Publications [Google Scholar|DBLP]
Preprints
Iteratively Prompting Multimodal LLMs to Reproduce Natural and AI-Generated ImagesAli Naseh, Katherine Thai, Mohit Iyyer, and Amir Houmansadr
arXiv:2404.13784, April 2024.
Understanding (Un)Intended Memorization in Text-to-Image Generative Models
Ali Naseh, Jaechul Roh, and Amir Houmansadr
arXiv:2312.07550, Dec 2023.
Fake or Compromised? Making Sense of Malicious Clients in Federated Learning
Hamid Mozaffari, Sunav Choudhary, and Amir Houmansadr
arXiv:2403.06319, Mar 2024.
Diffence: Fencing Membership Privacy With Diffusion Models
Yuefeng Peng, Ali Naseh, and Amir Houmansadr
arXiv:2312.04692, Dec 2023.
RAIFLE: Reconstruction Attacks on Interaction-based Federated Learning with Active Data Manipulation
Dzung Pham, Shreyas Kulkarni, and Amir Houmansadr
arXiv:2310.19163, Oct 2023.
2024
The Effect of Alter Ego Accounts on A/B Tests in Social NetworksKatherine Avery, Amir Houmansad, and David Jensen
The Web (short paper) 2024
Memory Triggers: Unveiling Memorization in Text-To-Image Generative Models through Word-Level Duplication
Ali Naseh, Jaechul Roh, and Amir Houmansadr
PPAI 2024
Optimal Obfuscation to Protect Client Privacy in Federated Learning
Bo Guan, Shuangqing Wei, Amir Houmansadr, Hossein Pishro-Nik, and Dennis Goeckel
CISS 2024
Fingerprinting Obfuscated Proxy Traffic with Encapsulated TLS Handshakes
Diwen Xue, Michalis Kallitsis, Amir Houmansadr, and Roya Ensafi
USENIX Security 2024
2023
The Perils of Learning From Unlabeled Data: Backdoor Attacks on Semi-supervised LearningVirat Shejwalkar, Lingjuan Lyu, and Amir Houmansadr
ICCV 2023
Location Privacy Protection for UAVs in Package Delivery and IoT Data Collection
Saeede Enayati, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
IEEE Internet of Things Journal 2023
Stealing the Decoding Algorithms of Language Models [arXiv]
Ali Naseh, Kalpesh Krishna, Mohit Iyyer, Amir Houmansadr
ACM CCS 2023
(Distinguished Paper Award!)
Realistic Website Fingerprinting By Augmenting Network Traces
Alireza Bahramali, Ardavan Bozorgi, and Amir Houmansadr
ACM CCS 2023
Investigating Traffic Analysis Attacks on Apple iCloud Private Relay
Ali Zohaib, Jade Sheffey, and Amir Houmansadr
AsiaCCS 2023
Effectively Using Public Data in Privacy Preserving Machine Learning
Milad Nasr, Saeed Mahloujifar, Xinyu Tang, Prateek Mittal, and Amir Houmansadr
ICML 2023
On the Pitfalls of Security Evaluation of Robust Federated Learning
Momin Khan, Virat Shejwalkar, Amir Houmansadr, and Fatima Anwar
DLSP 2023
Where Have All the Paragraphs Gone? Detecting and Exposing Censorship in Chinese Translation
Mizhang Streisand, Eric Wustrow, and Amir Houmansadr
FOCI 2023
Automated Detection of IPv6 Privacy Leakage in Home Networks
Ali Zohaib, and Amir Houmansadr
FOCI 2023
How the Great Firewall of China Detects and Blocks Fully Encrypted Traffic
Mingshi Wu, Jackson Sippe, Danesh Sivakumar, Jack Burg, Peter Anderson, Xiaokang Wang, Kevin Bock, Amir Houmansadr, Dave Levin, Eric Wustrow
USENIX Security 2023
(2024 Applied Networking Research Prize (ANRP)!)
(First Place at CSAW 2023 Applied Research Competition!)
(FOCI 2023 Best Practical Paper Award!)
Every Vote Counts: Ranking-Based Training of Federated Learning to Resist Poisoning Attacks [arXiv]
Hamid Mozaffari, Virat Shejwalkar, and Amir Houmansadr
USENIX Security 2023
2022
I Still Know What You Did Last Summer: Inferring Sensitive User Activities on Messaging Applications Through Traffic Analysis [copy]Ardavan Bozorgi, Alireza Bahramali, Fateme Rezaei, Amirhossein Ghafari, Amir Houmansadr, Ramin Soltani, Dennis Goeckel, and Don Towsley
IEEE Transactions on Dependable and Secure Computing 2022
Security Analysis of SplitFed Learning
Momin Ahmad Khan, Virat Shejwalkar, Amir Houmansadr, and Fatima M. Anwar
AIChallengeIoT 2022
Superstring-Based Sequence Obfuscation to Thwart Pattern Matching Attacks
Bo Guan, Nazanin Takbiri, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
IEEE Internet of Things Journal 2022
Robust Indistinguishability
Amir Houmansadr, Monica Moniot, and Adam O'Neill
FCS 2022
Equity and Equality in Fair Federated Learning
Hamid Mozaffari, and Amir Houmansadr
ICML-RDMDE 2022
Improving Differentially Private Deep Learning using Adaptive Origin Selection
Milad Nasr, Saeed Mahloujifar, Xinyu Tang, Virat Shejwalkar, Amir Houmansadr, Prateek Mittal
TPDP 2022
Machine Learning with Differentially Private Labels: Mechanisms and Frameworks
Xinyu Tang, Milad Nasr, Saeed Mahloujifar, Virat Shejwalkar, Liwei Song, Amir Houmansadr, and Prateek Mittal
PETS 2022
Privacy-Preserving Path-Planning for UAVs
Saeede Enayati, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
ISNCC 2022
Constrained Obfuscation to Thwart Pattern Matching Attacks
Saeede Enayati, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
ISIT 2022
Robust Federated Learning By Training on Parameter Ranks
Hamid Mozaffari, Virat Shejwalkar, and Amir Houmansadr
FL-AAAI (Oral) 2022
Back to the Drawing Board: A Critical Evaluation of Poisoning Attacks on Production Federated Learning [arXiv] [code]
Virat Shejwalkar, Amir Houmansadr, Peter Kairouz, and Daniel Ramage
IEEE S&P (Oakland) 2022
Mitigating Membership Inference Attacks by Self-Distillation Through a Novel Ensemble Architecture
Xinyu Tang, Saeed Mahloujifar, Liwei Song, Virat Shejwalkar, Milad Nasr, Amir Houmansadr, and Prateek Mittal
USENIX Security 2022
2021
Membership Inference Attacks Against NLP Classification ModelsVirat Shejwalkar, Huseyin A Inan, Amir Houmansadr, and Robert Sim
NeurIPS PriML 2021
A Novel Self-Distillation Architecture to Defeat Membership Inference Attacks
Xinyu Tang, Saeed Mahloujifar, Liwei Song, Virat Shejwalkar, Milad Nasr, Amir Houmansadr, and Prateek Mittal
NeurIPS PriML 2021
Cronus: Robust and Heterogeneous Collaborative Learning with Black-Box Knowledge Transfer
Hongyan Chang, Virat Shejwalkar, Reza Shokri, and Amir Houmansadr
NeurIPS NFFL 2021
FINN: Fingerprinting Network Flows using Neural Networks
Fatemeh Rezaei, and Amir Houmansadr
ACSAC 2021
Robust Adversarial Attacks Against DNN-Based Wireless Communication Systems [arXiv]
Alireza Bahramali, Milad Nasr, Amir Houmansadr, Dennis Goeckel, and Don Towsley
ACM CCS 2021
Defeating DNN-Based Traffic Analysis Systems in Real-Time With Blind Adversarial Perturbations [arXiv]
Milad Nasr, Alireza Bahramali, and Amir Houmansadr
USENIX Security 2021
Manipulating the Byzantine: Optimizing Model Poisoning Attacks and Defenses for Federated Learning [code]
Virat Shejwalkar and Amir Houmansadr
NDSS 2021
Membership Privacy for Machine Learning Models Through Knowledge Transfer [code]
Virat Shejwalkar and Amir Houmansadr
AAAI 2021 (Acceptance rate: 21%)
Asymptotic Privacy Loss due to Time Series Matching of Dependent Users [arXiv]
Nazanin Takbiri, Minting Chen, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
IEEE Communications Letters 2021
2020
Towards Optimized Model Poisoning Attacks Against Federated LearningVirat Shejwalkar and Amir Houmansadr
SpicyFL 2020
Machine Learning with Membership Privacy via Knowledge Transfer
Virat Shejwalkar and Amir Houmansadr
PPML 2020
How China Detects and Blocks Shadowsocks
Alice, Bob, Carol, Jan Beznazwy, and Amir Houmansadr
IMC 2020 (Acceptance rate: 25%)
(IMC’20 Best Paper Award Runner-Up!)
Blog Post Talk
The Bitcoin Hunter: Detecting Bitcoin Traffic Over Encrypted Channels
Fatemeh Rezaei, Shahrzad Naseri, Amir Houmansadr, and Ittay Eyal
SecureComm 2020
Triplet Censors: Demystifying Great Firewall’s DNS Censorship Behavior
Anonymous, Arian Akhavan Niaki, Nguyen Phong Hoang, Phillipa Gill, and Amir Houmansadr
USENIX FOCI 2020
Leveraging Prior Knowledge Asymmetries in the Design of Location Privacy-Preserving Mechanisms
Nazanin Takbiri, Virat Shejwalkar, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
IEEE Wireless Communications Letters 2020
Sequence Obfuscation to Thwart Pattern Matching Attacks
Bo Guan, Nazanin Takbiri, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
ISIT 2020
Fundamental Limits of Covert Packet Insertion
Ramin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
IEEE Transactions on Communications 2020
Privacy of Dependent Users Against Statistical Matching
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
IEEE Transactions on Information Theory 2020
Heterogeneous Private Information Retrieval
Hamid Mozaffari and Amir Houmansadr
NDSS 2020 (Acceptance rate: 18%)
Practical Traffic Analysis Attacks on Secure Messaging Applications
Alireza Bahramali, Amir Houmansadr, Ramin Soltani, Dennis Goeckel, and Don Towsley
NDSS 2020 (Acceptance rate: 18%)
MassBrowser: Unblocking the Censored Web for the Masses, by the Masses
Milad Nasr, Hadi Zolfaghari, Amir Houmansadr, and Amirhossein Ghafari
NDSS 2020 (Acceptance rate: 18%)
Project Webpage, Technical Report
Fundamental Limits of Invisible Flow Fingerprinting
Ramin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
IEEE Transactions on Information Forensics and Security 2020
2019
Revisiting Utility Metrics for Location Privacy-Preserving MechanismsVirat Shejwalkar, Amir Houmansadr, Hossein Pishro-Nik, and Dennis Goeckel
ACSAC 2019
Blocking-Resilient Communications in Information-Centric Networks using Router Redirection
Hamid Mozaffari, Amir Houmansadr, and Arun Venkataramani
ICEC 2019
Generalizable Deep Learning with Differential Privacy; Using Gradient Compression and De-noising
Milad Nasr, Reza Shokri, and Amir Houmansadr
TPDP 2019
On the Importance of Encrypted-SNI (ESNI) to Censorship Circumvention
Zimo Chai, Amirhossein Ghafari, and Amir Houmansadr
USENIX FOCI 2019
Asymptotic Limits of Privacy in Bayesian Time Series Matching
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
CISS 2019
Comprehensive Privacy Analysis of Deep Learning: Stand-alone and Federated Learning under Passive and Active White-box Inference Attacks
Milad Nasr, Reza Shokri, and Amir Houmansadr
IEEE S&P (Oakland) 2019 (acceptance rate: 12%)
Asymptotic Loss in Privacy due to Dependency in Gaussian Traces
Nazanin Takbiri, Ramin Soltani, Dennis Goeckel, Amir Houmansadr, and Hossein Pishro-Nik
IEEE WCNC 2019
Enemy At the Gateways: Censorship-Resilient Proxy Distribution Using Game Theory
Milad Nasr, Sadegh Farhang, Amir Houmansadr, and Jens Grossklags
NDSS 2019 (Acceptance rate: 17% = 89/521)
Matching Anonymized and Obfuscated Time Series to Users' Profiles
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
IEEE Transactions on Information Theory 65(2): 724-741, 2019
2018
Fundamental Limits of Covert Bit Insertion in PacketsRamin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
Allerton 2018
DeepCorr: Strong Flow Correlation Attacks on Tor Using Deep Learning
Milad Nasr, Alireza Bahramali, and Amir Houmansadr
ACM CCS 2018 (Acceptance rate: 16.6% = 134/809)
(CSAW’19 Applied Research Competition Finalist!)
Machine Learning with Membership Privacy using Adversarial Regularization
Milad Nasr, Reza Shokri, and Amir Houmansadr
ACM CCS 2018 (Acceptance rate: 16.6% = 134/809)
Belief-Space Planning for Automated Malware Defense
Justin Svegliato, Sam Witty, Amir Houmansadr, and Shlomo Zilberstein
AI4IoT 2018
Main-Memory Requirements of Big Data Applications on Commodity Server Platform
Hosein Mohammadi Makrani, Setareh Rafatirad, Amir Houmansadr, and Houman Homayoun
DBDM 2018
Privacy against Statistical Matching: Inter-User Correlation
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
ISIT 2018
2017
Compressive Traffic Analysis: A New Paradigm for Scalable Traffic AnalysisMilad Nasr, Amir Houmansadr, and Arya Mazumdar
ACM CCS 2017
The Waterfall of Liberty: Decoy Routing Circumvention that Resists Routing Attacks
Milad Nasr, Hadi Zolfaghari, and Amir Houmansadr
ACM CCS 2017
Graphene: A New Protocol for Block Propagation Using Set Reconciliation [arXiv version]
Pinar Ozisik, Gavin Andresen, George Bissias, Amir Houmansadr and Brian N. Levine
CBT 2017
Towards Provably Invisible Network Flow Fingerprints
Ramin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
Asilomar 2017
TagIt: Tagging Network Flows using Blind Fingerprints
Fatemeh Rezaei and Amir Houmansadr
PETS 2017
Achieving Perfect Location Privacy in Wireless Devices Using Anonymization
Zarrin Montazeri, Amir Houmansadr, and Hossein Pishro-Nik
IEEE Transactions on Information Forensics and Security 2017
Limits of Location Privacy under Anonymization and Obfuscation
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
ISIT 2017
Fundamental Limits of Location Privacy Using Anonymization
Nazanin Takbiri, Amir Houmansadr, Dennis Goeckel, and Hossein Pishro-Nik
CISS 2017
SWEET: Serving the Web by Exploiting Email Tunnels
Amir Houmansadr, Wenxuan Zhou, Matthew Caesar, and Nikita Borisov
IEEE/ACM Transactions on Networking, January 2017
2016
Wojciech Mazurczyk, Steffen Wendzel, Sebastian Zander, Amir Houmansadr, and Krzysztof Szczypiorski
Wiley-IEEE Press, February 2016
(Available on Amazon)
Covert Communications on Renewal Packet Channels [arXiv version]
Ramin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
Allerton 2016
GAME OF DECOYS: Optimal Decoy Routing Through Game Theory
Milad Nasr and Amir Houmansadr
ACM CCS 2016 (acceptance rate: 16% = 137/831)
Practical Censorship Evasion Leveraging Content Delivery Networks
Hadi Zolfaghari and Amir Houmansadr
ACM CCS 2016 (acceptance rate: 16% = 137/831)
Achieving Perfect Location Privacy in Markov Models Using Anonymization
Zarrin Montazeri, Amir Houmansadr, and Hossein Pishro-Nik
ISITA 2016
CovertCast: Using Live Streaming to Evade Internet Censorship
Richard McPherson, Amir Houmansadr, and Vitaly Shmatikov
PETS 2016
Defining Perfect Location Privacy Using Anonymization
Zarrin Montazeri, Amir Houmansadr, and Hossein Pishro-Nik
CISS 2016
2015
Know Your Achilles' Heel: Automatic Detection Of Network Critical ServicesAli Zand, Amir Houmansadr, Giovanni Vigna, Richard Kemmerer, and Christopher Kruegel
ACSAC 2015
CacheBrowser: Bypassing Chinese Censorship without Proxies Using Cached Content
John Holowczak and Amir Houmansadr
ACM CCS 2015 (acceptance rate: 19.8% = 128/646)
(Media: MIT Technology Review)
Covert Communications on Poisson Packet Channels [arXiv version]
Ramin Soltani, Dennis Goeckel, Don Towsley, and Amir Houmansadr
Allerton 2015
2014
CloudTransport: Using Cloud Storage for Censorship-Resistant NetworkingChad Brubaker, Amir Houmansadr, and Vitaly Shmatikov
PETS 2014 (acceptance rate: 18.6% = 16/86)
No Direction Home: The True Cost of Routing Around Decoys
Amir Houmansadr, Edmund L Wong, and Vitaly Shmatikov
NDSS 2014 (acceptance rate: 18.6%)
Non-Blind Watermarking of Network Flows
Amir Houmansadr, Negar Kiyavash, and Nikita Borisov
IEEE/ACM Transactions on Networking, August 2014
2013
Secloud: A Cloud-based Comprehensive and Lightweight Security Solution for SmartphonesSaman A. Zonouz, Amir Houmansadr, Robin Berthier, Nikita Borisov, and William Sanders
Journal of Computers & Security, September 2013
The Need for Flow Fingerprints to Link Correlated Network Flows
Amir Houmansadr and Nikita Borisov
PETS 2013 (acceptance rate: 18% = 13/69)
SWEET: Serving the Web by Exploiting Email Tunnels
Wenxuan Zhou, Amir Houmansadr, Matthew Caesar, and Nikita Borisov
HotPETs 2013
The Parrot is Dead: Observing Unobservable Network Communications
Amir Houmansadr, Chad Brubaker, and Vitaly Shmatikov
IEEE S&P (Oakland) 2013 (acceptance rate: 12% = 38/315)
(Best Practical Paper Award of the IEEE S&P)
BotMosaic: Collaborative Network Watermark for the Detection of IRC-Based Botnets
Amir Houmansadr and Nikita Borisov
Journal of Systems and Software, March 2013
I Want My Voice to Be Heard: IP Over Voice-over-IP for Unobservable Censorship Circumvention
Amir Houmansadr, Thomas Riedl, Nikita Borisov, and Andrew Singer
NDSS 2013 (acceptance rate: 18.8% = 47/250)
2012
CensorSpoofer: Asymmetric Communication using IP Spoofing for Censorship-Resistant Web BrowsingQiyan Wang, Xun Gong, Giang Nguyen, Amir Houmansadr, and Nikita Borisov
CCS 2012 (acceptance rate: 18.9% = 80/423)
Multi-Flow Attacks Against Network Flow Watermarks: Analysis and Countermeasures
Negar Kiyavash, Amir Houmansadr, and Nikita Borisov
Computing Research Repository arXiv, arXiv:1203.1390v1, 2012.
Design, Analysis, and Implementation of Effective Network flow Watermarking Schemes
Amir Houmansadr Ph.D. Thesis, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, August 2012
EliMet: Security Metric Elicitation in Power Grid Critical Infrastructures by Observing System Administrators' Responsive Behavior
Saman A. Zonouz, Amir Houmansadr, and Parisa Haghani
DSN 2012 (acceptance rate: 17.3%)
2011
Nexat: A History-based Approach to Predict Attacker ActionsCasey Cipriano, Ali Zand, Amir Houmansadr, Christopher Kruegel, and Giovanni Vigna
ACSAC 2011 (acceptance rate: 20% = 39/195)
Cirripede: Circumvention Infrastructure using Router Redirection with Plausible Deniability
Amir Houmansadr, Giang T. K. Nguyen, Matthew Caesar, and Nikita Borisov
CCS 2011 (acceptance rate: 14% = 60/429)
A Cloud-based Intrusion Detection and Response System for Mobile Phones
Amir Houmansadr, Saman A. Zonouz, and Robin Berthier
WRAITS 2011
CoCo: Coding-Based Covert Timing Channels for Network Flows
Amir Houmansadr and Nikita Borisov
IH 2011 (acceptance rate: 32% = 22/68)
Stegobot: A Covert Social Network Botnet
Shishir Nagaraja, Amir Houmansadr, Pragya Agarwal, Vijit Kumar, Pratch Piyawongwisal, and Nikita Borisov
IH 2011 (acceptance rate: 32% = 22/68)
Media: [New Scientist] [msnbc] [Times of India] [Security News Daily] [Think Digit] [Criminal Wisdom] [LaptopMag] [SiliconIndia] [CSL] [NetworkSolutionTips] [...]
Towards Improving Network Flow Watermarking Using the Repeat-Accumulate Codes
Amir Houmansadr and Nikita Borisov
ICASSP 2011
SWIRL: A Scalable Watermark to Detect Correlated Network Flows
Amir Houmansadr and Nikita Borisov
NDSS 2011 (acceptance rate: 20% = 28/139)
Before 2010
Multi-Flow Attack Resistant Watermarks for Network FlowsAmir Houmansadr, Negar Kiyavash, and Nikita Borisov
ICASSP 2009
RAINBOW: A Robust And Invisible Non-Blind Watermark for Network Flows
Amir Houmansadr, Negar Kiyavash, and Nikita Borisov
NDSS 2009 (acceptance rate: 11.7% = 20/171)
Multi-flow Attacks Against Network Flow Watermarking Schemes
Negar Kiyavash, Amir Houmansadr, and Nikita Borisov
USENIX Security 2008 (acceptance rate: 15.9% = 27/170)
A Collusion-Resistant Video Watermarking Scheme
Amir Houmansadr and Shahrokh Ghaemmaghami
IH 2006
Robust Content-based Video Watermarking Exploiting Motion Entropy Masking Effect
Amir Houmansadr, Hamed Pirsiavash, and Shahrokh Ghaemmaghami
SIGMAP 2006
A Novel Video Watermarking Method Using Visual Cryptography
Amir Houmansadr and Shahrokh Ghaemmaghami
ICEIS 2006
Entropy Video Watermarking Using HVS Models
Amir Houmansadr
M.Sc. Thesis, Electrical Engineering Department, Sharif University of Technology, 2005
Robustness Enhancement of Content Based Watermarks using Entropy Masking Effect
Amir Houmansadr and Shahrokh Ghaemmaghami
IWDW 2005
A Digital Image Watermarking Scheme Based on Visual Secret Sharing
Amir Houmansadr and Shahrokh Ghaemmaghami
IST 2005
Synchronization Methods in PSK Modulation Amir Houmansadr
B.Sc. Thesis, Electrical Engineering Department, Sharif University of Technology, 2003
