Functional-Safe SHA Hash Block for Quantum-Resistant Signatures

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing public-key digital signature algorithms like RSA and ECDSA are not secure against brute-force attacks from quantum computers, necessitating the development of post-quantum cryptography solutions such as hash-based signatures to ensure secure data communication and storage.

Innovation Solution

The implementation of hash-based signature schemes like XMSS and LMS, which utilize one-time signature algorithms and secure hash functions like SHA2-256 and SHA3, along with Merkle trees for robust state synchronization and single-use private key management to prevent signature forgery, ensuring secure and quantum-resistant digital signatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hash-based signature schemes are implemented to provide quantum resistance, then security against quantum attacks is improved, but device complexity increases due to the need for Merkle trees and state synchronization mechanisms

Engineering Contradiction:
Improvesecurity against quantum attacksVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system is divided into distinct functional modules: a hash-based signature generation module that creates one-time signatures, a Merkle tree construction module that organizes public keys, and a state synchronization module that manages key usage. This segmentation allows each component to be optimized independently while maintaining overall security against quantum attacks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Merkle trees are constructed in advance during key generation, organizing all public keys before signing operations begin. This preliminary structuring enables efficient verification and state synchronization during actual signing operations, reducing real-time computational complexity while maintaining quantum resistance.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If one-time signature algorithms are used to ensure security, then security against quantum attacks is improved, but productivity decreases due to the inability to reuse private keys

Engineering Contradiction:
Improvesecurity against quantum attacksVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system employs a universal Merkle tree structure that can accommodate multiple one-time signature pairs under a single public key. This allows the system to maintain the security properties of one-time signatures while enabling multiple signing operations through state synchronization, effectively bridging the gap between security requirements and productivity needs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a state synchronization mechanism that acts as an intermediary between the one-time signature algorithm and multi-use requirements. This mediator tracks key usage states and enables secure key management, allowing systems to benefit from both the quantum resistance of one-time signatures and the productivity of reusable key pairs.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If Merkle trees are implemented for state synchronization, then reliability is improved through better key management, but device complexity increases

Engineering Contradiction:
Improvestate synchronizationVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extends the traditional Merkle tree structure by adding a state synchronization dimension that tracks key usage across multiple devices and time periods. This additional dimensional layer enables comprehensive key management and security auditing without fundamentally changing the core Merkle tree algorithm, allowing systems to gain enhanced reliability while managing complexity through structured extension rather than complete redesign.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4020874A1Efficient quantum-attack resistant functional-safe HASH building block
Publication Date: 2022.06.29 INTEL CORP
  • EP4020874A1 patent drawingFigure 1A~1B
  • EP4020874A1 patent drawingFigure 2A
  • EP4020874A1 patent drawingFigure 2B

AI summary

An apparatus comprises an input register comprising a state register and a parity field, a first round secure hash algorithm (SHA) datapath communicatively coupled to the state register, comprising a first section to perform a θ step of a SHA calculation, a second section to perform a p step and a p step of the SHA calculation, a third section to perform a χ step of the SHA calculation and a fourth section to perform a t step of the SHA calculation.