Credential Container Secret Data Update Method

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Solution Overview

Problem

There is a need to securely update the secret data used for authentication in tamper-resistant elements, such as SIM cards, within telecom communication networks, as existing methods lack efficient and secure mechanisms for replacing authentication keys.

Innovation Solution

A method involving a credential container that receives and deciphers new secret data from a remote server using a subset of secret parameters and a different encryption algorithm, replacing the existing secret data, with options including the Milenage or TUAK algorithms and one-time-pad encryption, ensuring secure authentication key updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If secret data is updated using the same symmetric mutual authentication algorithm, then consistency is maintained, but security is compromised if the algorithm or channel is compromised

Engineering Contradiction:

Improveauthentication securityVSAvoidalgorithm flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies asymmetry by using different algorithms for authentication (symmetric mutual authentication) versus for updating secret data (different second algorithm). This ensures that compromise of one algorithm does not affect the other, enhancing security while maintaining operational versatility.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent segments the algorithm usage into distinct purposes: symmetric mutual authentication algorithm for authentication, and a different second algorithm for updating secret data. This segmentation isolates security risks to specific algorithmic functions.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If secret data is transmitted through provisioning channels, then initial setup is complete, but security is vulnerable if provisioning channels are compromised

Engineering Contradiction:

Improveprovisioning capabilityVSAvoidsecret data security

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism where secret data is enciphered using a one-time-pad derived from current secret data and secret parameters before transmission. This intermediary encryption layer protects the provisioning channel from compromise.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the state of secret data by enciphering it using dynamic parameters (current secret data and secret parameters) to create a one-time-pad. This parameter-based transformation ensures that even if provisioning channels are compromised, the secret data remains secure.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the same algorithm is used for both authentication and secret data update, then system complexity is reduced, but security is weakened

Engineering Contradiction:

Improvealgorithm managementVSAvoidsecret data protection

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments algorithm usage into distinct functional areas: symmetric mutual authentication algorithm for authentication operations, and a different second algorithm for secret data updates. This segmentation prevents a single point of failure while maintaining manageable system complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent deliberately introduces asymmetry by using different algorithms for different purposes. This asymmetric approach enhances security by ensuring that compromise of one algorithm does not compromise the other, while the system manages this complexity through clear algorithm assignment.

Inventive Principle:

Principle #4Asymmetry

4Productivity

If secret data is updated without encipherment, then update speed is increased, but security is compromised

Engineering Contradiction:

Improveupdate speedVSAvoidauthentication key security

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent transforms secret data into enciphered form using parameter-based one-time-pad encryption before transmission and storage. This parameter-based transformation maintains security while enabling efficient update mechanisms through the use of derived encryption keys.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses current secret data itself as part of the encipherment mechanism (in the one-time-pad generation). This self-service approach allows the credential container to securely update its own secret data without external encryption keys, maintaining both security and update efficiency.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12074972B2Method for updating a secret data in a credential container

Publication Date: 2024.08.27 THALES DIS FRANCE SA

AI summary

The invention is a method for updating a first secret data in a credential container including a subscriber identity module. The credential container comprises a set of secret parameters customized for a network operator and is configured to execute a symmetric mutual authentication algorithm using said set. The credential container receives from a remote server a second secret data enciphered using a second algorithm different from said symmetric mutual authentication algorithm and a subset of said secret parameters, the credential container deciphers the enciphered second secret data by using both the subset and a third algorithm and replaces the first secret data with the second secret data.