CrySP Speaker Series on Privacy

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.

Upcoming speakers

Rearranging Power Through Law and Code: Deciphering the Canadian Encryption Debate

Lex Gill, The Citizen Lab

October 27, 2017 2:30pm, in DC 1304


The politics of encryption technology have profound implications for global security, the economy, and human rights. This talk, which is based on joint research conducted by the Citizen Lab and the Canadian Internet Policy and Public Interest Clinic, reviews the state of encryption law in Canada—from the high cost of exceptional access regimes to the possibility of compelled decryption by courts, police, and other state agents. It will also begin to explore the difficult ethical and legal questions facing technologists and computer scientists who find themselves on the frontlines of this debate. It will encourage a principled, evidence-based understanding of encryption and anonymity tools as sources of investigative friction, and present a critical set of counternarratives to the discourse of 'Going Dark.' Through the lens of encryption policy, we will explore complex questions about the outer reaches of state power, the role of intermediaries, and what it means to be secure (and free!) in the 21st century.


Lex Gill works at the intersection of technology, law, and social change. She is a research fellow at the Citizen Lab, an interdisciplinary research laboratory based at the Munk School of Global Affairs, University of Toronto and is the Advocate to the Canadian Civil Liberties Association's National Security Program. She is a former Google Policy Fellow to the Canadian Internet Policy and Public Interest Clinic and a former affiliate and researcher to the Berkman Klein Center for Internet and Society at Harvard University. Lex holds an undergraduate degree and graduate diploma from Concordia University, and a B.C.L./LL.B. from McGill University's Faculty of Law.

Somewhat Homomorphic Encryption and its Attractiveness in Privacy-Enhancing Technologies

Andreas Peter, University of Twente

November 8, 2017 10:30am, in DC 1304


In 2009, Gentry presented the first Fully Homomorphic Encryption (FHE) scheme, which roughly speaking supports arbitrary computation over encrypted data without the need to decrypt. While, theoretically, FHE schemes can be used in many settings to provide data privacy, in practice they suffer from severe efficiency drawbacks. Somewhat Homomorphic Encryption (SWHE), on the other hand, constitutes a relaxed form of FHE which only supports the computation of a limited set of functions on encrypted data (i.e., functions that can be represented as an arithmetic circuit with fixed and restricted amounts of additions and multiplications).

In this talk, I would like to give a short introduction to SWHE and show that the limited functionality of SWHE schemes can be sufficient to provide data privacy in specific application scenarios and, most importantly, can lead to constructions efficient enough for practical use. Concretely, I will look at two example applications from different domains: (1) enhancing privacy in recommender systems based on social networks and (2) privately outsourcing forensic image recognition. Using the different characteristics of these settings, I will identify some features of SWHE which make the further study of this type of encryption within the area of Privacy-Enhancing Technologies particularly worthwhile.


Andreas Peter graduated with a M.Sc. in mathematics at both the University of Cambridge (UK) and the University of Oldenburg (Germany) in 2008 and 2009, respectively. Subsequently, he received the Ph.D. in computer science from the Technical University of Darmstadt (Germany) in 2013. His Ph.D. thesis deals with the topic of secure outsourcing of computation with a special focus on homomorphic encryption. Since 2014, he is employed as an Assistant Professor at the chair of Services, Cybersecurity and Safety at the University of Twente (NL). His research interests include both fundamental and applied security and privacy aspects in IT systems with a focus on privacy-enhancing technologies, cryptographic protocol design and analysis, as well as the application and theory of functional and homomorphic encryption. He served on the program committees of several workshops and conferences devoted to information security and privacy. Since 2015, he serves on the Editorial Board of the MDPI Open Access Journal on Cryptography and the SpringerOpen EURASIP Journal on Information Security.

Past speakers


26 Jul 2017: Ross Anderson, University of Cambridge
"Making Security Sustainable"
16 Jun 2017: Prashant Nalini Vasudevan, MIT
"Average-Case Fine-Grained Hardness, and What To Do With It"
5 May 2017: Lisa Austin, University of Toronto
"Access to basic subscriber information and the Spencer Decision: disentangling normative and technological questions"


13 Mar 2017: Josh Benaloh, Microsoft Research
"Elections with both Privacy and Integrity"
3 Feb 2017: Nikita Borisov, University of Illinois, Urbana-Champaign
"The State of Secure Messaging: Ratchets, Keys, and Metadata"
2 Feb 2017: Sarah Jamie Lewis, OnionScan
"OnionScan: Practical Deanonymization of Hidden Services"
1 Feb 2017: Frank Wang, MIT
"Sieve: Cryptographically Enforced Access Control for User Data in Untrusted Clouds"
1 Dec 2016: David Murakami Wood, Queen's University
"Hack the Planet! From phone phreaking to subverting planetary infrastructures"
15 Sep 2016: Valerie Steeves, University of Ottawa
"What Hello Barbie Can Tell Us About Behavioural Targeting"
7 Jul 2016: Paul van Oorschot, Carleton University
"Password expiration policies: quantifying assumed security benefits"
10 May 2016: David Wu, Stanford University
"Constraining Pseudorandom Functions Privately"


1 Apr 2016: Seda Gürses, Princeton University
"PET Sematary: Privacy's return from the dead and the rise of Privacy Engineering"
11 Mar 2016: Eva Infeld, Darthmouth College
"Matching Theory and Anonymity"
2 Feb 2016: Alison Macrina, Library Freedom Project
"Grassroots surveillance resistance at your local library"
20 Jan 2016: Rob Jansen, Naval Research Laboratory
"Shadow: Scalable Simulation for Systems Security Research"
2 Dec 2015: Matthew Wright, University of Texas at Arlington
"Teaching Users Random System-Assigned Passwords"
1 Sep 2015: Nicholas Hopper, University of Minnesota
"Secure Load Balancing in Tor with Peerflow"
27 Jul 2015: Amir Herzberg, Bar Ilan University
"Cross-site Search Attacks: Practical Side-channel Privacy Attacks on Web Services"


5 Aug 2014: Nicholas Hopper, University of Minnesota
"New adversary models for censorship circumvention schemes"
25 Jul 2014: Joseph Bonneau, Center for Information Technology Policy
"Storing 56-bit keys in human memory"
4 Jul 2014: Christopher Parsons, University of Toronto
"Stuck on the Agenda—Lesson drawing from 'lawful access' issues in Canada"
18 Jun 2014: Radu Sion, Stony Brook University
"Modern Secure Data Management"


24 Apr 2014: Rajesh Krishna Balan, Singapore Management University
"The LiveLabs Urban LifeStyle Innovation Platform: Opportunities, Challenges, and Current Results"
27 Mar 2014: Kevin Dyer, Portland State University
"Libfte: A User-Friendly Toolkit for Constructing Practical Format-Abiding Encryption Schemes"
31 Jan 2014: Rob Johnson, Stony Brook University
"Website Fingerprinting Attacks and Defenses"
16 Dec 2013: N. Asokan, Aalto University
"On Mobile Malware"
21 Oct 2013: Kelly Caine, Clemson University
"A human-centered tool for enhancing patient privacy in electronic medical record systems"
9 Oct 2013: Patrick Traynor, Georgia Institute of Technology
"Chasing Telephony Security: Where the Wild Things... Are?"
26 Jun 2013: Vaibhav Garg, Drexel University
"Cars, Condoms, and the Privacy Paradox: A Case Study with Facebook"


16 Apr 2013: Michael Reiter, University of North Carolina
"How to Misuse, Use, and Mitigate Side Channels in Virtualized Environments"
5 Apr 2013: Claudia Diaz, KU Leuven
"Two tales of privacy in online social networks"
3 Apr 2013: Michael Brennan, SecondMuse
"Catalyzing Social Change as a Privacy and Security Technologist"
14 Mar 2013: Dawn Song, UC Berkeley
"Privacy in Emerging Technologies: Challenges, Attacks, and Defenses"
28 Jan 2013: Gabriella Coleman, McGill University
"Weapons of the Geek"
10 Oct 2012: Ian Kerr, University of Ottawa
"Repo Men Are Coming: Body EULAs, Privacy and Security of the Person"
11 Sep 2012: Patrick Ball, Benetech
"Human rights, data analysis, and the truth: technical and epistemological reflections from twenty years building software and doing analysis to study mass atrocities"
14 Aug 2012: Joel Reardon, ETH Zurich
"Data Node Encrypted File System: Efficient Secure Deletion for Flash Memory"
2 Aug 2012: Micah Sherr, Georgetown University
"Security and Privacy of Legally Authorized Telephone Surveillance"


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"


Cryptography, Security, and Privacy Research Group
David R. Cheriton School of Computer Science
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: 519-888-4567 x36163
Fax: 519-885-1208

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