End-to-End Encryption Key Management via Validity Indications

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In end-to-end encrypted communication systems, dynamic key management becomes complex and unpredictable when network operators and communicating parties lack simultaneous access to key changes, particularly in group communications where all members must use the same encryption key, leading to potential disruptions or safety risks.

Innovation Solution

Associating end-to-end encryption keys with a validity indication that specifies a cryptographic group and a valid period, allowing for easier and more predictable key management, ensuring all members of a group can use the same key within that period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If end-to-end encryption keys are changed dynamically to avoid interception, then security is improved, but key management complexity increases and operations become unpredictable

Engineering Contradiction:
ImprovesecurityVSAvoidkey management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The key management system is segmented into distinct components: key generation, key distribution, key storage, and key activation. Each component operates independently with well-defined interfaces, reducing overall system complexity while maintaining security. The validity indication mechanism segments the key lifecycle into manageable phases.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Keys are generated and distributed to all communication parties in advance, along with validity indications specifying when each key becomes active. This preliminary action eliminates the need for complex real-time coordination during key changes, as all parties are pre-prepared with the necessary cryptographic material and timing information.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If all communication parties must simultaneously access key change information, then encryption consistency is maintained, but communication reliability deteriorates when parties are unavailable

Engineering Contradiction:
Improveencryption consistencyVSAvoidcommunication reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

A key management server acts as an intermediary that stores and distributes key change information and validity indications to all communication parties independently. This mediator eliminates the need for parties to simultaneously access each other, as each receives information from the centralized server according to its own availability, ensuring both consistency and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The key management server distributes validity indications and key information to all parties in advance of when they are needed. This allows parties to be pre-informed of key changes without requiring simultaneous interaction, maintaining encryption consistency while accommodating individual availability schedules.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If key change operations require confirmation from all parties, then security is maintained, but operational time increases unpredictably when parties are unavailable

Engineering Contradiction:
ImprovesecurityVSAvoidoperational time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

All key material and validity indications are distributed to parties in advance, eliminating the need for time-consuming confirmation operations when key changes are actually needed. The preliminary distribution ensures that when a key change occurs, all parties can immediately use the pre-distributed information without delays.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Each communication party independently processes key changes using pre-distributed validity indications from the key management server, without requiring active confirmation from other parties. This self-service approach maintains security through the validity indication mechanism while eliminating operational delays.

Inventive Principle:
Principle #25Self-service

4Productivity

If encryption keys are shared across a group for communication, then group communication efficiency is improved, but key management complexity increases

Engineering Contradiction:
Improvegroup communication efficiencyVSAvoidkey management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

A single key management server provides universal service to all groups and individuals in the network, handling key generation, distribution, and validity indication management for multiple cryptographic groups simultaneously. This multi-functional approach consolidates complexity into a centralized system while allowing efficient group communication through shared key access.

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

Solution Approach 2:

The system segments cryptographic groups and assigns specific key sets to each group with validity indications. This segmentation allows efficient group communication within defined boundaries while managing complexity through organized, isolated key groups rather than a monolithic key management system.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2215795B1End-to-end encrypted communication
Publication Date: 2016.12.07 AIRBUS DEFENCE & SPACE OY
  • EP2215795B1 patent drawingFigure 1~3
  • EP2215795B1 patent drawingFigure 4~5B
  • EP2215795B1 patent drawingFigure 6~8

AI summary

A method and apparatus for end-to-end encrypted communication. In the user terminal is stored a set of keys applicable in end-to-end encryption of communications. One or more of the keys are associated with a validity indication that indicates a cryptographic group in which the key is to be applied, and a period during which the key is applicable in that particular cryptographic group. When the user terminal connects to communication of the cryptographic group, the key to be applied is selected from the stored set of keys on the basis of the present cryptographic group and the present time according to the associated validity indications.