Threshold Keystore Shredding via Stable System Values
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shredding schemes in data encryption key management are problematic due to reliance on a wrapping key (KEK) and Data Encryption Key (DEK), where loss of KEK storage can render DEKs inaccessible and temporary exposure of DEKs in plaintext occurs during re-wrapping, lacking redundancy and security.
Innovation Solution
A method involving a keystore with a threshold of stable system values, stored across different locations, including electrically erasable programmable read-only memory and self-encrypting hard drives, where more than the threshold number of stable system values can be deleted to ensure secure deletion and regeneration of new values, avoiding the need for re-wrapping all DEKs with a new KEK.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a wrapping key (KEK) and Data Encryption Key (DEK) scheme is used for shredding, then key management is simplified, but redundancy is lost and security is compromised when KEK storage is lost
Solution Approach 1:
The system segments the KEK into multiple separate DEKs, where each DEK stores a portion of the wrapped KEK material. No single DEK contains the complete KEK, so loss of one DEK does not compromise the entire key management system. The KEK is reconstructed by combining multiple DEKs when needed.
Solution Approach 2:
The patent introduces an intermediary mechanism using multiple DEKs that act as mediators between the storage system and the master KEK. These DEKs collectively hold the wrapped KEK material and can reconstruct it through a threshold mechanism, providing an intermediate layer that enhances both reliability and security.
2Reliability
If DEKs are rewrapped with a new KEK, then security is updated, but DEKs are temporarily exposed in plaintext in memory
Solution Approach 1:
The system performs preliminary actions by pre-computing and storing multiple DEKs with wrapped KEK material before any rewrapping operation is needed. When security updates are required, the system can directly replace or regenerate DEKs without temporarily exposing the master KEK in plaintext, as all necessary key material is already in wrapped form across multiple DEKs.
3Reliability
If the old KEK is erased after rewrapping, then security is improved, but redundancy is lost and DEKs cannot be unwrapped if memory is lost
Solution Approach 1:
The system creates multiple copies of the wrapped KEK material distributed across multiple DEKs rather than storing a single KEK that can be erased. Each DEK contains a portion of the wrapped key material, and the system maintains redundancy by keeping multiple DEKs instead of a single erasable KEK storage location.
Solution Approach 2:
The patent implements beforehand cushioning by maintaining multiple DEKs with wrapped KEK material as a backup mechanism. Even if some DEKs are lost or corrupted, the system retains sufficient wrapped key material in remaining DEKs to reconstruct the KEK and access protected data, providing a safety cushion against information loss.
Data Source
AI summary
A method, computer program product, and computer system for storing, by a computing device, a data encryption key in a keystore. A plurality of stable system values may be generated, wherein a threshold number of the plurality of stable system values is required to access the data encryption key from the keystore. The plurality of stable system values may be stored in different locations. More stable system values of the plurality of stable system values than the threshold number of the plurality of stable system values required to access the data encryption key from the keystore may be deleted.