Non-volatile Memory Sense Amplifier Segmentation for Power Analysis Protection

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Solution Overview

Problem

Conventional non-volatile memory devices are vulnerable to Simple Power Analysis (SPA) and Differential Power Analysis (DPA) attacks, where power consumption differences during reading '0' and '1' bits can reveal secret data, and existing protection methods are resource-intensive or ineffective for non-secret data.

Innovation Solution

Dividing word lines of a non-volatile memory device into subsets connected to different sense amplifiers, allowing simultaneous reading of protected data and its inverse copy, while using the same structure for non-protected data to maintain consistent power consumption and prevent SPA/DPA attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If power consumption is measured to read secret data, then data can be obtained, but security is compromised due to SPA/DPA attacks

Engineering Contradiction:
Improvedata reading accuracyVSAvoidpower analysis attack vulnerability
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The memory device is divided into two separate memory devices, each storing a portion of the secret data. The first memory device stores bits at even positions while the second memory device stores bits at odd positions. This segmentation prevents power analysis attacks because measuring power consumption of one device only reveals half of the secret data, making the attack ineffective.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If two memory devices are used to store inverse bit values, then power consumption becomes independent of memory content, but device area increases significantly

Engineering Contradiction:
Improvepower analysis attack resistanceVSAvoidmemory device area
Core Design Contradiction:
Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

Instead of duplicating entire memory devices, the invention segments the secret data storage across two devices by position (even/odd bits). This reduces the area increase compared to full duplication, as each device only needs to store half of the secret data bits rather than complete copies of all data.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different storage strategies to different parts of the memory system. Secret data is stored using the dual-device inverse value method for power analysis protection, while non-secret data can be stored using conventional single-device methods. This local differentiation optimizes area usage by applying protection only where needed.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If sense amplifying device is modified for equal power consumption during reading, then SPA/DPA protection is achieved, but device complexity increases

Engineering Contradiction:
Improvepower analysis attack resistanceVSAvoidsense amplifier complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts the power analysis vulnerability from the memory system by separating secret data storage into two independent devices. Instead of modifying the sense amplifying device to equalize power consumption, the solution removes the source of the problem by ensuring that reading either device alone does not reveal complete secret data, thereby avoiding the need for complex sense amplifier modifications.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If conventional reading method is used for non-secret data, then resource usage is efficient, but security protection is lacking

Engineering Contradiction:
Improvedata readout speedVSAvoidpower analysis attack vulnerability
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention applies different reading methods to different data types within the same memory system. Secret data is read using the secure dual-device method with inverse value storage, while non-secret data is read using conventional efficient methods. This local quality differentiation allows the system to maintain high productivity for non-secret data while ensuring security for secret data.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2133882B1Non-volatile memory device and method for secure readout of protected data
Publication Date: 2015.08.12 EM MICROELECTRONIC-MARIN
  • EP2133882B1 patent drawingFigure 1~2

AI summary

The invention relates to a non - volatile memory device comprising a memory array (16) with multiple memory cells (18) for storing bits of data, the memory cells (18) being arranged in word lines and columns, and a readout circuit (20) for reading out data from the memory array (16). In order to enable an effective use of resources, it is proposed to further provide the non-volatile memory device with at least two sense amplifier devices (22, 24), wherein the sense amplifier devices (22, 24) are connected to respectively different parts of one of the word lines.