Secure MAC Header Encryption via Segmented Key Management

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Solution Overview

Problem

Wireless communication systems face security and privacy issues due to unencrypted fields in the medium access control (MAC) header, making them vulnerable to denial-of-service attacks and privacy breaches, as fields like sequence number, traffic identifier, power management, and high-throughput control are sent in clear and not adequately protected.

Innovation Solution

Proposing the encryption of specific MAC header fields using an additional key different from the key used for data and management frames, with the additional key maintained in the lower layer to facilitate reencryption without involving higher layers, thus enhancing security and privacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If MAC header fields are transmitted in clear text to maintain simplicity and compatibility, then device complexity and implementation ease are improved, but security and privacy are worsened due to vulnerability to denial-of-service attacks and privacy breaches

Engineering Contradiction:
Improveimplementation easeVSAvoidsecurity vulnerability
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The MAC header is segmented into two parts: unencrypted fields (frame control, duration, addresses) that maintain compatibility and simplicity, and encrypted fields (sequence number, traffic identifier, power management, high-throughput control) that provide security. This segmentation allows the system to achieve both ease of implementation and enhanced security by only encrypting the vulnerable portions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the MAC header have different security properties. The patent applies encryption selectively to specific fields that are vulnerable to attacks, while leaving other fields unencrypted to maintain simplicity. This local differentiation of security quality resolves the contradiction between overall simplicity and security protection.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If all MAC header fields are encrypted to enhance security, then security and privacy are improved, but device complexity and processing overhead increase

Engineering Contradiction:
Improvesecurity protectionVSAvoidprocessing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the MAC header into encrypted and unencrypted portions, encrypting only the vulnerable fields (sequence number, traffic identifier, power management, high-throughput control) while leaving other fields unencrypted. This reduces processing complexity compared to encrypting the entire header, while still providing security protection where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of encrypting all MAC header fields (excessive action), the patent applies encryption only to the partial set of fields that are actually vulnerable to attacks. This partial action approach provides sufficient security protection while minimizing the increase in processing complexity.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If MAC header fields are encrypted using the same key as data frames, then key management simplicity is improved, but security is worsened due to lack of differentiation and potential key reuse vulnerabilities

Engineering Contradiction:
Improvekey management complexityVSAvoidsecurity weakness
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the key management system into two separate keys: a first key for encrypting data frames and a second key for encrypting MAC header fields. This segmentation prevents key reuse vulnerabilities and provides differentiated security for different types of data, while the patent notes that the second key can be derived from the first key to manage complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different encryption keys are applied to different data types: the first key for data frame encryption and the second key for MAC header field encryption. This local differentiation of key quality provides enhanced security by ensuring that sensitive control fields in the MAC header are protected with appropriate cryptographic keys.

Inventive Principle:
Principle #3Local quality

4Ease of operation

If MAC header fields are made immutable to simplify processing, then processing simplicity is improved, but adaptability is worsened due to inability to modify fields like sequence number and traffic identifier during retransmissions

Engineering Contradiction:
Improveprocessing simplicityVSAvoidfield modification capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamic encryption to MAC header fields that need to be modified during retransmissions. The encrypted fields (sequence number, traffic identifier, power management, high-throughput control) can be dynamically updated and reencrypted, allowing the system to adapt to different transmission conditions while maintaining processing simplicity through automated reencryption operations.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4293963A1Secure medium access control (MAC) header
Publication Date: 2023.12.20 INTEL CORP
  • EP4293963A1 patent drawingFigure 1
  • EP4293963A1 patent drawingFigure 2A~2B
  • EP4293963A1 patent drawingFigure 3A~3C

AI summary

This disclosure describes systems, methods, and devices related to secure medium access control (MAC) header. A device may generate a frame comprising one or more fields that are encrypted using a second encryption key different from a first encryption key used in a frame body of a data frame or a management frame. The device may cause to send the frame to one or more station devices (STAs).