arXiv subjects

Ayse Unsal

Publications and source records attributed to Ayse Unsal.

5 recordsLinked to original sources

arXiv2023

Information-Theoretic Approaches to Differential Privacy

This tutorial studies relationships between differential privacy and various information-theoretic measures by using several selective articles. In particular, we present how these connections can provide new interpretations for the privacy guarantee in systems that deploy differential privacy in an information-theoretic framework. To this end, the tutorial provides an extensive summary on the existing literature that makes use of information-theoretic measures and tools such as mutual information, min-entropy, Kullback-Leibler divergence and rate-distortion function for quantification and characterization of differential privacy in various settings.

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arXiv2022

Adversarial Classification under Gaussian Mechanism: Calibrating the Attack to Sensitivity

This work studies anomaly detection under differential privacy (DP) with Gaussian perturbation using both statistical and information-theoretic tools. In our setting, the adversary aims to modify the content of a statistical dataset by inserting additional data without being detected by using the DP guarantee to her own benefit. To this end, we characterize information-theoretic and statistical thresholds for the first and second-order statistics of the adversary's attack, which balances the privacy budget and the impact of the attack in order to remain undetected. Additionally, we introduce a new privacy metric based on Chernoff information for classifying adversaries under differential privacy as a stronger alternative to $(ε, δ)-$ and Kullback-Leibler DP for the Gaussian mechanism. Analytical results are supported by numerical evaluations.

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arXiv2021

On the Distribution of the Weighted Sum of Chi-Squared Variables

This paper presents the probability distribution function (p.d.f.) and cumulative distribution function (c.d.f.) of the weighted sum of central independent chi-squared random variables with non-zero weighs based on a method using moment generating functions. To obtain the p.d.f. and c.d.f. of such a function, we first derive the moment generating function of this weighted sum using the partial fractions decomposition or the residue method. The results cover the sum of two and three weighted chi-squared random variables, which can easily be adapted to more general cases.

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arXiv2018

Fundamental Limits of Caching in Heterogeneous Networks with Uncoded Prefetching

The work explores the fundamental limits of coded caching in heterogeneous networks where multiple ($N_0$) senders/antennas, serve different users which are associated (linked) to shared caches, where each such cache helps an arbitrary number of users. Under the assumption of uncoded cache placement, the work derives the exact optimal worst-case delay and DoF, for a broad range of user-to-cache association profiles where each such profile describes how many users are helped by each cache. This is achieved by presenting an information-theoretic converse based on index coding that succinctly captures the impact of the user-to-cache association, as well as by presenting a coded caching scheme that optimally adapts to the association profile by exploiting the benefits of encoding across users that share the same cache. The work reveals a powerful interplay between shared caches and multiple senders/antennas, where we can now draw the striking conclusion that, as long as each cache serves at least $N_0$ users, adding a single degree of cache-redundancy can yield a DoF increase equal to $N_0$, while at the same time --- irrespective of the profile --- going from 1 to $N_0$ antennas reduces the delivery time by a factor of $N_0$. Finally some conclusions are also drawn for the related problem of coded caching with multiple file requests.

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arXiv2016

Converse Bounds on Modulation-Estimation Performance for the Gaussian Multiple-Access Channel

This paper focuses on the problem of separately modulating and jointly estimating two independent continuous-valued parameters sent over a Gaussian multiple-access channel (MAC) under the mean square error (MSE) criterion. To this end, we first improve an existing lower bound on the MSE that is obtained using the parameter modulation-estimation techniques for the single-user additive white Gaussian noise (AWGN) channel. As for the main contribution of this work, this improved modulation-estimation analysis is generalized to the model of the two-user Gaussian MAC, which will likely become an important mathematical framework for the analysis of remote sensing problems in wireless networks. We present outer bounds to the achievable region in the plane of the MSEs of the two user parameters, which provides a trade-off between the MSEs, in addition to the upper bounds on the achievable region of the MSE exponents, namely, the exponential decay rates of these MSEs in the asymptotic regime of long blocks.

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