Trojan Neural Network Detection via Adversarial Perturbation

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Solution Overview

Problem

Current methods for detecting Trojan neural networks are inadequate, especially in data-limited or data-free environments, as they require access to training or test data and are sensitive to trigger size and quality, making them impractical for ensuring model trustworthiness in online scenarios.

Innovation Solution

The proposed solution involves generating adversarial perturbations to identify neuron activations and maximize them, allowing for the detection of Trojan models without access to clean data, using a data-limited TrojanNet detector (DL-TND) and a data-free TrojanNet detector (DF-TND), which leverage universal and per-sample perturbations to reveal trigger patterns and detect poisoned models efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current detection methods are used, then detection capability is provided, but access to training or test data is required and sensitivity to trigger size and quality occurs

Engineering Contradiction:
Improvemodel trustworthinessVSAvoiddata access requirement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts the detection capability from the context of requiring training or test data. By formulating detection as an optimization problem that operates on the model itself without external data, it removes the data access requirement while maintaining detection reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The detection method performs self-service by using the model's own internal representations and computations to detect Trojan triggers. The method leverages the model's forward propagation mechanics and neuron activations without requiring external training or test datasets.

Inventive Principle:
Principle #25Self-service

2Productivity

If data-limited or data-free detection is implemented, then detection speed and trustworthiness are enhanced, but ability to detect small or subtle triggers deteriorates

Engineering Contradiction:
Improvedetection speedVSAvoidtrigger detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary action by pre-computing and storing the influence matrices of neuron activations during a single forward pass. This preliminary computation enables rapid detection of both large and subtle triggers without requiring multiple data iterations, thus maintaining both speed and precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent transitions from data-space analysis to model-parameter-space analysis. By examining the internal neuron activation patterns and their influences on output predictions, it detects triggers in a different dimensional space that reveals subtle patterns invisible in traditional data-based approaches.

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

3Measurement precision

If multiple adversarial perturbations are generated and neuron activations maximized, then detection accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies partial action by focusing computational effort only on the most informative neuron activations and their influences. Rather than exhaustively analyzing all possible perturbations and activations, it identifies and maximizes the key activations that provide the strongest detection signals, achieving high accuracy with reduced complexity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11394742B2Detecting trojan neural networks
Publication Date: 2022.07.19 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11394742B2 patent drawing
  • US11394742B2 patent drawing
  • US11394742B2 patent drawing

AI summary

One or more computer processors generate a plurality of adversarial perturbations associated with a model, wherein the plurality of adversarial perturbations comprises a universal perturbation and one or more per-sample perturbations. The one or more computer processors identify a plurality of neuron activations associated with the model and the plurality of generated adversarial perturbations. The one or more computer processors maximize the identified plurality of neuron activations. The one or more computer processors determine the model is a Trojan model by leveraging one or more similarities associated with the maximized neuron activations and the generated adversarial perturbations.