Modern AI systems, particularly with the rise of big data and deep learning in the last decade, have greatly improved our daily life and at the same time created a long list of controversies. AI systems are often subject to malicious and stealthy subversion that jeopardizes their efficacy. Many of these issues stem from the data-driven nature of machine learning. While big data and deep models significantly boost the accuracy of machine learning models, they also create opportunities for adversaries to tamper with models or extract sensitive data. Malicious data providers can compromise machine learning systems by supplying false data and intermediate computation results. Even a well-trained model can be deceived to misbehave by an adversary who provides carefully designed inputs. Furthermore, curious parties can derive sensitive information of the training data by interacting with a machine-learning model. These adversarial scenarios, known as poisoning attack, adversarial example attack, and inference attack, have demonstrated that security, privacy, and robustness have become more important than ever for AI to gain wider adoption and societal trust.
To address these problems, we proposed the following solutions: (1) FLARE, which detects and mitigates stealthy poisoning attacks by leveraging latent space representations; (2) MANDA, which detects adversarial examples by utilizing evaluations from diverse sources, i.e, model-based prediction and data-based evaluation; (3) FeCo which enhances the robustness of machine learning-based network intrusion detection systems by introducing a novel representation learning method; and (4) DP-FedMeta, which preserves data privacy and improves the privacy-accuracy trade-off in machine learning systems through a novel adaptive clipping mechanism. / Doctor of Philosophy / Over the past few decades, machine learning (ML) has become increasingly popular for enhancing efficiency and effectiveness in data analytics and decision-making. Notable applications include intelligent transportation, smart healthcare, natural language generation, intrusion detection, etc. While machine learning methods are often employed for beneficial purposes, they can also be exploited for malicious intents. Well-trained language models have demonstrated generalizability deficiencies and intrinsic biases; generative ML models used for creating art have been repurposed by fraudsters to produce deepfakes; and facial recognition models trained on big data have been found to leak sensitive information about data owners.
Many of these issues stem from the data-driven nature of machine learning. While big data and deep models significantly improve the accuracy of ML models, they also enable adversaries to corrupt models and infer sensitive data. This leads to various adversarial attacks, such as model poisoning during training, adversarially crafted data in testing, and data inference. It is evident that security, privacy, and robustness have become more important than ever for AI to gain wider adoption and societal trust.
This research focuses on building trustworthy machine-learning systems in adversarial environments from a data perspective. It encompasses two themes: securing ML systems against security or privacy vulnerabilities (security of AI) and using ML as a tool to develop novel security solutions (AI for security). For the first theme, we studied adversarial attack detection in both the training and testing phases and proposed FLARE and MANDA to secure matching learning systems in the two phases, respectively. Additionally, we proposed a privacy-preserving learning system, dpfed, to defend against privacy inference attacks. We achieved a good trade-off between accuracy and privacy by proposing an adaptive data clipping and perturbing method. In the second theme, the research is focused on enhancing the robustness of intrusion detection systems through data representation learning.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/115222 |
| Date | 26 May 2023 |
| Creators | Wang, Ning |
| Contributors | Electrical and Computer Engineering, Lou, Wenjing, Hou, Yiwei Thomas, Freeman, Laura J., Chen, Yimin, Stavrou, Angelos, Wang, Yue J. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf, application/vnd.openxmlformats-officedocument.wordprocessingml.document |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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