Annexes and guidance: Normative binary and XML representations and informative implementation guidelines.
Applications - who uses this standard
- TPEG service providers and broadcasters: to secure B2B content distribution and manage conditional access.
- Device manufacturers and OEMs: to implement interoperable decryption for receivers, in-vehicle systems, and navigation devices.
- ITS integrators and software developers: to standardize encryption handling in traffic information platforms and middleware.
- Content aggregators and transport authorities: to deliver protected traffic, travel and location-related services over broadcast or IP links.
Related standards
- Part of the TPEG2 family: ISO/TS 21219 series (including toolkit parts like -1, -2, -3, -4, -6, -7 and application parts such as -14, -15, -16, -18, -19, -23, -25). These define TPEG2 modelling, framing, and application rules that TPEG2-LTE complements.
Keywords: ISO/TS 21219-24:2017, TPEG2-LTE, TPEG, light encryption, traffic and travel information, conditional access, B2B, service data frames, broadcast, point-to-point.
Open preview (PDF)Intelligent transport systems — Traffic and travel information (TTI) via transport protocol experts group, generation 2 (TPEG2) — Part 24: Light encryption (TPEG2-LTE)
