Privacy-Preserving Machine Learning via Knowledge Distillation

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Solution Overview

Problem

In business-to-business machine learning projects, data privacy concerns arise when multiple parties are involved, as participants may not trust sharing their private data, hindering the training of machine learning models, especially for hospitals that lack computation resources.

Innovation Solution

A private and interpretable machine learning framework that uses knowledge distillation with perturbation to protect data privacy by transferring perturbed knowledge from teacher modules to student modules, reducing the risk of data exposure through batch-by-batch queries and differential privacy techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If private data is shared between multiple parties to train machine learning models, then model training capability is improved, but data privacy security deteriorates

Engineering Contradiction:
Improvemodel training capabilityVSAvoiddata privacy security
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a trusted third party (the server) as an intermediary that coordinates the machine learning training process without accessing the raw private data. The server aggregates gradients from multiple parties and performs federated averaging to update model parameters, enabling collaborative model training while keeping sensitive data localized at each party's premises and preventing direct data exposure between participants.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the data and computation across multiple independent parties, where each party maintains its own local data and computes local model updates independently. Only the aggregated gradient information is shared with the server, not the raw data itself. This segmentation allows model training to proceed while preserving data privacy by ensuring that no single party or intermediary can access or expose the full private datasets.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If data is exposed to enable model training, then prediction accuracy is improved, but trust between parties deteriorates

Engineering Contradiction:
Improveprediction accuracyVSAvoidtrust between parties
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The server acts as a neutral intermediary that facilitates model training without compromising party trust. It collects gradients from all parties, performs secure aggregation, and distributes updated parameters back to parties. This intermediary role enables accurate prediction model training while maintaining trust, as each party contributes to the collective model without exposing its private data to others, and the server operates transparently without accessing raw data.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of sharing raw data, the system shares copies of gradient information that encode model update directions without containing actual data. The gradients are computed locally from private data but only the aggregated gradient copies are transmitted to the server. This copying approach allows the model to learn from diverse data sources and improve prediction accuracy while maintaining trust, as the shared information is transformed into abstract update instructions rather than exposed data.

Inventive Principle:
Principle #26Copying

3Productivity

If computation resources are increased to train models, then model performance is improved, but cost deteriorates

Engineering Contradiction:
Improvemodel performanceVSAvoidcomputation resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent merges the computation resources of multiple parties through federated averaging. Each party performs local training computations using its own data and computation capabilities, then the server aggregates these local results to produce a global model update. This merging approach enables high model performance by leveraging the combined computational power and data diversity of all parties, while avoiding the need for any single party to deploy expensive large-scale models independently, thus reducing overall system cost.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS11568306B2Data privacy protected machine learning systems
Publication Date: 2023.01.31 SALESFORCE INC
  • US11568306B2 patent drawing
  • US11568306B2 patent drawing
  • US11568306B2 patent drawing

AI summary

Approaches for private and interpretable machine learning systems include a system for processing a query. The system includes one or more teacher modules for receiving a query and generating a respective output, one or more privacy sanitization modules for privacy sanitizing the respective output of each of the one or more teacher modules, and a student module for receiving a query and the privacy sanitized respective output of each of the one or more teacher modules and generating a result. Each of the one or more teacher modules is trained using a respective private data set. The student module is trained using a public data set. In some embodiments, human understandable interpretations of an output from the student module is provided to a model user.