Decryption Keystream Pre-generation for Flash Data Processing
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Solution Overview
Problem
The challenge is to reduce data decryption delay in embedded system-on-a-chip (SoC) products that use external flash storage, as existing methods do not efficiently decrypt data quickly enough for immediate execution by the microcontroller unit (MCU).
Innovation Solution
A data processing method that generates a decryption keystream based on the physical start address of the data before or during reading, allowing for pre-generation of the keystream, which is then used to decrypt the data using an XOR operation, thereby reducing decryption delay. This method also synchronizes encryption and decryption keystreams for efficient data processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data decryption is performed after reading from external FLASH, then data security is maintained, but data decryption delay increases
Solution Approach 1:
The patent applies preliminary action by pre-generating the decryption keystream based on the physical start address of the data block before the actual decryption process. The keystream generation occurs in advance during the data reading operation, so that when the encrypted data arrives, the decryption key is already ready, eliminating the delay that would otherwise occur during the decryption phase.
2Use of energy by moving object
If decryption keystream is generated after data reading, then computational resources are saved, but decryption speed decreases
Solution Approach 1:
The patent performs preliminary action by generating the decryption keystream in advance based on the physical start address. This pre-computation ensures that when decryption is needed, the keystream is already available, thus improving decryption speed without requiring additional computational resources at the critical decryption moment.
Solution Approach 2:
The patent introduces an intermediary mechanism where the physical start address serves as the basis for generating the decryption keystream. This intermediary approach allows the system to prepare decryption keys in advance using address information that is already available during the data reading process, bridging the gap between data retrieval and decryption operations.
3Productivity
If data is decrypted immediately upon reading, then execution speed improves, but system complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-generating the decryption keystream during the data reading phase. This approach enables immediate decryption upon data arrival, improving processing efficiency while keeping the system relatively simple by reusing existing address information rather than introducing complex key management infrastructure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution significantly reduces data decryption delay by pre-generating the decryption keystream, enabling direct decryption of data and improving overall data processing efficiency, especially in embedded SoC systems with XIP functionality.
Implementation Method 1
performing an XOR operation on the decryption keystream and the first data to decrypt the first data
Data Source
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AI summary
The present application provides a data processing method, a circuit, a terminal device and a storage medium, which includes: generating a decryption keystream of first data according to a physical start address of the first data before or during reading the first data from a flash; and decrypting the first data through the decryption keystream and writing the decrypted first data into a cache, thus the data decryption delay can be reduced.