This speaker series is made possible by an anonymous charitable donation in memory of cypherpunks and privacy advocates Len Sassaman, Hugh Daniel, Hal Finney, and Caspar Bowden.
Most of the talks are video recorded, and are viewable on this site or on our YouTube channel.
Upcoming speakers
For All Tomorrow's Survivors: Computer Security in Interpersonal Threat Models
Thomas Ristenpart, University of Toronto
March 24, 2026 1:30pm, in DC 1304 and Zoom
Abstract
Computer security is traditionally about the protection of digital systems from adversaries such as criminals or governments. In this talk, I will explore interpersonal threat models, in which the adversary is a member of the victim's social circles---an intimate partner, family member, or other close acquaintance---and who seeks to cause harm to the victim, not just their technology. Such known-adversary threat models are a widespread and increasingly severe problem, and their study opens up a new frontier for computer security research and practice.
This perspective has emerged from my research and advocacy in the context of interpersonal abuse contexts such as intimate partner violence (IPV) and human trafficking. Our research details the multifaceted and damaging ways in which abusers exploit technology to harass, impersonate, threaten, monitor, intimidate, and otherwise harm their target via spyware, social media, tracking tools, account compromise, and more. To make progress, I take an advocate-scientist approach that blends ongoing evidence-based design and delivery of clinics that directly assist survivors suffering tech abuse; systemic advocacy for new laws and policies; and basic research into how to design technology to improve its security in the face of known-adversary threats. The latter requires understanding and resolving complex tensions between known-adversary and traditional threat models, with result being principled reworkings of some of our most fundamental security tools to increase security and safety for all users.
The talk will include discussion of physical, sexual, and emotional violence.
Bio
Thomas Ristenpart is a professor at the University of Toronto. He has been faculty at Cornell Tech and the department of computer science at Cornell University since May, 2015, and before that spent four and a half years as an assistant professor at the University of Wisconsin-Madison. He completed his PhD at UC San Diego in 2010. His research spans a wide range of computer security topics, with recent focuses including digital privacy and safety in interpersonal violence, anti-abuse mitigations for encrypted messaging systems, improvements to authentication mechanisms including passwords, and topics in applied and theoretical cryptography. His work is routinely featured in the media and has been recognized by numerous distinguished paper awards, three ACM CCS test-of-time awards, one USENIX Security test-of-time awards, an Advocate of New York City award, an NSF CAREER Award, and a Sloan Research Fellowship.
Past speakers
2025-2026
2024-2025
2023-2024
2022-2023
2021-2022
2020-2021
2019-2020
2018-2019
2017-2018
2016-2017
2015-2016
2014-2015
2013-2014
2012-2013
2011-2012
- 19 Jan 2012: Sonia Chiasson, Carleton University
- "The convergence of human factors and computer security"
- 12 Dec 2011: Nadia Heninger, UC San Diego
- "Approximate common divisors via lattices"
- 14 Nov 2011: Eugene Vasserman, Kansas State University
- "Censorship Resistant Overlay Publishing"
- 21 Nov 2011: Vinod Vaikuntanathan, University of Toronto
- "Computing Blindfolded: New Developments in Fully Homomorphic Encryption"
- 24 October 2011: Kevin Bauer, University of Waterloo
- "Improving Security and Performance in Low-Latency Anonymity Networks"
- 7 September 2011: Tamir Tassa, The Open University of Israel
- "Generalized Oblivious Transfer by Secret Sharing"
- 8 August 2011: Ahmad-Reza Sadeghi, Technical University Darmstadt
- "Cloudy and Phony: On the Convergence of Cloud and Smartphone Security"
- 26 July 2011: Jean-Pierre Hubaux, EPFL
- "Two Short Talks about the Security of Web Applications"
- 28 May 2011: Ryan Henry, University of Waterloo
- "Formalizing and Extending Anonymous Blacklisting Systems"
2010-2011 (MITACS Speaker Series on Privacy)
- 1 April 2011: Matthew Wright, University of Texas at Arlington
- "Removing Detectable Statistics from Covert Channels"
- 11 March 2011: Prateek Mittal, University of Illinois, Urbana-Champaign
- "Throughput Fingerprinting-based Traffic Analysis of Low Latency Anonymous Communication"
- 8 Mar 2011: Mohammad Hossein Manshaei, EPFL
- "Game Theory Meets Network Security and Privacy"
- 15 Dec 2010: Femi Olumofin, University of Waterloo
- "Preserving Access Privacy Over Large Databases"
- 10 Dec 2010: Aleksander Essex, University of Waterloo
- "Eperio: Mitigating Technical Complexity in Cryptographic Election Verificaiton"
- 9 Dec 2010: Ryan Henry, University of Waterloo
- "Nymbler: Privacy-enhanced Protection from Abuses of Anonymity"
- 3 Dec 2010: Jeremy Clark, University of Waterloo
- "Selections: An Internet Voting System with Over-the-shoulder Coercion Resistance"
- 1 Dec 2010: Femi Olumofin, University of Waterloo
- "Revisiting the Computational Practicality of Private Information Retrieval"
- 26 Nov 2010: Aleksander Essex, University of Waterloo
- "Hacking Democracy: An Election Fraudster's Tricks of the Trade"
- 12 Nov 2010: Stacey Jeffery, University of Waterloo
- "Dealing with Ghosts: Trading Robustness for Correctness and Privacy in Certain Multiparty Functions, Beyond an Honest Majority"
- 22 October 2010: Kevin Bauer, University of Colorado
- "Toward Improving Tor's Security and Performance"
- 24 September 2010: Alessandro Acquisti, Carnegie Mellon University
- "Privacy, Behavioral Economics, and the Control Paradox"
- 9 Sep 2010: Christian Henrich, Karlsruhe Institute of Technology
- "Bingo Voting — Verifiable Voting Scheme Based on a Trusted Random Number Generator"
- 26 July 2010: Maura Paterson, Birkbeck, University of London
- "Distinct-difference configurations: multihop paths and key predistribution in sensor networks"
- 14 July 2010: Atefeh Mashatan, EPFL
- "A Message Recognition Protocol Based on Standard Assumptions"
- 12 July 2010: Tara Whalen, Office of the Privacy Commissioner of Canada
- "Technology and Privacy: A Short Tour through an Emerging Landscape"
A video of the talk is available.
- 8 July 2010: Greg Zaverucha, University of Waterloo
- "Constant-Size Commitments to Polynomials and Their Applications"
- 5 July 2010: Qi Xie, University of Waterloo
- "Privacy-Preserving Interest Matching for Mobile Social Networking"
- 25 June 2010: Michael Reiter, University of North Carolina
- "Defending Against Client Compromises in Client-Server Applications"
- 21 Jun 2010: Can Tang, University of Waterloo
- "An Improved Algorithm for Tor Circuit Scheduling"
- 27 May 2010: Aniket Kate, University of Waterloo
- "Distributed Private-Key Generators for Identity-Based Cryptography"
- 11 May 2010: Roger Dingledine, The Tor Project
- "Tor and censorship: lessons learned"
- 7 May 2010: Rachel Greenstadt, Drexel University
- "Privacy & Stylometry: Exploring the Limitations and Potential of Automated Authorship Recognition"
2009-2010 (MITACS Speaker Series on Privacy)
- 19 March 2010: Rosario Gennaro, IBM Research
- "Non-Interactive Verifiable Computing: Outsourcing Computation to Untrusted Workers"
- 9 March 2010: Tadayoshi Kohno, University of Washington
- "Increasing Privacy with Self-destructing Data"
- 5 March 2010: Wanying Luo, University of Waterloo
- "Designing a Privacy-Aware Location Proof Architecture"
- 5 February 2010: Jeremy Clark, University of Waterloo
- "The First Governmental Election with a Voter Verifiable Tally: Experiences using Scantegrity II at Takoma Park"
- 15 January 2010: Nick Hopper, University of Minnesota
- "Scalable Anonymous Overlay Networks"
- 14 January 2010: Aniket Kate, University of Waterloo
- "Using Sphinx to Improve Onion Routing Circuit Construction"
- 3 December 2009: Sherman Chow, New York University
- "Improving Privacy and Security in Multi-Authority Attribute-Based Encryption"
- 1 December 2009: Periklis Papakonstantinou, University of Toronto
- "On the Impossibility of Basing Identity Based Encryption on Trapdoor Permutations"
- 29 October 2009: Berkant Ustaoğlu, NTT Information Sharing Platform Laboratories
- "Multi-party Off-the-Record Messaging"
- 15 October 2009: Greg Zaveruca, University of Waterloo
- "The Identity Mixer Anonymous Credential System"
- 1 October 2009: Jason Hinek, University of Calgary
- "Towards Attribute-Based Encryption Without Key Delegation"
- 22 July 2009: Ian Goldberg, University of Waterloo
- "Sphinx: A Compact and Provably Secure Mix Format"
- 15 June 2009: Aniket Kate, University of Waterloo
- "Distributed Key Generation for the Internet"
- 27 May 2009: Aniket Kate, University of Waterloo
- "Anonymous Key Agreement in an Identity-Based Infrastructure"
- 8 May 2009: Prof. Nikita Borisov, University of Illinois, Urbana-Champaign
- "Peer-to-peer Anonymous Communication: Approaches and Pitfalls"
2008-2009 (MITACS Speaker Series on Privacy)
- 30 March 2009: Chris Alexander, University of Waterloo
- "Plinko: Polling with a Physical Implementation of a Noisy Channel"
- 23 February 2009: Jennifer Granick, Electronic Frontier Foundation
- "Cutting Edge Cases in Digital Privacy and Crime"
- 18 February 2009: Greg Zaverucha, University of Waterloo
- "Private Intersection of Certified Sets"
- 11 November 2008: Atefeh Mashatan, University of Waterloo
- "Message recognition protocols for ad hoc networks"
- 29 September 2008: Ontario Information and Privacy Commissioner Ann Cavoukian
- "Change the Paradigm: Embed Privacy into Technology and Ride the Next Wave"
A video of the talk is available.
- 18 September 2008: Joel Reardon, University of Waterloo
- "Improving Tor using a TCP-over-DTLS tunnel"
- 19 August, 2008: Kevin Henry, University of Waterloo
- "The theory and applications of homomorphic cryptography"
- 16 July 2008: Ge Zhong, University of Waterloo
- "Distributed approaches for location privacy"
- 9 July 2008: Ryan Stedman, University of Waterloo
- "A user study of Off-the-Record Messaging"
- 2 July 2008: Maura Paterson, Royal Holloway, University of London
- "Aspects of key management in wireless sensor networks"
- 9 June 2008: Chengxi Zhang, University of Waterloo
- "On achieving security and privacy preservation for vehicular communications"
- 8 April 2008: Stefan Saroiu, University of Toronto
- "Towards eradicating phishing attacks"
