ISO/IEC 29167-21:2018

Overview

ISO/IEC 29167-21:2018 specifies a crypto suite based on the lightweight block cipher SIMON for air‑interface communications of RFID devices. It defines how SIMON is applied within the ISO/IEC 18000 family of air interface standards to provide common, interoperable security services for Tags (RFID transponders) and Interrogators (readers). The standard supports multiple SIMON block/key size variants and defines message formats, authentication methods, communication encapsulation, key management and conformance rules.

Key topics and technical requirements

• SIMON cipher variants: The suite supports several block/key size options (notably 64/96, 96/96, 64/128, 128/128 and 128/256 bits). Implementations must state which options they support.
• Authentication methods: Procedures for Tag authentication, Interrogator authentication and Mutual authentication are defined, including message/response formatting and state transitions.
• Communication protection: Methods to encapsulate commands and cryptographically protect Tag responses (integrity and confidentiality modes) are specified for air interface messages.
• Initialization and state machine: State diagrams, initialization/reset rules and a crypto suite state transition table govern secure session behavior.
• Key management: Key table structures and key update mechanisms for managing SIMON keys on Tags and Interrogators.
• Error handling and conformance: Normative rules for conformance, error reporting and protocol‑specific obligations for Tags and Interrogators.
• Supporting material: Annexes include a description of SIMON and SILC v3, test vectors, protocol‑specific information and normative tables for implementers.
• IP notice: The document draws attention to possible patent claims related to the technology (some patent contact information is provided).

Applications and practical value

• Provides a standardized, lightweight cryptographic option for securing RFID air interfaces used in:
  • Supply chain and inventory management
  • Asset tracking and logistics
  • Access control and secure identification
  • IoT devices where constrained resources require lightweight ciphers
• Enables interoperable security between different vendors’ Tags and Interrogators by specifying common message formats, authentication flows and key management.

Who should use this standard

• RFID device manufacturers and firmware developers implementing SIMON‑based security
• System integrators deploying secure RFID solutions for logistics, retail or access control
• Standards committees and application designers referencing a crypto suite for ISO/IEC 18000 air interfaces
• Security architects and compliance teams evaluating lightweight cryptographic options for constrained devices

Related standards

• ISO/IEC 18000 (air interface parameters for RFID)
• ISO/IEC 19762 (AIDC harmonized vocabulary)

Keywords: ISO/IEC 29167-21, SIMON crypto suite, RFID security, air interface, lightweight block cipher, RFID authentication, key management, ISO/IEC 18000.