Title
Adversarial Attacks On Linear Contextual Bandits
Abstract
Contextual bandit algorithms are applied in a wide range of domains, from advertising to recommender systems, from clinical trials to education. In many of these domains, malicious agents may have incentives to force a bandit algorithm into a desired behavior. For instance, an unscrupulous ad publisher may try to increase their own revenue at the expense of the advertisers; a seller may want to increase the exposure of their products, or thwart a competitor's advertising campaign. In this paper, we study several attack scenarios and show that a malicious agent can force a linear contextual bandit algorithm to pull any desired arm T - o(T) times over a horizon of T steps, while applying adversarial modifications to either rewards or contexts with a cumulative cost that only grow logarithmically as O(log T). We also investigate the case when a malicious agent is interested in affecting the behavior of the bandit algorithm in a single context (e.g., a specific user). We first provide sufficient conditions for the feasibility of the attack and an efficient algorithm to perform an attack. We empirically validate the proposed approaches in synthetic and real-world datasets.
Year
Venue
DocType
2020
ADVANCES IN NEURAL INFORMATION PROCESSING SYSTEMS (NEURIPS 2020)
Conference
Volume
ISSN
Citations 
33
1049-5258
0
PageRank 
References 
Authors
0.34
0
7
Name
Order
Citations
PageRank
Evrard Garcelon102.70
Baptiste Rozière293.15
Meunier, Laurent322.05
Jean Tarbouriech401.69
Olivier Teytaud579484.86
Alessandro Lazaric651848.19
Matteo Pirotta77818.50