activity
20162026
most citedInvisible Backdoor Attacks on Deep Neural Networks via Steganography and Regularization

43 citations · 144 across the 27 of their papers we have counts for

collaborators

27 papers

cs.CR2026

Protecting User Prompts Via Character-Level Differential Privacy

Shashie Dilhara Batan Arachchige, Hassan Jameel Asghar, Benjamin Zi Hao Zhao +2

Large Language Models (LLMs) generate responses based on user prompts. Often, these prompts may contain highly sensitive information, including personally identifiable information…

cs.CV2024

Targeted Therapy in Data Removal: Object Unlearning Based on Scene Graphs

Chenhan Zhang, Benjamin Zi Hao Zhao, Hassan Asghar +1

Users may inadvertently upload personally identifiable information (PII) to Machine Learning as a Service (MLaaS) providers. When users no longer want their PII on these services,…

cs.CR2024

-Privacy for Text and the Curse of Dimensionality

Hassan Jameel Asghar, Robin Carpentier, Benjamin Zi Hao Zhao +1

A widely used method to ensure privacy of unstructured text data is the multidimensional Laplace mechanism for -privacy, which is a relaxation of differential privacy for metr…

cs.CR2024

Preempting Text Sanitization Utility in Resource-Constrained Privacy-Preserving LLM Interactions

Robin Carpentier, Benjamin Zi Hao Zhao, Hassan Jameel Asghar +1

Interactions with online Large Language Models raise privacy issues where providers can gather sensitive information about users and their companies from the prompts. While textual…

cs.SI2024★ 3 cited

GPTs Window Shopping: An analysis of the Landscape of Custom ChatGPT Models

Benjamin Zi Hao Zhao, Muhammad Ikram, Mohamed Ali Kaafar

OpenAI's ChatGPT initiated a wave of technical iterations in the space of Large Language Models (LLMs) by demonstrating the capability and disruptive power of LLMs. OpenAI has prom…

cs.CY2024★ 2 cited

On mission Twitter Profiles: A Study of Selective Toxic Behavior

Hina Qayyum, Muhammad Ikram, Benjamin Zi Hao Zhao +3

The argument for persistent social media influence campaigns, often funded by malicious entities, is gaining traction. These entities utilize instrumented profiles to disseminate d…

cs.SI2024★ 2 cited

Exploring the Distinctive Tweeting Patterns of Toxic Twitter Users

Hina Qayyum, Muhammad Ikram, Benjamin Zi Hao Zhao +3

In the pursuit of bolstering user safety, social media platforms deploy active moderation strategies, including content removal and user suspension. These measures target users eng…

cs.CL2023★ 1 cited

Those Aren't Your Memories, They're Somebody Else's: Seeding Misinformation in Chat Bot Memories

Conor Atkins, Benjamin Zi Hao Zhao, Hassan Jameel Asghar +2

One of the new developments in chit-chat bots is a long-term memory mechanism that remembers information from past conversations for increasing engagement and consistency of respon…

cs.SI2023★ 12 cited

A longitudinal study of the top 1% toxic Twitter profiles

Hina Qayyum, Benjamin Zi Hao Zhao, Ian D. Wood +3

Toxicity is endemic to online social networks including Twitter. It follows a Pareto like distribution where most of the toxicity is generated by a very small number of profiles an…

cs.HC2022

DDoD: Dual Denial of Decision Attacks on Human-AI Teams

Benjamin Tag, Niels van Berkel, Sunny Verma +5

Artificial Intelligence (AI) systems have been increasingly used to make decision-making processes faster, more accurate, and more efficient. However, such systems are also at cons…

cs.CR2022★ 2 cited

Use of Cryptography in Malware Obfuscation

Hassan Jameel Asghar, Benjamin Zi Hao Zhao, Muhammad Ikram +4

Malware authors often use cryptographic tools such as XOR encryption and block ciphers like AES to obfuscate part of the malware to evade detection. Use of cryptography may give th…

cs.CR2022★ 1 cited

Unintended Memorization and Timing Attacks in Named Entity Recognition Models

Rana Salal Ali, Benjamin Zi Hao Zhao, Hassan Jameel Asghar +3

Named entity recognition models (NER), are widely used for identifying named entities (e.g., individuals, locations, and other information) in text documents. Machine learning base…

cs.SI2022

A deep dive into the consistently toxic 1% of Twitter

Hina Qayyum, Benjamin Zi Hao Zhao, Ian D. Wood +3

Misbehavior in online social networks (OSN) is an ever-growing phenomenon. The research to date tends to focus on the deployment of machine learning to identify and classify types…

cs.LG2021★ 2 cited

MANDERA: Malicious Node Detection in Federated Learning via Ranking

Wanchuang Zhu, Benjamin Zi Hao Zhao, Simon Luo +2

Byzantine attacks hinder the deployment of federated learning algorithms. Although we know that the benign gradients and Byzantine attacked gradients are distributed differently, t…

cs.CL2021★ 5 cited

Hidden Backdoors in Human-Centric Language Models

Shaofeng Li, Hui Liu, Tian Dong +4

Natural language processing (NLP) systems have been proven to be vulnerable to backdoor attacks, whereby hidden features (backdoors) are trained into a language model and may only…

cs.LG2021

On the (In)Feasibility of Attribute Inference Attacks on Machine Learning Models

Benjamin Zi Hao Zhao, Aviral Agrawal, Catisha Coburn +5

With an increase in low-cost machine learning APIs, advanced machine learning models may be trained on private datasets and monetized by providing them as a service. However, priva…

cs.CR2021

Oriole: Thwarting Privacy against Trustworthy Deep Learning Models

Liuqiao Chen, Hu Wang, Benjamin Zi Hao Zhao +2

Deep Neural Networks have achieved unprecedented success in the field of face recognition such that any individual can crawl the data of others from the Internet without their expl…

cs.CR2020★ 27 cited

Not one but many Tradeoffs: Privacy Vs. Utility in Differentially Private Machine Learning

Benjamin Zi Hao Zhao, Mohamed Ali Kaafar, Nicolas Kourtellis

Data holders are increasingly seeking to protect their user's privacy, whilst still maximizing their ability to produce machine models with high quality predictions. In this work,…

cs.CR2020

Exploiting Behavioral Side-Channels in Observation Resilient Cognitive Authentication Schemes

Benjamin Zi Hao Zhao, Hassan Jameel Asghar, Mohamed Ali Kaafar +2

Observation Resilient Authentication Schemes (ORAS) are a class of shared secret challenge-response identification schemes where a user mentally computes the response via a cogniti…

cs.CR2020★ 7 cited

Deep Learning Backdoors

Shaofeng Li, Shiqing Ma, Minhui Xue +1

Intuitively, a backdoor attack against Deep Neural Networks (DNNs) is to inject hidden malicious behaviors into DNNs such that the backdoor model behaves legitimately for benign in…

cs.CR2020★ 1 cited

With Great Dispersion Comes Greater Resilience: Efficient Poisoning Attacks and Defenses for Linear Regression Models

Jialin Wen, Benjamin Zi Hao Zhao, Minhui Xue +2

With the rise of third parties in the machine learning pipeline, the service provider in "Machine Learning as a Service" (MLaaS), or external data contributors in online learning,…

cs.CR2020★ 25 cited

On the Resilience of Biometric Authentication Systems against Random Inputs

Benjamin Zi Hao Zhao, Hassan Jameel Asghar, Mohamed Ali Kaafar

We assess the security of machine learning based biometric authentication systems against an attacker who submits uniform random inputs, either as feature vectors or raw inputs, in…

cs.CR2019★ 43 cited

Invisible Backdoor Attacks on Deep Neural Networks via Steganography and Regularization

Shaofeng Li, Minhui Xue, Benjamin Zi Hao Zhao +2

Deep neural networks (DNNs) have been proven vulnerable to backdoor attacks, where hidden features (patterns) trained to a normal model, which is only activated by some specific in…

cs.CR2019★ 6 cited

On Inferring Training Data Attributes in Machine Learning Models

Benjamin Zi Hao Zhao, Hassan Jameel Asghar, Raghav Bhaskar +1

A number of recent works have demonstrated that API access to machine learning models leaks information about the dataset records used to train the models. Further, the work of \ci…