FaDec: A Fast Decision-based Attack for Adversarial Machine Learning

Faiq Khalid, Hassan Ali, Muhammad Abdullah Hanif, Semeen Rehman, Rehan Ahmed, Muhammad Shafique

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Due to the excessive use of cloud-based machine learning (ML) services, the smart cyber-physical systems (CPS) are increasingly becoming vulnerable to black-box attacks on their ML modules. Traditionally, the black-box attacks are either transfer attacks requiring model stealing, or score/decision-based gradient estimation attacks requiring a large number of queries. In practical scenarios, especially for cloud-based ML services and timing-constrained CPS use-cases, every query incurs a huge cost, thereby rendering state-of-the-art decision-based attacks ineffective in such settings. Towards this, we propose a novel methodology for automatically generating an extremely fast and imperceptible decision-based attack called FaDec. It follows two main steps: (1) fast estimation of the classification boundary by combining the half-interval search-based algorithm with gradient sign estimation to reduce the number of queries; and (2) adversarial noise optimization to ensure the imperceptibility. For illustration, we evaluate FaDec on the image recognition and traffic sign detection using multiple state-of-the-art DNNs trained on CIFAR-10 and the German Traffic Sign Recognition Benchmarks (GTSRB) datasets. The experimental analysis shows that the proposed FaDec attack is 16x faster compared to the state-of-the-art decision-based attacks, and generates an attack image with better imperceptibility for a much lesser number of iterations, thereby making our attack more powerful in practical scenarios. We open-sourced the complete code and results of our methodology at https://github.com/fklodhi/FaDec.

Original languageEnglish (US)
Title of host publication2020 International Joint Conference on Neural Networks, IJCNN 2020 - Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781728169262
StatePublished - Jul 2020
Event2020 International Joint Conference on Neural Networks, IJCNN 2020 - Virtual, Glasgow, United Kingdom
Duration: Jul 19 2020Jul 24 2020

Publication series

NameProceedings of the International Joint Conference on Neural Networks


Conference2020 International Joint Conference on Neural Networks, IJCNN 2020
Country/TerritoryUnited Kingdom
CityVirtual, Glasgow

ASJC Scopus subject areas

  • Software
  • Artificial Intelligence


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