Secure Distance Bounding via Angle of Departure Measurement

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Solution Overview

Problem

Conventional methods for secure distance estimation in wireless systems, such as RSS and RTT-based methods, are vulnerable to attacks from remotely located high-power transmitters or directive antennas, which can manipulate signal strength and propagation delays.

Innovation Solution

The method involves determining a first and second angle of departure or arrival using spatially separate antennas, with the difference between these angles used to generate secure distance estimation data, providing a more robust proximity verification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If RSS-based proximity detection is used, then distance estimation can be obtained, but the system becomes vulnerable to attacks by remotely located high-power transmitters that manipulate signal strength

Engineering Contradiction:
Improvedistance estimation accuracyVSAvoidsecurity against signal manipulation attacks
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the measurement parameter from signal strength (RSS) to angle of departure (AoD). By measuring the angle at which the signal departs from the transmitter antenna array rather than the strength of the received signal, the system achieves distance estimation that cannot be manipulated by high-power transmitters, as the angular information remains authentic even if signal strength is altered by attackers

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces angle of departure measurement as an intermediary parameter between the transmitter and receiver. Instead of directly relying on signal strength which can be manipulated, the system uses AoD as a mediating measurement that provides indirect but secure information about distance, creating a trust layer that prevents attack exploitation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If RTT-based proximity detection is used, then distance estimation can be obtained, but the system becomes vulnerable to attacks by remotely located transmitters using predictive algorithms that manipulate response timing

Engineering Contradiction:
Improvedistance estimation accuracyVSAvoidsecurity against timing manipulation attacks
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the measurement parameter from time-based (RTT) to angle-based (AoD). By measuring the angle of departure of the signal rather than the round-trip time, the system eliminates vulnerability to predictive algorithm attacks, as angular measurement cannot be manipulated by timing-based exploitation even with advanced processing

Inventive Principle:
Principle #35Parameter changes

3Reliability

If spatially separate antennas are used for angle measurement, then security against signal manipulation is improved, but device complexity increases

Engineering Contradiction:
Improvesecurity against signal manipulation attacksVSAvoidantenna array complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the antenna system into multiple spatially separate antennas or antenna elements. By dividing the single antenna into multiple segments arranged in a specific geometry, the system can measure angle of departure through phase or amplitude differences between elements, achieving secure measurement while using standard antenna array technology

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the antenna array serve multiple functions: it acts as both the transmitting antenna and the angle measurement sensor. The same physical antenna structure used for signal transmission also provides the spatial information needed for AoD measurement, eliminating the need for separate sensing components and reducing overall system complexity

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

Data Source

PatentEP2789181B1Method, apparatus, and computer program product for secure distance bounding based on direction measurement
Publication Date: 2020.04.01 NOKIA TECHNOLOGIES OY
  • EP2789181B1 patent drawingFigure 1A
  • EP2789181B1 patent drawingFigure 1B
  • EP2789181B1 patent drawingFigure 1C

AI summary

Method, apparatus, and computer program product example embodiments provide secure distance estimation based on direction measurement. According to an example embodiment of the invention, a method comprises receiving, by an apparatus (102) from a remote device (100), one or more wireless packets including information packets containing angle of departure information (160) of the remote device (100); determining in the apparatus (102), a first angle of departure and a second angle of departure from the received angle of departure information; and generating distance estimation data in the apparatus relative to the remote device (100), based on the determined first angle of departure and second angle of departure.