Encrypted DNN Inference Using Quantization and Integer FHE

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Solution Overview

Problem

Current FHE-based DNN models face significant computational overhead and inefficiencies, particularly with non-linear operations like ReLU and Sigmoid activation functions, making them impractical for real-world applications.

Innovation Solution

A method involving encoding and decoding of messages using quantization parameters, noise-aware fine-tuning, and a modified FHEW-variant DNN model with integer-based computations and functional bootstrapping to enhance efficiency and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Fully Homomorphic Encryption is integrated with Deep Neural Networks, then data security and privacy are improved, but computational overhead and computation time increase significantly

Engineering Contradiction:
Improvedata securityVSAvoidcomputation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies parameter changes by converting the DNN model from floating-point to integer format, adjusting precision parameters, and modifying quantization settings to optimize the balance between security requirements and computational efficiency in the FHE environment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary actions by pre-processing the DNN model before encryption, including model quantization, parameter conversion to integer format, and optimization of computational graphs to minimize FHE overhead during actual inference

Inventive Principle:
Principle #10Preliminary action

2Reliability

If FHE is used for non-linear operations in DNNs, then semantic security is improved, but computational cost and complexity increase

Engineering Contradiction:
Improvesemantic securityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes parameters by converting activation functions to integer-compatible forms, adjusting precision levels, and modifying computational parameters to reduce the complexity of evaluating non-linear operations under FHE while maintaining security guarantees

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes complex floating-point non-linear operations with simplified integer-based approximations and lookup tables that are more efficient in the FHE context, replacing computationally expensive mechanical operations with more suitable integer arithmetic

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

3Reliability

If FHE-based DNN computation is implemented, then data privacy is protected, but productivity and computational efficiency deteriorate

Engineering Contradiction:
Improvedata privacyVSAvoidcomputational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes computational parameters including precision levels, quantization granularity, and integer data types to optimize the trade-off between privacy protection through FHE and computational efficiency for specific application scenarios

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by selectively applying FHE only to critical computational paths and data structures where privacy is most important, rather than encrypting the entire model and all operations uniformly, thus improving overall efficiency

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS12634116B2Inference and conversion method for encrypted deep neural network model
Publication Date: 2026.05.19 INVENTEC PUDONG TECH CORPOARTION
  • US12634116B2 patent drawing
  • US12634116B2 patent drawing
  • US12634116B2 patent drawing

AI summary

An inference method for encrypted deep neural network model is executed by a computing device and includes: encoding a message according to a quantization parameter to generate a plaintext, encrypting the plaintext according to a private key to generate a ciphertext, sending the ciphertext to a deep neural network model to generate a ciphertext result, decrypting the ciphertext result according to the private key to generate a plaintext result, and decoding the plaintext result according to the quantization parameter to generate an inference result.