On-Body Acoustic Key Transfer via Omnidirectional Sensor Array

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Solution Overview

Problem

Existing on-body communication systems face challenges in securely transferring secret keys due to reliance on third-party manufacturers, human error, and inefficiencies in commissioning processes, particularly with direction-sensitive acoustic conduction methods.

Innovation Solution

A secure on-body communication system utilizing a peripheral unit with an acoustic signal generator and a body-mountable unit equipped with a two-dimensional array of acoustic sensor elements for reliable reception of data-encoded acoustic signals, eliminating the need for traditional commissioning processes and enhancing flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pre-programming secret keys during manufacture is used, then key distribution is simplified, but security is compromised due to third-party manufacturer access

Engineering Contradiction:
Improvekey distribution processVSAvoidsecurity of key values
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The system performs preliminary actions by establishing secure communication channels and exchanging cryptographic keys before the actual data transmission begins. The commissioning process includes authentication handshakes and key establishment protocols that prepare the system for secure operation in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary cryptographic key exchange mechanism that mediates between the body-mountable unit and the further unit. Instead of direct key sharing, a secure key exchange protocol acts as an intermediary to establish shared secrets without exposing them to potential attackers or third parties.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If secret keys are transferred during commissioning via OOB channel, then security is improved, but commissioning complexity and time increase

Engineering Contradiction:
Improvesecurity of key transferVSAvoidcommissioning process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the commissioning process with the initial device pairing process. The secure key exchange is integrated into the same interaction sequence where devices establish their communication link, eliminating the need for separate commissioning steps and reducing overall complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system performs preliminary authentication and key exchange actions during the initial device pairing phase. By establishing secure credentials before full operational mode is activated, the system avoids requiring separate commissioning procedures later.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If direction-sensitive acoustic conduction is used, then secure key transfer is achieved, but reception reliability decreases due to orientation requirements

Engineering Contradiction:
Improvesecurity of communicationVSAvoidreception reliability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent employs asymmetric acoustic sensor element arrangements on the body-mountable unit. The sensor elements are positioned and oriented in specific asymmetric patterns that enable the device to receive acoustic signals from multiple directions, eliminating the need for precise orientation alignment between transmitting and receiving devices.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The system transitions from one-dimensional directional acoustic reception to two-dimensional or three-dimensional omnidirectional reception by arranging acoustic sensor elements in spatial patterns. This dimensional expansion allows signal reception from any direction in the acoustic field.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system ensures secure and efficient key transfer with improved reliability and flexibility, reducing the risk of human error and third-party interference, while avoiding the limitations of direction-sensitive acoustic reception.

Implementation Method 1

a body-mountable unit (20) having an acoustic signal receiver (22) for receiving body-coupled acoustic signals from the body of the subject

Methodology Applied
Scientific EffectAcoustic conduction: Sound

Implementation Method 2

the signal receiver comprising an array of acoustic sensor elements (30) having sensing parts exposed at a body-contact surface of the body mountable-unit

Methodology Applied
Scientific EffectAcoustic signal detection: Sound

Data Source

PatentEP3868040B1On-body communication system and method of commissioning the same
Publication Date: 2024.12.11 KONINKLIJKE PHILIPS NV
  • EP3868040B1 patent drawingFigure 1~3
  • EP3868040B1 patent drawingFigure 4~5
  • EP3868040B1 patent drawingFigure 6~7

AI summary

An on/in-body communication system (10) is described that may include a peripheral, (such as, for example portable, unit (12)) and body-mountable unit (20). The peripheral unit and body-mountable unit may communicate via body-coupled acoustic signals. This may facilitate secure transmission of a secure key from the peripheral unit to the body- mountable unit. The body-mountable unit may include an array (28) of acoustic sensor elements (30) disposed at a body-coupling surface (32) of the body-mountable unit for receiving a transmitted acoustic signals, the array formation facilitating multi- or omni- directional sensing. A key may be transferred in an initialization procedure which may include establishing communications with an external device (42) via an off-body communication medium, acquiring from the external device a secure key, and/or driving acoustic transmission of the secure key to the body-mountable device via an acoustic signal generator (14).