Position-Dependent Cryptographic Key Generation for Chip Card Security

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Solution Overview

Problem

Existing cryptographic methods do not effectively integrate position-dependent parameters to ensure secure, location-specific cryptographic operations, particularly in chip card systems, where unauthorized access and distance verification are critical.

Innovation Solution

A method involving a chip card that determines and uses position data to generate a position-dependent cryptographic key through a distance-bounding protocol, ensuring that cryptographic operations are executed only when the chip card is within a specific location or area, using a key derivation function that combines user data and position information to create a secure, location-specific key.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cryptographic key is generated without position dependency, then the cryptographic operation can be performed anywhere, but security is compromised due to unauthorized access risk

Engineering Contradiction:
ImprovesecurityVSAvoidlocation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by making the cryptographic key dependent on the physical location of the chip card. The key derivation function incorporates position data (such as GPS coordinates or location identifiers) to generate location-specific keys. This ensures that the same chip card will have different cryptographic keys when used at different locations, thereby preventing unauthorized access while maintaining legitimate usage at authorized positions.

Inventive Principle:
Principle #3Local quality

2Reliability

If position data is integrated into key generation, then location-specific security is improved, but system complexity increases due to additional authentication steps

Engineering Contradiction:
Improvelocation-specific securityVSAvoidauthentication process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the position verification and key generation processes into a single integrated operation. The key derivation function simultaneously incorporates position data, user authentication credentials, and cryptographic parameters to generate the final key. This consolidation reduces the number of separate authentication steps while maintaining location-specific security, as the position verification is embedded within the key generation process rather than being a separate prerequisite step.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a distance-bounding protocol is implemented, then unauthorized access from remote locations is prevented, but the operation time increases due to additional verification steps

Engineering Contradiction:
Improveaccess controlVSAvoidoperation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by performing distance-bounding verification and position data validation before the actual cryptographic operation begins. The system first verifies that the chip card is within the authorized geographical area and obtains valid position data from the location service. Only after this preliminary verification succeeds does the system proceed to generate the cryptographic key and execute the protected operation. This sequencing ensures that time-consuming verification steps are completed efficiently upfront, preventing unnecessary delays in the main operational flow.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2949095B1Carrying out a position-dependent cryptographic operation with a position-dependent cryptographic key
Publication Date: 2018.10.03 BUNDESDRUCKEREI GMBH
  • EP2949095B1 patent drawingFigure 1
  • EP2949095B1 patent drawingFigure 2~3
  • EP2949095B1 patent drawing

AI summary

The invention relates to a method for carrying out a cryptographic operation, consisting of the following steps; first positional data (G; {G1, G2, G3, Gn}; P1; P2; P3) is determined or captured (202) by a chip card data value (120) is accessed (204); a key derivation function (138) is used (206) on the data value (120) and the first positional data for generating a first position-dependent cryptographic key (116; S1; S2; S3); the first position-dependent cryptographic key is used (208) for carrying out the cryptographic operation.