Transponder Privacy Protection via Encrypted ID Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing transponder systems compromise privacy and traceability by using fixed identification numbers, making it possible to associate and track individuals, which is undesirable for card owners.

Innovation Solution

A transponder system that expands a fixed identification number with a random number and encrypts the combined data with a shared key, allowing the transponder to send an encrypted number to a reader, which can then decrypt and extract the fixed identification number, maintaining privacy and preventing traceability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed identification number is used to identify a transponder, then the transponder can be unambiguously identified and reliably communicated with, but the privacy and traceability of the owner is compromised

Engineering Contradiction:

Improveidentification reliabilityVSAvoidprivacy loss

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The identification system is segmented into two distinct parts: a fixed identification number stored in the transponder for reliable identification, and a random number generated during each session for privacy protection. This segmentation allows the fixed ID to remain secure while the random component prevents tracking, resolving the contradiction between identification reliability and privacy preservation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A random number acts as an intermediary between the fixed identification number and the communication process. Instead of transmitting the fixed ID directly, the system uses the random number as a mediator that obscures the fixed ID during transmission, thereby maintaining both reliable identification (through the fixed ID) and privacy (through the random intermediary).

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a random identification number is used to protect privacy, then the owner's traceability is prevented, but the transponder cannot be reliably identified across different sessions

Engineering Contradiction:

Improvetraceability preventionVSAvoididentification consistency

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixed identification number is preliminarily stored in the transponder during manufacturing, establishing a reliable baseline for identification. During each session, a random number is then generated as a temporary overlay that protects privacy while allowing the pre-stored fixed ID to ensure consistent identification across sessions.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If encryption is applied to the fixed identification number with a random number, then privacy is maintained and tracking is avoided, but the system complexity increases

Engineering Contradiction:

Improveprivacy protectionVSAvoidsystem complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system changes the parameter of the identification number by combining a fixed ID with a randomly generated number during each session. This parameter change (from static to dynamic composition) enables privacy protection through encryption while maintaining manageable system complexity, as the underlying fixed ID structure remains simple and well-defined.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2297667B1System of providing a fixed identification of a transponder while keeping privacy and avoiding tracking

Publication Date: 2018.03.28 NXP BV

Figure 1
Figure 2
Figure 3

AI summary

Transponder (180) having stored a fixed identification number, which expands said identification number with a random number, encrypts said expanded number with a key, and sends it to a reader (160) on its request. Reader (160), which on request receives an encrypted number from a transponder (180), decrypts a received encrypted number with a key, which was also used by the transponder (180), and extracts a fixed identification number associated with the transponder (180).