Cryptographic Operation Randomization for Side-Channel Attack Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Cryptography algorithms are vulnerable to side-channel attacks that exploit physical phenomena such as execution time and power consumption, which can compromise the security of secret keys.

Innovation Solution

Randomizing the order of operations in cryptographic algorithms, such as those using Number Theoretic Transform (NTT), to reduce predictability and protect against side-channel attacks by updating operation lists based on randomly selected operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cryptographic operations are performed in a fixed order, then execution efficiency is improved, but security against side-channel attacks deteriorates

Engineering Contradiction:
Improveexecution efficiencyVSAvoidsecurity against side-channel attacks
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by making the operation execution order variable rather than fixed. A random number generator dynamically determines the execution sequence of cryptographic operations during each encryption/decryption process, preventing attackers from predicting operation order based on fixed patterns while maintaining execution efficiency through systematic randomization.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of operation execution order from a fixed value to a randomly variable value. By introducing randomness into the execution sequence parameter, the system maintains cryptographic correctness while eliminating predictable patterns that side-channel attacks exploit, thus improving security without sacrificing productivity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If randomization is introduced to protect against side-channel attacks, then security is improved, but execution time variability increases

Engineering Contradiction:
Improvesecurity against side-channel attacksVSAvoidexecution time variability
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-generating random numbers and pre-determining operation execution orders before the actual cryptographic computation. This preparation phase allows the randomized execution to proceed smoothly during the main computation, minimizing execution time variability while maintaining security benefits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent substitutes the mechanical deterministic execution sequence with a randomized selection mechanism. Instead of following a fixed mechanical order of operations, the system uses random number generation to select execution order, replacing predictable mechanical behavior with probabilistic control that reduces time variability patterns exploitable by side-channel attacks.

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

Data Source

PatentEP4407589A1Apparatus and method for cryptography secure against side-channel attacks
Publication Date: 2024.07.31 SAMSUNG ELECTRONICS CO LTD
  • EP4407589A1 patent drawingFigure 1
  • EP4407589A1 patent drawingFigure 2
  • EP4407589A1 patent drawingFigure 3

AI summary

A method of performing a plurality of operations, the plurality of operations including a plurality of first operations and at least one second operation dependent on the plurality of first operations, the method including randomly selecting a first operation from a first operation list, the first operation list including at least one first operation, among the plurality of first operations, for which operands are prepared, generating a first result by performing the randomly selected first operation, and updating the first operation list based on the randomly selected first operation.