Memory Key Search Circuit Buffering for Encryption Latency

Solution Overview

Problem

Current memory systems with data encrypting functions face challenges in reducing the time required to search for encryption keys, which hinders I/O throughput and increases latency due to the need to manage a large number of encryption keys for each logical block address range.

Innovation Solution

A memory system with a key search circuit that utilizes a range table and a search result buffer to quickly retrieve access control information and encryption keys, allowing for immediate access when a key search request matches a stored result, thereby reducing the need to constantly refer to the range table.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large number of encryption keys are managed for each logical block address range, then data security is improved, but key search time increases and I/O throughput decreases

Engineering Contradiction:

Improvedata securityVSAvoidI/O throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system pre-loads encryption keys and access control information into a buffer memory before they are needed for actual data operations. The key search circuit queries the buffer in advance or concurrently with data access requests, so that when data I/O operations need to occur, the corresponding encryption keys are already available in the buffer, eliminating the bottleneck of real-time key searching from the critical data path.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A dedicated key search circuit and buffer memory are introduced as intermediary components between the data I/O path and the encryption key storage. This intermediary layer handles key retrieval operations separately, allowing the main data transmission path to operate independently without being blocked by key search delays.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a large number of encryption keys are managed for each logical block address range, then data security is improved, but key search latency increases

Engineering Contradiction:

Improvedata securityVSAvoidkey search latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system pre-loads encryption keys and access control information into a buffer memory before they are needed for actual data operations. The key search circuit queries the buffer in advance or concurrently with data access requests, so that when data I/O operations need to occur, the corresponding encryption keys are already available in the buffer, eliminating the bottleneck of real-time key searching from the critical data path.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of directly accessing the full range table containing all encryption keys for every logical block address range, the system maintains a buffered copy of the frequently accessed key information. The key search circuit queries this smaller, faster buffer memory which contains replicated or pre-fetched key data, significantly reducing search latency compared to querying the complete range table.

Inventive Principle:

Principle #26Copying

3Measurement precision

If the range table is frequently queried for key search requests, then accurate key retrieval is ensured, but system performance decreases

Engineering Contradiction:

Improvekey retrieval accuracyVSAvoidsystem performance

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

A dedicated key search circuit and buffer memory are introduced as intermediary components between the data I/O path and the encryption key storage. This intermediary layer handles key retrieval operations separately, allowing the main data transmission path to operate independently without being blocked by key search delays.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of directly accessing the full range table containing all encryption keys for every logical block address range, the system maintains a buffered copy of the frequently accessed key information. The key search circuit queries this smaller, faster buffer memory which contains replicated or pre-fetched key data, significantly reducing search latency compared to querying the complete range table.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS11726924B2Memory system for data encryption

Publication Date: 2023.08.15 KIOXIA CORP

AI summary

According to one embodiment, a key search circuit includes a hit determination circuit that determines whether a key search request hits a content stored in a search result buffer, and an update determination circuit that determines whether to update the content stored in the search result buffer. When the hit determination circuit determines that the key search request hits the search result buffer, the key search circuit outputs the search result stored in the search result buffer to an encryption/decryption circuit. When the update determination circuit determines to update the search result buffer, the key search circuit updates the content stored in the search result buffer with the key search request and a search result obtained from a range table.