UWB Communication Node for Secure Contention-Based Ranging

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Solution Overview

Problem

Existing ultra-wideband (UWB) communication systems face security risks due to the use of a single shared cryptographic session key, which allows responder nodes to impersonate each other and are vulnerable to interference by third parties, especially in contention-based ranging protocols.

Innovation Solution

Implementing a UWB communication node with a common cryptographic session key for message encryption and responder-specific session keys for response decryption, derived from a random number and MAC addresses, to enhance security and reduce impersonation risks while maintaining computational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single shared cryptographic session key is used for all responder nodes, then device complexity is reduced and ease of operation is improved, but security is worsened due to impersonation vulnerabilities and third-party interference

Engineering Contradiction:
Improveease of operationVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent segments the cryptographic session keys into two distinct types: a common session key shared by all responder nodes for basic communication, and individual responder-specific session keys for secure identification. This segmentation allows the system to maintain operational simplicity through the common key while enhancing security through the unique keys, directly resolving the contradiction between ease of operation and security.

Inventive Principle:
Principle #1Segmentation

2Reliability

If responder-specific cryptographic session keys are implemented for each responder node, then security is improved by reducing impersonation risks, but device complexity increases due to key management requirements

Engineering Contradiction:
ImprovesecurityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functionality of multiple key types into a unified cryptographic framework where both common and responder-specific session keys operate within the same protocol structure. The common session key handles general communication encryption, while responder-specific keys handle identification, allowing the system to achieve enhanced security without proportionally increasing complexity through integration rather than separate management systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common cryptographic session key serves multiple functions: it encrypts communication between the controller and all responder nodes, provides a baseline security layer, and works in conjunction with responder-specific keys. This multi-functionality reduces the need for entirely separate key management systems, thereby limiting the increase in device complexity while maintaining improved security through the use of responder-specific keys.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If a common cryptographic session key is used for message encryption, then computational efficiency is improved, but security is worsened due to vulnerability to interference by third parties

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidsecurity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments cryptographic operations into two layers: a common session key layer for efficient bulk message encryption across all responder nodes, and a responder-specific key layer for secure identification and authentication. This segmentation allows the system to maintain high computational efficiency through the common key while adding targeted security measures only where needed for identification, minimizing the impact on overall computational performance.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4044636B1An ultra-wideband communication node and method for contention based ranging
Publication Date: 2025.10.08 NXP BV
  • EP4044636B1 patent drawingFigure 1~2
  • EP4044636B1 patent drawingFigure 3
  • EP4044636B1 patent drawingFigure 4

AI summary

Disclosed is a UWB communication node comprising: a UWB communication unit configured to transmit one or more messages, to a plurality of external responder nodes and comprising a ranging control message defining a contention period, and further configured to receive one or more responses from said responder nodes during said contention period, each response including a response payload; a processor unit configured to use a common cryptographic session key to encrypt said messages; wherein the processing unit is further configured to use responder-specific session keys to decrypt the response payloads; wherein each individual one of said responder-specific cryptographic session keys is a unique key shared between the node and one of the external responder nodes. Corresponding systems methods and an associated computer program are also disclosed.