Double Encryption Using AES and High-Entropy XOR Sequences

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing encryption technologies, such as AES, may not provide long-term security against unauthorized decryption, especially when data passes through multiple nodes, as keys can potentially be compromised over time.

Innovation Solution

A device employing symmetric encryption using the Advanced Encryption Standard (AES) and an additional layer of encryption with a bit sequence of maximum entropy through the XOR method, ensuring that even if AES encryption is compromised, the double-encrypted data remains secure due to its high entropy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data is encrypted using AES symmetric encryption, then the data can be securely transmitted, but the encryption may be compromised over time (approximately 30 years) by unauthorized persons with the necessary key

Engineering Contradiction:
Improvelong-term securityVSAvoidtime until decryption possible
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent divides the encryption process into two independent stages: first AES symmetric encryption, then XOR encryption with a high-entropy bit sequence. This segmentation creates layered security where compromising one layer (AES) does not automatically compromise the other (XOR), thereby extending the effective security duration beyond what either method could achieve alone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines two different encryption methods (AES and XOR) into a composite encryption system. The AES encryption provides structured security while the XOR encryption with maximum entropy bit sequence adds randomness-based security. This composite approach creates a system that resists both cryptographic attacks and brute-force attacks, significantly extending the time required for unauthorized decryption.

Inventive Principle:
Principle #40Composite materials

2Reliability

If a new key is generated for each encryption (dynamic key generation), then key confidentiality is improved, but the complexity of key management increases

Engineering Contradiction:
Improvekey confidentialityVSAvoidkey management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a deterministic key derivation mechanism where the XOR encryption key is generated from a seed value and counter through a hash function. This self-service approach automatically generates unique keys for each encryption operation without requiring manual key distribution or complex key management infrastructure, maintaining high key confidentiality while avoiding increased operational complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the key generation parameters by using a combination of a fixed seed value and an incrementing counter. This parameter change strategy ensures that each encryption operation uses a unique key (improving confidentiality) while the deterministic nature of the derivation process keeps the key management mechanism simple and automated.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a bit sequence with maximum entropy is used for XOR encryption, then the security against unauthorized decryption is significantly enhanced, but the requirement for high-quality random data increases

Engineering Contradiction:
Improvesecurity against decryptionVSAvoidgeneration of high-entropy data
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the need for complex hardware random number generators with a software-based deterministic random bit generator using hash functions. This substitution achieves maximum entropy output through cryptographic hashing of seeded data, providing high security without the manufacturing complexity and cost associated with physical random number generation devices.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the challenge of generating high-entropy data by changing from physical random generation to cryptographic pseudo-random generation. By using hash functions with appropriate seed parameters, the system achieves maximum entropy characteristics computationally, avoiding the manufacturing difficulties of physical random number generators while maintaining strong security properties.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2288073B1Apparatus for encrypting data
Publication Date: 2013.07.31 COMPUGRP MEDICAL SE
  • EP2288073B1 patent drawingFigure 1
  • EP2288073B1 patent drawingFigure 2
  • EP2288073B1 patent drawingFigure 3

AI summary

The device (102-i) has a unit for symmetric encryption of data and another unit for encrypting symmetrically encrypted data using bit sequences (112,114-1 to 114-n). The bit sequence has maximum entropy. The unit for encrypting the symmetrically encrypted data is so designed that a portion of the bit sequence is used for encryption. Successive encryption is executed with varying portion of the bit sequence. The bit sequence remains unchanged. An independent claim is also included for a computer program product, particularly digital storage medium for encrypted communication over a transmission medium.