Real-Time Soft Combining Decrypted Bluetooth Payloads
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Solution Overview
Problem
Conventional methods for real-time soft combining of Bluetooth transmissions and retransmissions fail when using a unique nonce for each message, as it scrambles the encrypted data, making it impossible to combine encrypted data for CRC validation.
Innovation Solution
The solution involves decrypting and re-encrypting the received data stream on the fly to enable real-time soft combining of decrypted payloads and CRC verification, with dynamic selection and prefetching of encryption keys based on logical links to facilitate continuous data correction and validation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a unique nonce is used for each message in Bluetooth transmissions, then message integrity and security are improved, but real-time soft combining of encrypted data becomes impossible
Solution Approach 1:
The patent introduces a decryption intermediary layer that converts encrypted packets with unique nonces into decrypted packets, enabling soft combining. The system decrypts each packet using its unique nonce, combines the decrypted payloads, and then encrypts the combined result using a shared nonce for CRC validation, thus resolving the contradiction between unique nonce security and soft combining capability
Solution Approach 2:
The patent segments the packet processing into distinct stages: decryption stage (using unique nonces for security), combining stage (using decrypted payloads for error correction), and validation stage (using encrypted combined data with shared nonce for CRC). This segmentation allows each stage to optimize for its specific requirement, resolving the contradiction
2Reliability
If real-time soft combining is performed on encrypted data, then data correction capability is improved, but CRC validation becomes impossible due to unique nonces
Solution Approach 1:
Instead of combining encrypted data directly (conventional approach), the patent inverts the process by first decrypting the data, then combining the decrypted payloads, and finally encrypting the combined result for CRC validation. This inversion enables both data correction and valid CRC verification to coexist
3Ease of manufacture
If decrypted data is used for soft combining, then combining capability is improved, but CRC validation fails because encrypted CRC is based on encrypted data
Solution Approach 1:
The patent performs preliminary decryption of each received packet before combining, so that the combining operation works on clean decrypted data. After combining, the system then encrypts the combined result and validates the encrypted CRC, ensuring both combining capability and validation reliability are achieved
Data Source
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AI summary
In one example herein, apparatus and methods enable continuously combining the contents of each transmitted message and subsequent retransmitted message even when a unique nonce is used for each encrypted message. The received data stream is decrypted and re-encrypted on the fly to meet all the requirements of real-time soft combining of the decrypted payload and the validation of the encrypted CRC. In another example, the currently received message payload is decrypted on the fly so that it can be soft-combined in real time with previously decrypted messages. The corrected message payload is re-encrypted on the fly so that the CRC verification can be performed on combined encrypted data.