Storage Controller Cryptographic Erase Verification

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Solution Overview

Problem

Current data sanitization methods, particularly cryptographic erase, lack reliability in verifying the deletion of media encryption keys (MEKs) in storage devices, making it difficult to ensure secure disposal or reuse of storage devices.

Innovation Solution

A storage device with a nonvolatile memory (NVM) and a storage controller that receives a command for cryptographic erase, generates and transmits verification values indicating whether the MEK has been deleted and a new MEK has been generated, ensuring reliable sanitization operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If cryptographic erase is used to sanitize data, then data security is improved, but reliability of verification is worsened

Engineering Contradiction:

Improvedata securityVSAvoidverification reliability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the storage controller generates verification values (first and second verification values) that provide feedback to the host device about the status of MEK deletion and regeneration. This allows the host to verify whether the cryptographic erase operation was successfully completed, resolving the reliability issue while maintaining data security through the cryptographic erase method itself.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The storage controller performs preliminary actions by generating verification values before the host device needs to verify the sanitization status. The controller proactively prepares and transmits the first verification value (indicating MEK deletion) and second verification value (indicating new MEK generation) to the host, enabling reliable verification without requiring complex post-operation checking procedures.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If verification values are transmitted to confirm MEK deletion, then sanitization reliability is improved, but communication overhead is worsened

Engineering Contradiction:

Improvesanitization reliabilityVSAvoidcommunication data volume

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The verification mechanism uses localized quality by transmitting only specific verification values (first and second verification values) that are directly relevant to confirming MEK deletion and regeneration, rather than transmitting all possible status information. This minimizes communication overhead while maintaining sanitization reliability by focusing only on the critical verification data needed.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12014059B2Storage devices, methods of operating storage devices, and methods of operating host devices

Publication Date: 2024.06.18 SAMSUNG ELECTRONICS CO LTD

AI summary

A storage device, a method of operating the storage device, and a method of operating a host device are provided. The storage device includes a nonvolatile memory (NVM) and a storage controller controlling the nonvolatile memory. The storage controller is configured to receive a command from a host device giving instructions to sanitize data with the use of a cryptographic erase. The storage controller is also configured to, in response to a request from the host device, transmit to the host device a first verification value indicative of whether a first media encryption key (MEK) stored in the NVM has been deleted and a second verification value indicative of whether a second MEK, which is different from the first MEK, has been generated and stored in the NVM.