DRAM Memory Security via Auto Refresh Validation

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Solution Overview

Problem

Current data security techniques for DRAM devices are resource-intensive and time-intensive, and they fail to effectively address residual charges in capacitors that can allow unauthorized access to sensitive data.

Innovation Solution

Implementing refresh-based security techniques that halt or delay refreshing operations in response to unauthorized access attempts, using validation circuitry to detect and prevent unauthorized access by stopping internal refresh operations, thereby protecting data stored in DRAM memory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If body biasing or power ramp techniques are used to wipe data, then data security is improved, but the process becomes time-intensive and resource-intensive

Engineering Contradiction:

Improvedata securityVSAvoidtime-intensive process

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by continuously monitoring refresh operations and detecting unauthorized access attempts before data can be compromised. The system proactively halts refresh operations and triggers security responses (power ramp, body biasing) before residual charges can be exploited, rather than reacting after an attack is detected

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies skipping by rapidly transitioning from normal refresh operations to security response modes when unauthorized access is detected. The system rushes through the security response process by immediately halting refreshes and executing power ramp or body biasing techniques without delay, reducing the time window for potential attacks

Inventive Principle:

Principle #21Skipping (Rushing through)

2Reliability

If body biasing or power ramp techniques are used to wipe data, then data security is improved, but the process becomes resource-intensive

Engineering Contradiction:

Improvedata securityVSAvoidresource-intensive process

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by selectively applying security measures only to specific memory regions or banks that are targeted by unauthorized access attempts, rather than wiping or biasing the entire memory array. This reduces energy consumption while maintaining security for the affected data

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system implements self-service by automatically detecting unauthorized access attempts and triggering appropriate security responses without requiring external intervention. The memory device monitors its own refresh operations and autonomously executes power ramp or body biasing sequences when threats are detected, reducing the need for external resource management

Inventive Principle:

Principle #25Self-service

3Reliability

If reactive data erasure techniques are used, then data security is addressed, but they are susceptible to internal capacitances that continue to store data after power removal

Engineering Contradiction:

Improvedata securityVSAvoidresidual charges in capacitors

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by halting refresh operations and applying counter-voltages through power ramp or body biasing techniques before residual charges can be accessed or leaked. This preemptive approach neutralizes the harmful effect of capacitor residual charges by disrupting the voltage levels before unauthorized access can occur

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent converts the harmful residual charges in capacitors into a security feature by using the inherent capacitance to maintain voltage levels during security responses. The residual charges are utilized to sustain power ramp or body biasing sequences, turning a potential vulnerability into an asset for enforcing security measures

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Ease of operation

If refresh operations continue during unauthorized access, then memory functionality is maintained, but data security is compromised

Engineering Contradiction:

Improvememory functionalityVSAvoiddata security

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making refresh operations conditional based on security status. The system dynamically adjusts refresh behavior - continuing normal refreshes during authorized operation but halting them immediately when unauthorized access is detected. This dynamic control allows the memory to transition between functional and secure states based on real-time conditions

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10665290B1Memory security techniques using auto refresh validation

Publication Date: 2020.05.26 MICRON TECHNOLOGY INC

AI summary

Techniques described herein are related to protecting at least a portion of data stored in a memory array. A method may include detecting an invalid memory access request based at least in part on the secret key and the identifier and preventing unauthorized access of a memory array by halting an internal refresh of one or more memory cells associated with the memory array in response to detecting the invalid memory access request.