Dynamic Key Encryption for Cache Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing encryption methods for cache structures, such as branch prediction buffers, face challenges in maintaining security without increasing latency, particularly when using a fixed key that can be determined over time.
Innovation Solution
A data processing apparatus and method that employs storage circuitry, communication circuitry, coding circuitry, and update circuitry to perform encoding and updating operations using execution environment-specific keys, ensuring secure data access without significant latency increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed key is used for encryption of cache structures, then the implementation is simple and latency is low, but the security is reduced because the key can be determined over time
Solution Approach 1:
The patent applies dynamics by transitioning from a static fixed key to a dynamic key that changes based on execution context. The key is now derived from the combination of a base key and execution context identifier, allowing the encryption key to adapt to different execution environments while maintaining security without significantly increasing latency.
Solution Approach 2:
The patent changes the parameters of the encryption key by incorporating the execution context identifier into the key derivation process. This parameter change allows the same base key to produce different effective keys for different execution contexts, improving security while keeping the implementation efficient.
2Reliability
If encryption is applied to cache structures, then security is improved, but the access latency increases
Solution Approach 1:
The patent applies preliminary action by pre-computing and storing the encoded index values in the cache structure. When access is needed, the system only needs to retrieve and decode the pre-encoded index rather than performing complex encryption operations in real-time, thus maintaining fast access speed while ensuring security.
Solution Approach 2:
The patent extracts the encryption operation from the critical data access path by pre-encoding indices during cache insertion. The encryption/decryption operations are performed separately from the main access flow, allowing the cache to operate at full speed while still providing encrypted storage.
Data Source
AI summary
A data processing apparatus is provided that includes storage circuitry. Communication circuitry responds to an access request comprising a requested index with an access response comprising requested data. Coding circuitry performs a coding operation using a current key to: translate the requested index to an encoded index of the storage circuitry at which the requested data is stored or to translate encoded data stored at the requested index of the storage circuitry to the requested data. The current key is based on an execution environment. Update circuitry performs an update, in response to the current key being changed, of: the encoded index of the storage circuitry at which the requested data is stored or the encoded data.