Trajectory Anonymization Using Segmented Probe Data Chunks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing location-based services face challenges in maintaining user anonymity while providing accurate and timely navigation assistance, as trajectory data can be mined to reveal sensitive information about users' routines and locations.

Innovation Solution

A method and apparatus that enhance trajectory anonymization by segmenting and gapping data, introducing additional anonymizing factors such as re-segmenting, re-chunking, and randomized response delays to obscure the source of the trajectory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If trajectory data is collected and transmitted to location-based service providers, then service accuracy and utility are improved, but user anonymity and privacy are compromised

Engineering Contradiction:
Improveservice accuracyVSAvoidprivacy risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent divides continuous trajectory data into discrete chunks or segments, where each chunk contains a subset of location points. This segmentation allows the service provider to process and utilize the data for accurate location-based services while limiting the exposure of complete trajectory patterns that could reveal sensitive user information about routines and destinations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and removes identifying information from trajectory data before transmission to service providers. By taking out personally identifiable elements and retaining only the necessary location-based information, the system maintains service utility while eliminating the harmful privacy exposure that would occur with complete trajectory data.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-affected harmful factors

If trajectory data is anonymized by segmenting and gapping, then user privacy is protected, but service utility and accuracy may deteriorate

Engineering Contradiction:
Improveprivacy protectionVSAvoidservice utility
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent applies partial anonymization by selectively segmenting and gapping trajectory data rather than completely obscuring it. This partial action retains sufficient location information to maintain service utility and accuracy while introducing enough anonymization to protect user privacy, achieving a balance between the two competing requirements.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes parameters of the trajectory data such as time stamps, location precision, and data density during the anonymization process. By adjusting these parameters strategically, the system preserves the essential patterns needed for location-based services while modifying other parameters to enhance privacy protection.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If additional anonymizing factors are introduced to enhance privacy, then anonymity is improved, but data complexity and processing requirements increase

Engineering Contradiction:
Improveanonymity strengthVSAvoidprocessing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent performs anonymization processing in advance before transmitting trajectory data to service providers. By applying segmentation, gapping, and parameter changes beforehand, the system strengthens anonymity without requiring complex real-time processing at the service provider end, thus managing complexity effectively.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4099296B1Method, apparatus, and computer program product for anonymizing trajectories
Publication Date: 2025.12.31 HERE GLOBAL BV
  • EP4099296B1 patent drawingFigure 1
  • EP4099296B1 patent drawingFigure 2
  • EP4099296B1 patent drawingFigure 3

AI summary

Embodiments described herein relate to anonymizing of trajectories of mobile devices. Methods may include: receiving an input chunk of probe data points, where the input chunk includes probe data points spanning an input duration, where the input chunk represents at least a first input portion of a trajectory; generating, based at least in part on the input chunk, an output chunk of one or more probe data points, where the output chunk includes one or more probe data points spanning an output duration, where the output duration is different from the input duration, where the output chunk represents at least an output portion of the trajectory, where the first input portion of the trajectory and the output portion of the trajectory share at least a common portion of the trajectory; and providing the output chunk of one or more probe data points to a location-based service provider.