ISO/IEC 29192-7:2019

Overview

ISO/IEC 29192-7:2019 - "Information security - Lightweight cryptography - Part 7: Broadcast authentication protocols" defines lightweight broadcast authentication protocols for constrained environments. The standard focuses on providing data integrity and entity authentication in one-to-many (broadcast) settings where digital signatures may be too costly. It specifies protocol structure, system parameters and a concrete lightweight option (TESLA‑RD), while leaving the establishment of the key‑binding infrastructure (linking a sender to a cryptographic secret) out of scope.

Key topics and requirements

• TESLA‑RD (Timed Efficient Stream Loss‑tolerant Authentication - Rapid Disclosure): the primary protocol described for lightweight broadcast authentication.
• Cryptographic primitives:
  • MAC algorithms from ISO/IEC 9797 or ISO/IEC 29192‑6.
  • Collision‑resistant hash functions from ISO/IEC 10118 or ISO/IEC 29192‑5.
• Chain of keys: keys are generated by repeatedly applying a collision‑resistant hash to a random seed key (K_N) and optional value α to resist time‑memory trade‑off attacks.
• Time‑based operation:
  • Time is split into fixed intervals (parameter D).
  • A disclosure delay (d) defines how long after sending a MAC the key used to compute it is revealed.
  • The receiver’s and sender’s clocks must be synchronized within a known bound (ε).
• Operational phases: Initialization, Setup (key chain generation and distribution), Sending messages (MAC + interval index + disclosed key), Receiving/storing packets, Verifying keys via hash chains, and Verifying message MACs.
• System parameters: D, d, N (chain length), α length and representation details are public and decided before deployment.
• Object identifiers: Annex A assigns OIDs for algorithms used in the document.

Practical applications

• Broadcast scenarios where low overhead is critical:
  • Satellite telemetry and satellite broadcast services
  • Wireless sensor networks and IoT/mass‑deployed devices
  • Firmware/firmware update distribution over broadcast links
  • Digital radio, telemetry streams, and other multicast systems
• Environments with constrained CPU, memory and communication budgets where digital signatures are impractical.

Who should use this standard

• Security architects and systems engineers designing broadcast or multicast authentication for constrained devices.
• Embedded and IoT developers implementing lightweight cryptographic protocols.
• Satellite communications and telemetry engineers seeking low‑cost authentication mechanisms.
• Standards compliance teams and evaluators verifying conformance with lightweight broadcast authentication practice.

Related standards

• ISO/IEC 29192 series (Lightweight cryptography - general, hash‑functions, MACs)
• ISO/IEC 9797 (Message authentication codes)
• ISO/IEC 10118 (Hash‑functions)

Keywords: ISO/IEC 29192-7:2019, lightweight cryptography, broadcast authentication, TESLA‑RD, MAC, hash function, chain of keys, IoT security, satellite telemetry.