UWB Secure Ranging via Encrypted Symmetric Key Exchange
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Solution Overview
Problem
Existing UWB communication systems lack efficient methods for securely sharing keys used for encrypting ranging parameters and transferring encrypted ranging data sets, which compromises security and efficiency in UWB secure ranging.
Innovation Solution
A method and device for performing secure ranging by sharing a symmetric key used for encrypting ranging parameters between a UWB subsystem and a secure component, and transferring an encrypted ranging data set from the secure component to the UWB subsystem, with the symmetric key being generated and encrypted by the UWB subsystem.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a symmetric key is generated and encrypted by the UWB subsystem for sharing with a secure component, then encryption security is improved, but device complexity increases due to the need for secure key management and encrypted data transfer protocols
Solution Approach 1:
The system separates key management functions into distinct components: the UWB subsystem generates and encrypts the symmetric key, while the secure component (TEE or SE) stores and manages the encrypted key. This segmentation allows each component to specialize in specific security tasks, improving overall encryption security while distributing complexity across multiple modules rather than concentrating it in one place.
Solution Approach 2:
The patent introduces an intermediary key encryption mechanism where the symmetric key used for ranging parameter encryption is itself encrypted using asymmetric cryptography (public-key infrastructure). This intermediary layer protects the symmetric key during transmission and storage, enhancing security without requiring the symmetric key to be exposed in plaintext within the UWB subsystem.
2Reliability
If an encrypted ranging data set is transferred from a secure component to a UWB subsystem, then ranging security is improved, but transfer time increases due to decryption and verification processes
Solution Approach 1:
The symmetric key is generated and encrypted in advance by the UWB subsystem before the ranging operation begins. The encrypted key is then stored in the secure component during a preliminary setup phase. During the actual ranging operation, the pre-prepared encrypted key can be quickly retrieved and decrypted, reducing the time penalty associated with security verification during critical ranging operations.
Solution Approach 2:
The system maintains continuous security protection throughout the ranging process by keeping the symmetric key encrypted at rest in the secure component and only decrypting it temporarily when needed for ranging parameter encryption. This continuous encryption state minimizes security gaps and allows for efficient key management without repeated encryption/decryption cycles during the ranging operation.
Data Source
AI summary
Disclosed is a method for ultra-wide band (UWB) security ranging and a UWB device configured to perform secure ranging. The method includes obtaining, from a UWB sub-system of the UWB device, first encryption data including a symmetric key encrypted with a public key of a secure application of the UWB device; transferring the first encryption data to the secure application; obtaining, from the secure application, second encryption data including a ranging data set (RDS) encrypted with the symmetric key; and transferring the second encryption data to the UWB sub-system. In this case, the RDS may include a ranging session key configured to secure a UWB ranging session, and the secure application may be included in a trusted execution environment area.