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Marc Tommasi

15 accepted papers

2025

Analysis of Speech Temporal Dynamics in the Context of Speaker Verification and Voice Anonymization

ICASSP 2025accepted

In this paper, we investigate the impact of speech temporal dynamics in application to automatic speaker verification and speaker voice anonymization tasks. We propose several metrics to perform automatic speaker verification based only on phoneme durations. Experimental results demonstrate that pho…

Cited by 0SourceScholar
2025

Privacy Amplification Through Synthetic Data: Insights from Linear Regression

ICML 2025poster

Synthetic data inherits the differential privacy guarantees of the model used to generate it. Additionally, synthetic data may benefit from privacy amplification when the generative model is kept hidden. While empirical studies suggest this phenomenon, a rigorous theoretical understanding is still l…

Cited by 0SourcePDFScholar
2024

Improved Stability and Generalization Guarantees of the Decentralized SGD Algorithm

ICML 2024poster

This paper presents a new generalization error analysis for Decentralized Stochastic Gradient Descent (D-SGD) based on algorithmic stability. The obtained results overhaul a series of recent works that suggested an increased instability due to decentralization and a detrimental impact of poorly-conn…

Cited by 6SourcePDFScholar
2024

Rényi Pufferfish Privacy: General Additive Noise Mechanisms and Privacy Amplification by Iteration via Shift Reduction Lemmas

ICML 2024poster

Pufferfish privacy is a flexible generalization of differential privacy that allows to model arbitrary secrets and adversary's prior knowledge about the data. Unfortunately, designing general and tractable Pufferfish mechanisms that do not compromise utility is challenging. Furthermore, this framewo…

Cited by 3SourcePDFScholar
2023

Differential Privacy has Bounded Impact on Fairness in Classification

ICML 2023poster

We theoretically study the impact of differential privacy on fairness in classification. We prove that, given a class of models, popular group fairness measures are pointwise Lipschitz-continuous with respect to the parameters of the model. This result is a consequence of a more general statement on…

2023

High-Dimensional Private Empirical Risk Minimization by Greedy Coordinate Descent

AISTATS 2023poster

In this paper, we study differentially private empirical risk minimization (DP-ERM). It has been shown that the worst-case utility of DP-ERM reduces polynomially as the dimension increases. This is a major obstacle to privately learning large machine learning models. In high dimension, it is common…

Cited by 7SourcePDFScholar
2023

Refined Convergence and Topology Learning for Decentralized SGD with Heterogeneous Data

AISTATS 2023poster

One of the key challenges in decentralized and federated learning is to design algorithms that efficiently deal with highly heterogeneous data distributions across agents. In this paper, we revisit the analysis of Decentralized Stochastic Gradient Descent algorithm (D-SGD) under data heterogeneity.…

Cited by 42SourcePDFScholar
2022

Differentially Private Coordinate Descent for Composite Empirical Risk Minimization

ICML 2022spotlight

Machine learning models can leak information about the data used to train them. To mitigate this issue, Differentially Private (DP) variants of optimization algorithms like Stochastic Gradient Descent (DP-SGD) have been designed to trade-off utility for privacy in Empirical Risk Minimization (ERM) p…

Cited by 21SourcePDFScholar
2022

FLamby: Datasets and Benchmarks for Cross-Silo Federated Learning in Realistic Healthcare Settings

NeurIPS 2022accept

Federated Learning (FL) is a novel approach enabling several clients holding sensitive data to collaboratively train machine learning models, without centralizing data. The cross-silo FL setting corresponds to the case of few ($2$--$50$) reliable clients, each holding medium to large datasets, and i…

2022

Privacy Attacks for Automatic Speech Recognition Acoustic Models in A Federated Learning Framework

ICASSP 2022accepted

This paper investigates methods to effectively retrieve speaker information from the personalized speaker adapted neural network acoustic models (AMs) in automatic speech recognition (ASR). This problem is especially important in the context of federated learning of ASR acoustic models where a globa…

Cited by 0SourceScholar
2022

Retrieving Speaker Information from Personalized Acoustic Models for Speech Recognition

ICASSP 2022accepted

The widespread of powerful personal devices capable of collecting voice of their users has opened the opportunity to build speaker adapted speech recognition system (ASR) or to participate to collaborative learning of ASR. In both cases, personalized acoustic models (AM), i.e. fine-tuned AM with spe…

Cited by 0SourceScholar
2020

Evaluating Voice Conversion-Based Privacy Protection against Informed Attackers

ICASSP 2020accepted

Speech data conveys sensitive speaker attributes like identity or accent. With a small amount of found data, such attributes can be inferred and exploited for malicious purposes: voice cloning, spoofing, etc. Anonymization aims to make the data unlinkable, i.e., ensure that no utterance can be linke…

Cited by 0SourceScholar
2020

Fully Decentralized Joint Learning of Personalized Models and Collaboration Graphs

AISTATS 2020poster

We consider the fully decentralized machine learning scenario where many users with personal datasets collaborate to learn models through local peer-to-peer exchanges, without a central coordinator. We propose to train personalized models that leverage a collaboration graph describing the relationsh…

2018

Personalized and Private Peer-to-Peer Machine Learning

AISTATS 2018poster

The rise of connected personal devices together with privacy concerns call for machine learning algorithms capable of leveraging the data of a large number of agents to learn personalized models under strong privacy requirements. In this paper, we introduce an efficient algorithm to address the abov…

Cited by 0SourcePDFScholar
2017

Decentralized Collaborative Learning of Personalized Models over Networks

AISTATS 2017poster

We consider a set of learning agents in a collaborative peer-to-peer network, where each agent learns a personalized model according to its own learning objective. The question addressed in this paper is: how can agents improve upon their locally trained model by communicating with other agents that…

Cited by 288SourcePDFScholar