Physically Secure Memory Partitioning with Hardware Access Boundaries

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Solution Overview

Problem

Existing memory devices are vulnerable to physical attacks and hardware faults that can cause unauthorized access to secure data stored alongside plain data, despite logical separation techniques.

Innovation Solution

Implementing hardware measures such as hardwiring address bus lines, maintaining a large Hamming distance between secure and plain partitions, using a dedicated control signal, and incorporating Error Detection Codes (EDC) to prevent unauthorized access to secure partitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If memory is partitioned into secure and non-secure regions using logical separation techniques, then data storage flexibility is improved, but security against physical attacks deteriorates

Engineering Contradiction:
Improvedata storage flexibilityVSAvoidsecurity against physical attacks
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The memory device is segmented into multiple independent access circuits (first access circuit for secure partition, second access circuit for non-secure partition) that are physically separated and cannot cross-access partitions. This segmentation ensures that even if one access circuit is compromised, the other partitions remain protected.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary control mechanism is introduced that monitors and controls access circuit operations. The system includes control logic that prevents access circuits from generating addresses outside their authorized partition ranges, acting as a mediator between the access circuits and memory partitions to enforce security boundaries.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If access circuits are allowed to generate addresses dynamically for flexible memory access, then access speed is improved, but vulnerability to fault injection attacks increases

Engineering Contradiction:
Improvememory access speedVSAvoidvulnerability to fault injection attacks
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by pre-configuring access circuits with hardwired address range limitations and implementing control logic that proactively prevents address generation outside authorized ranges. This preemptive measure blocks fault injection attacks before they can cause unauthorized access, while still allowing dynamic address generation within safe boundaries.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The invention changes the parameter of address generation by implementing controlled dynamic addressing where access circuits can generate addresses dynamically within their authorized partition ranges, but the address space parameter is constrained by hardware boundaries. This maintains access speed while preventing attacks that rely on generating addresses in unauthorized regions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4322040B1Physically secure memory partitioning
Publication Date: 2025.09.10 WINBOND ELECTRONICS CORP
  • EP4322040B1 patent drawingFigure 1~2
  • EP4322040B1 patent drawingFigure 3

AI summary

A memory device (20) includes a memory (24), a secure-access circuit (36), a plain-access circuit (40), and protection hardware (42). The memory (24) includes at least a secure-storage partition (28) assigned a first address range and a plain-storage partition (32) assigned a second address range, disjoint from the first address range. The secure-access circuit (36) is configured to access the secure-storage partition (28) by generating addresses in the first address range. The plain-access circuit (40) is configured to access the plain-storage partition (32) by generating addresses in the second address range. The protection hardware (42) is configured to prevent the plain-access circuit (40) from accessing the first address range assigned to the secure-storage partition (28).