Preprints


Throttling Web Agents Using Reasoning Gates
 Abhinav Kumar, Jaechul Roh, Ali Naseh, Amir Houmansadr, Eugene Bagdasarian
arXiv:2509.01619, Sep 2025

Network-Level Prompt and Trait Leakage in Local Research Agents
 Hyejun Jeong, Mohammadreze Teymoorianfard, Abhinav Kumar, Amir Houmansadr, Eugene Badasarian
arXiv:2508.20282, Aug 2025

Bob's Confetti: Phonetic Memorization Attacks in Music and Video Generation
 Jaechul Roh, Zachary Novack, Yuefeng Peng, Niloofar Mireshghallah, Taylor Berg-Kirkpatrick, and Amir Houmansadr
arXiv:2507.17937, July 2025

R1dacted: Investigating Local Censorship in DeepSeek's R1 Language Model
  Ali Naseh, Harsh Chaudhari, Jaechul Roh, Mingshi Wu, Alina Oprea, and Amir Houmansadr
arXiv:2505.12625, May 2025

OverThink: Slowdown Attacks on Reasoning LLMs
  Abhinav Kumar, Jaechul Roh, Ali Naseh, Marzena Karpinska, Mohit Iyyer, Amir Houmansadr, Eugene Bagdasarian
arXiv:2502.02542, Feb 2025

CensorLab: A Testbed for Censorship Experimentation [ Project Webpage ]
  Jade Sheffey, and Amir Houmansadr
arXiv:2412.16349, Dec 2024

Data Extraction Attacks in Retrieval-Augmented Generation via Backdoors
  Yuefeng Peng, Junda Wang, Hong Yu, and Amir Houmansadr
arXiv:2411.01705, Nov 2024

MeanSparse: Post-Training Robustness Enhancement Through Mean-Centered Feature Sparsification
  Sajjad Amini, Mohammadreza Teymoorianfard, Shiqing Ma, and Amir Houmansadr
arXiv:2406.05927, June 2024

SoK: Challenges and Opportunities in Federated Unlearning
  Hyejun Jeong, Shiqing Ma, and Amir Houmansadr
arXiv:2403.02437, March 2024

Understanding (Un)Intended Memorization in Text-to-Image Generative Models
  Ali Naseh, Jaechul Roh, and Amir Houmansadr
arXiv:2312.07550, Dec 2023

2026


Exploiting Leaderboards for Large-Scale Distribution of Malicious Models
 Anshuman Suri, Harsh Chaudhari, Yuefeng Peng, Ali Naseh, Amir Houmansadr, and Alina Oprea
IEEE S&P (Oakland) 2026

2025


Multilingual and Multi-Accent Jailbreaking of Audio LLMs
  Jaechul Roh, Virat Shejwalkar, and Amir Houmansadr
COLM 2025

Backdooring Bias (B^2) into Diffusion Models
  Ali Naseh, Jaechul Roh, Eugene Bagdasaryan, and Amir Houmansadr
USENIX Security 2025

Exposing and Circumventing SNI-based QUIC Censorship of the Great Firewall of China [ artifacts ]
  Ali Zohaib, Qiang Zao, Jackson Sippe, Abdulrahman Alaraj, Amir Houmansadr, Zakir Durumeric, Eric Wustrow
USENIX Security 2025
( USENIX Security Honorable Mention! )

I'll Shake Your Hand - What Happens After DNS Poisoning
  Jade Sheffey, Ali Zohaib, Dayeon Kang, Zakir Durumeric, Amir Houmansadr, and Qiang Wu
FOCI 2025

Riddle Me This! Stealthy Membership Inference for Retrieval-Augmented Generation
  Ali Naseh, Yuefeng Peng, Anshuman Suri, Harsh Chaudhari, Alina Oprea, and Amir Houmansadr
ACM CCS 2025

A Wall Behind A Wall: Emerging Regional Censorship in China [ artifacts ]
  Mingshi Wu, Ali Zohaib, Zakir Durumeric, Amir Houmansadr, and Eric Wustrow
IEEE S&P (Oakland) 2025

Large Language Models Cannot Even Recognize Your Name
  Dzung Pham, Peter Kairouz, Niloofar Mireshghallah, Eugene Bagdasarian and Amir Houmansadr
PrivaCI 2025

Towards Anonymous Chatbots with (Un)Trustworthy Browser Proxies
  Dzung Pham, Jade Sheffey, Chau Minh Pham, and Amir Houmansadr
MadWeb 2025

Improving Private Random Forest Prediction using Matrix Representation
  Arisa Tajima, Joie Wu, and Amir Houmansadr
AAAI 2025

Wallbleed: A Memory Disclosure Vulnerability in the Great Firewall of China
  Shencha Fan, Jackson Sippe, Sakamoto San, Jade Sheffey, David Fifield, Amir Houmansadr, Elson Wedwards, and Eric Wustrow
NDSS 2025
( FOCI 2025 Best Practical Paper Award! )

RAIFLE: Reconstruction Attacks on Interaction-based Federated Learning with Active Data Manipulation
  Dzung Pham, Shreyas Kulkarni, and Amir Houmansadr
NDSS 2025

DIFFENCE: Fencing Membership Privacy With Diffusion Models
  Yuefeng Peng, Ali Naseh, and Amir Houmansadr
NDSS 2025

2024

OSLO: One-Shot Label-Only Membership Inference Attacks
  Yuefeng Peng, Jaechul Roh, Subhransu Maji, and Amir Houmansadr
NeurIPS 2024

PostMark: A Robust Blackbox Watermark for Large Language Models
  Yapei Chang, Kalpesh Krishna, Amir Houmansadr, John Wieting, Mohit Iyyer
EMNLP 2024

Iteratively Prompting Multimodal LLMs to Reproduce Natural and AI-Generated Images
  Ali Naseh, Katherine Thai, Mohit Iyyer, and Amir Houmansadr
COLM 2024
( Oral Spotlight Presentation )

Variational Inference in Similarity Spaces: A Bayesian Approach to Personalized Federated Learning
  Pedro H. Barros, Fabricio Murai, Amir Houmansadr, Alejandro C. Frery, and Heitor S. Ramos
NeurIPS BDU 2024

Fake or Compromised? Making Sense of Malicious Clients in Federated Learning [ arxiv ]
  Hamid Mozaffari, Sunav Choudhary, and Amir Houmansadr
ESORICS 2024

The Effect of Alter Ego Accounts on A/B Tests in Social Networks
  Katherine Avery, Amir Houmansadr, and David Jensen
The Web 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 Learning
  Virat 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
( The 2025 Caspar Bowden PET Award Runner Up! )
( 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 Models
  Virat 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 Learning
  Virat 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 Mechanisms
  Virat 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 Packets
  Ramin 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 Analysis
  Milad 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

Information Hiding in Communication Networks: Fundamentals, Mechanisms, Applications, and Countermeasures
  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 Services
  Ali 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)

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 Networking
  Chad 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 Smartphones
  Saman 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 Browsing
  Qiyan 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 Actions
  Casey 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)  
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 Flows
  Amir 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