User Equipment Physical-Layer Keys for Explicit Roaming Authentication

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Solution Overview

Problem

Existing wireless communication systems face security risks during roaming due to implicit network authentication, which relies heavily on key confirmation, leading to potential replay attacks and breaches in unlinkability and location confidentiality.

Innovation Solution

Implementing a method where user equipment determines a physical layer key based on wireless channel characteristics, receives authentication codes, and authenticates the serving network explicitly using these keys, while the home network generates random numbers to enhance security and avoid SQN synchronization issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If implicit authentication is used during roaming, then the authentication process is simple, but network security deteriorates due to reliance on key confirmation

Engineering Contradiction:

Improveauthentication process simplicityVSAvoidnetwork security

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent replaces the mechanical/key-based implicit authentication system with a cryptographic system that uses physical layer characteristics (channel state information, reference signals) to generate authentication keys. This substitution transforms the authentication mechanism from simple key confirmation to a more secure physical-layer-based explicit authentication, resolving the contradiction between simplicity and security

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the authentication parameter from traditional key-based confirmation to physical layer parameters such as channel state information, reference signal received power, and signal characteristics. By changing these fundamental parameters, the system achieves both simplified operation (through automatic physical layer key derivation) and enhanced security (through physical layer authentication)

Inventive Principle:

Principle #35Parameter changes

2Reliability

If SQN mechanism is adopted for synchronization, then authentication can be performed, but replay attacks become possible due to SQN synchronization loss

Engineering Contradiction:

Improveauthentication capabilityVSAvoidreplay attack risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the SQN (sequence number) mechanism from the authentication process and replaces it with physical layer-based authentication keys derived from channel characteristics. By removing the SQN element, the system eliminates the vulnerability to replay attacks while maintaining authentication capability through physical layer key derivation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of replay attacks into a benefit by using physical layer characteristics that are inherently difficult to replicate. The channel state information and reference signal characteristics serve as natural authentication vectors that prevent replay attacks, turning the vulnerability into a security feature

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If key confirmation is relied upon for authentication, then the process is straightforward, but security risks increase due to potential key compromise

Engineering Contradiction:

Improveauthentication processVSAvoidsecurity risks

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces physical layer characteristics (channel state information, reference signals) as an intermediary between the user equipment and the authentication process. This intermediary generates authentication keys that are derived from physical measurements rather than relying on pre-shared keys, thereby reducing security risks while maintaining operational simplicity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent substitutes the traditional key confirmation mechanism with a physical layer-based key derivation mechanism. This substitution uses channel characteristics and reference signals to generate authentication keys, replacing the vulnerable key confirmation process with a more secure physical layer authentication system

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS20250254517A1User equipment, electronic device, wireless communication method, and storage medium

Publication Date: 2025.08.07 SONY GROUP CORP

AI summary

The present disclosure relates to a user equipment, an electronic device, a wireless communication method, and a storage medium. The user equipment according to the present disclosure comprises a processing circuit configured to: determine a physical layer key according to features of a wireless channel between the user equipment and a serving network; receive a serving network message authentication code and a home network authentication token from the serving network; determine an authentication parameter according to the physical layer key and the home network authentication token; and authenticate the serving network according to the authentication parameter and the serving network message authentication code. By using the user equipment, electronic device, wireless communication method, and storage medium according to the present disclosure, an authentication process in a scenario where the user equipment roams can be optimized.