Distributed Privacy-Preserving Prediction

Another day, another paper, this time by my postdoc Lingjuan Lyu and a few collaborators. Here’s the abstract: In privacy-preserving machine learning, individual parties are reluctant to share their sensitive training data due to privacy concerns. Even the trained model parameters or prediction can pose serious privacy leakage. To address these problems, we demonstrate a … More Distributed Privacy-Preserving Prediction

Accurate and Efficient Privacy-Preserving String Matching

A few ANU colleagues and I have just completed a paper on a suffix-tree-based algorithm for computing the longest common substring of two strings in a privacy-preserving manner. Here’s the abstract: The task of calculating similarities between strings held by different organizations without revealing these strings is an increasingly important problem in areas such as … More Accurate and Efficient Privacy-Preserving String Matching

Linking Integer Records: The Simplest Case of PPRL

Privacy-Preserving Record Linkage (PPRL) is one of those problems that still doesn’t have a solid and widely accepted mathematical definition, perhaps because the problem of Record Linkage itself, especially the kind that doesn’t reduce to supervised learning through an abundance of labelled matches, still doesn’t have a solid mathematical definition despite thousands of papers published … More Linking Integer Records: The Simplest Case of PPRL

Useful Technical Tutorials on Fully Homomorphic Encryption

I have gone through quite a few articles over the last 12 months in my attempt to get a proper understanding of fully homomorphic encryption (FHE) schemes. The process was somewhat frustrating because most of the articles are either too basic, giving just very high-level intuitions, or too deep, assuming too much background on the … More Useful Technical Tutorials on Fully Homomorphic Encryption

Hardening Bloom Filters using Paillier Encryption

Bloom FiltersĀ is a popular technique for privacy-preserving record linkage. However, recent work by Christen et al [1] and others have shown that Bloom Filters (BF) are susceptible to different forms of frequency attack. There are many ideas on hardening BF to protect against frequency attacks, and one idea we will explore in this blog article … More Hardening Bloom Filters using Paillier Encryption

Multiplication and Comparison Operations in Paillier

As is well known, the Paillier encryption system supports addition of two encrypted numbers and the scalar multiplication of a constant and an encrypted number. I learned recently one can compare two encrypted numbers and multiply two encrypted numbers in Paillier by making a trip to the private key holder. Let’s first look at comparison. … More Multiplication and Comparison Operations in Paillier