Alternating Block Chaining Encryption for Encrypted File Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Encrypted File Systems (EFS) face inefficiencies and security vulnerabilities due to the need for extensive decryption and re-encryption of files upon modification, particularly with ECB encryption, which is also susceptible to cryptanalysis.
Innovation Solution
The implementation of an Alternating Block Chaining (ABC) encryption methodology, which alternates between Plaintext Block Chaining (PBC) and Cipher Block Chaining (CBC) encryption methods for each block of data, reducing the number of blocks that need to be decrypted and re-encrypted upon modification to three, including the modified block, and utilizing a single initialization vector for an entire file.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If ECB encryption is used in Encrypted File Systems, then encryption speed is improved, but security is worsened due to susceptibility to cryptanalysis
Solution Approach 1:
The patent combines multiple encryption methodologies (ECB, CBC, CFB) into a composite encryption approach, where different modes are applied to different portions of data based on a salt value. This allows the system to maintain the speed advantages of ECB for certain data portions while using more secure CBC or CFB modes for others, thereby achieving both high encryption speed and improved security resistance against cryptanalysis.
2Reliability
If more secure encryption methodologies are used, then security is improved, but performance is worsened due to extensive decryption and re-encryption requirements
Solution Approach 1:
The patent segments the encrypted file into multiple portions, each encrypted with a different encryption mode (ECB, CBC, or CFB) determined by a salt value derived from the file name and extension. This segmentation allows individual blocks to be decrypted and modified independently without requiring re-encryption of the entire file, thereby maintaining high security while preserving performance during file modifications.
Solution Approach 2:
Different portions of the same file are encrypted with different encryption methodologies tailored to their specific needs. The salt value determines which encryption mode is applied to each portion, allowing the system to optimize security for critical data portions while maintaining faster encryption speeds for less sensitive portions, thus achieving high overall security without uniform performance degradation.
3Ease of operation
If ECB encryption is used, then modification of file portions is simplified, but security is worsened due to vulnerability to known plaintext attacks
Solution Approach 1:
The patent introduces a salt value as an intermediary element that determines the encryption mode for each file portion. This salt is derived from the file name and extension, creating a unique encryption configuration for each file without requiring complex user intervention. The salt acts as a mediator that automatically selects between ECB, CBC, and CFB modes, maintaining ease of operation while significantly improving security against known plaintext attacks.
Data Source
Figure 1~3
Figure 2
Figure 4~5
AI summary
An encryption apparatus and method for providing an encrypted file system are provided. The encryption apparatus and method of the illustrative embodiments uses a combination of encryption methodologies so as to reduce the amount of decryption and re-encrypt ion that is necessary to a file in the Encrypted File System in the event that the file needs to be modified. The encryption methodologies are interleaved, or switched, with regard to each block of plaintext. In one illustrative embodiment, Plaintext Block Chaining (PBC) and Cipher Block Chaining (CBC) encryption methodologies are alternated for encrypting a sequence of blocks of data. The encryption of a block of plaintext is dependent upon the plaintext or a cipher generated for the plaintext of a previous block of data in the sequence of blocks of data so that the encryption is more secure than known Electronic Code Book encryption methodologies.