Presentations
- TBA
Presented at dot Security
Paris, France, Apr 21 2017
- Cryptography and Usability (panel)
Organized by NEXTLEAP Seminar Paris, France, Apr 19 2017
- Public randomness, blockchains,
and delay functions
Presented at INRIA Paris, France, Apr 19 2017
- Alternatives to Bitcoin's proof-of-work
Presented at MIT 6.892 class
Cambridge, MA, USA, Mar 10 2017
- Alternatives to Bitcoin's proof-of-work
Presented at MIT 6.892 class Cambridge, MA, USA, Mar 10 2017
- Public randomness, blockchains,
and delay functions
Presented at Hebrew University
Jerusalem, Israel, Mar 1 2017
- Public randomness, blockchains,
and delay functions
Presented at Technion - Israel Institute of Technology Haifa, Israel, Feb 26 2017
- Public randomness, blockchains,
and delay functions
Presented at Chinese University of Hong Kong
Shatin, Hong Kong, Jan 26 2017
- Bitcoin Mining, Network and Economics
Presented at theWinter School on Cryptocurrency and Blockchain Technologies
Shanghai, China, Jan 15 2017
- Bitcoin Overview
Presented at theWinter School on Cryptocurrency and Blockchain Technologies Shanghai, China, Jan 15 2017
- Challenges in secure messaging
Presented at EE 380 Computer Systems Colloquium Stanford, CA, Nov 30 2016
- Public randomness, blockchains,
and delay functions
Presented at Sungkyunkwan University
Seoul, South Korea, Nov 23 2016
- Public randomness, blockchains,
and delay functions
Presented at MIT Cryptography and Information Security Seminar Series Cambridge, MA, Nov 18 2016
- Incentives in cryptocurrencies
Presented at ECRYPT Workshop on Cryptocurrencies
Athens, Greece, June 3 2016
- Bitcoin mining
Presented at IACR Summer School on Blockchain Technologies Corfu, Greece, May 30 2016
- Bitcoin overview
Presented at IACR Summer School on Blockchain Technologies Corfu, Greece, May 30 2016
- Solvency proofs for Bitcoin exchanges
Presented at Stanford Computer Forum Annual Meeting 
Palo Alto, CA, USA, Apr 11 2016
- The Future of Bitcoin and Cryptocurrencies
Panel at 2016 RSA Conference San Francisco, CA, USA, Mar 2 2016
- EthIKS: Using Ethereum to audit a CONIKS key transparency log
Presented at BITCOIN '16
Bridgetown, Barbados, Feb 26 2016
- Why buy when you can rent? Bribery attacks on Bitcoin consensus
Presented at BITCOIN '16 Bridgetown, Barbados, Feb 26 2016
- Strong passwords
Guest talk at Clever San Francisco, CA, USA, Feb 1 2016
- Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges
École Normale Supérieure Paris, France, Nov 27 2015
- CONIKS & Secure Messaging
Institut national de recherche en informatique et en automatique (INRIA) Paris, France, Nov 26 2015
- Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges
École polytechnique fédérale de Lausanne (EPFL)
Lausanne, Switzerland, Nov 25 2015
- Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges
Berkeley Security Seminar Berkeley, CA, USA, Oct 23 2015
- Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges
ACM CCS 
Denver, CO, USA, Oct 14 2015
- Provisions: Privacy-preserving proofs of solvency for Bitcoin exchanges
Stanford Security Seminar Palo Alto, CA, USA, Oct 7 2015
- Involving academia in Bitcoin research
Scaling Bitcoin
Montreal, QC, Canada, Sep 12 2015
- Open questions about Bitcoin and related cryptocurrencies
Guest lecture, CS294 UC Berkeley Berkeley, CA, Sep 2 2015
- Wrecking Bitcoin consensus with large transactions
USENIX Security (rump session) 
Washington, DC, USA, Aug 12 2015
- Decentralizing Prediction Markets
Silicon Valley Etherium Meetup San Francisco, CA, USA, Jun 11 2015
- Emerging questions in secure messaging
Security and Human Behavior Washington, DC, USA, Jun 8 2015
- Does Bitcoin consensus actually work?
Presented at SRI Menlo Park, CA, USA, Jun 3 2015
- Research Perspectives and Challenges for Bitcoin and Cryptocurrencies
IEEE Security & Privacy San Jose, CA, USA, May 20 2015
- Building a public key directory with verifiable global consistency
Security Seminar, University of Washington 
Seattle, WA, USA, May 4 2015
- Recent developments in end-to-end encrypted messaging tools: CONIKS and more
Stanford Computer Forum Security Workshop Palo Alto, CA, USA, Apr 27 2015
- Towards reliable storage of 56-bit secrets in human memory
Stanford Security Lunch Palo Alto, CA, USA, Apr 15 2015
- CONIKS
Bay Area Security Research Summit San Francisco, CA, USA, Apr 10 2015
- Bitcoin security (panel discussion)
Presented at San Francisco Bitcoin meetup San Francisco, CA, USA, Mar 28 2015
- HSTS and HPKP in practice (video)
Presented at IETF 92 
Dallas, TX, USA, Mar 26 2015
- Towards reliable storage of 56-bit secrets in human memory
Presented at Southern Methodist University Dallas, TX, USA, Mar 25 2015
- Technical aspects of blockchain-based applications (panel discussion)
Presented at Stanford Blockchain Workshop Palo Alto, CA, USA, Mar 23 2015
- Making universal encryption usable
Presented at the NIST Cybersecurity and Consumer Protection Summit Palo Alto, CA, USA, Feb 12 2015
- Innovation in Secure Messaging
Presented at Carnegie Mellon University 
Pittsburgh, PA, USA, Feb 4 2015
- Advanced HTTPS Security: HSTS and pinning
Presented to the Internet Architecture Board
(online) Jan 14 2015 - Innovation in end-to-end encrypted communication
Presented at Real World Crypto
London, UK, Jan 9 2015
- Bitcoin as a public randomness source
Stanford Security Seminar Palo Alto, CA, USA, Dec 1 2014
- Storing 56-bit keys in human memory
Presented as a ECE Colloquium, Rutgers University 
New Brunswick, NJ, USA, Nov 19 2014
- Panel discussion
UK-US Cybersecurity Symposium 
Boston, MA, USA, Oct 31 2014
- Advanced HTTPS Security
Princeton Office of Information Technology Princeton, NJ, USA, Oct 29 2014
- Bringing cognitive science to computer security: Helping users memorize random passwords
Cognitive Science Research Seminar Princeton, NJ, USA, Oct 22 2014
- Upgrading HTTPS in midair: HSTS and key pinning in practice
Presented at ETH Zürich Zurich, Switzerland, Oct 10 2014
- Bitcoin as a public randomness source
Presented at Ruhr-Universität Bochum
Bochum, Germany, Oct 9 2014
- Upgrading HTTPS in midair: HSTS and key pinning in practice
Presented at the Universität Bonn Bonn, Germany, Oct 6 2014
- Storing 56-bit keys in human memory
Presented at the COSIC Seminar Series KU Leuven
Belgium, Oct 3 2014
- Bitcoin as a public randomness source
Cambridge Security Seminar Series Cambridge, UK, Sep 30 2014
- Why buy when you can rent? Bribery attacks on Bitcoin
Presented at USENIX Security 2014 (works-in-progress session) San Diego, CA, USA, Aug 20 2014
- EFFCUP and developments in secure messaging (with Kurt Opsahl)
Presented at USENIX Summit on Hot Topics in Security 2014 San Diego, CA, USA, Aug 19 2014
- Better in Practice than in Theory: Lessons from the Rise of Bitcoin (with Arvind Narayanan)
Presented at USENIX Summit on Hot Topics in Security 2014 San Diego, CA, USA, Aug 19 2014
- Toward reliable storage of 56-bit secrets in human memory (video)
Presented at the University of Waterloo 
Waterloo, ON, Canada, July 24 2014
- Toward reliable storage of 56-bit secrets in human memory (lightning talk)
Presented at SOUPS 2014: The Tenth Symposium On Usable Privacy and Security Menlo Park, CA, USA, July 10 2014
- Privacy concerns of implicit secondary factors for web
authentication
Presented at WAY 2014: Adventures in Authentication Workshop Menlo Park, CA, USA, July 9 2014
- Why buy when you can rent? Bribery attacks on Bitcoin
Presented at WEIS 2014: The 13th Workshop on the Economics of Information Security (rump session) State College, PA, USA, Jun 23 2014
- The future of web authentication
Presented at the Concordia University Montreal, QC, Canada, Apr 23 2014
- Tutorial on Bitcoin technologies
Presented at the Electronic Frontier Foundation San Francisco, CA, USA, Apr 9 2014
- Tutorial on Bitcoin technologies (video)
Presented at the Bitcoin and Cryptocurrency Research Conference Princeton, NJ, USA, Mar 27 2014
- FawkesCoin: Bitcoin with public-key cryptography
Presented at the Security Protocols Workshop Cambridge, UK, Mar 21 2014
- An Overview of Bitcoin, or "Bitcoin is a Full-Employment Act for Security Engineers"
Cambridge Security Seminar Series Cambridge, UK, March 18 2014
- Fixing HTTPS: New models for distributing transport security policy
Presented at Center For Information Technology Policy Princeton, NJ, USA, Mar 13 2014
- Mixcoin: Anonymity for Bitcoin with accountable mixes
Presented at Financial Crypto Bridgetown, Barbados, Mar 6 2014
- Estimating the power consumption of Bitcoin
Presented at Financial Crypto (rump session) Bridgetown, Barbados, Mar 4 2014
- The science of guessing: analyzing an anonymized corpus of 70 million passwords
Presented at the NSA Science of Cybersecurity Award Reception 
Ft Meade, MD, USA, July 17 2013
- S-links: Why distributed security policy requires secure introduction
Presented at W2SP San Francisco, CA, USA, May 24 2013
- Pins, Tacks, and Slinks: Proposals for patching PKI on the web
Cambridge Security Seminar Series Cambridge, UK, May 8 2013
- Scalable distribution of HTTPS security policies
Presented at ISSNet workshop 
Victoria, BC, Canada, Apr 24 2013
- Web authentication in practice
Presented at ISR, Carnegie Mellon University Pittsburgh, PA, USA, Feb 22 2013
- What I've learned about passwords, and why they aren't going away (video)
Presented at Mozilla San Francisco, CA, USA, Feb 4 2013
- Authenticating humans to computers: What I expect for the next 10 years (video)
Presented at Center of Information Technology Policy Princeton, NJ, USA, Nov 29 2012
- The under-utilised effectiveness of computer science in other research fields
Presented at Gates Cambridge Idea Lab Cambridge, UK, June 11 2012
- Guessing human-chosen secrets
Presented at Security and Human Behavior 2012 
New York, NY, USA, June 4 2012
- Of contraseñas, סיסמאות, and 密码: Character encoding issues for web passwords
Presented at Web 2.0 Security & Privacy San Francisco, CA, USA, May 24 2012
- The science of guessing: analyzing an anonymized corpus of 70 million passwords
Presented at the 2012 IEEE Symposium on Security and Privacy San Francisco, CA, USA, May 23 2012
- Guessing human-chosen secrets
Presented at the University of Münster Münster, Germany, May 8 2012
- Authentication in a networked world
Presented at the Gates Scholars' Easter Term Symposium Cambridge, UK, May 2 2012
- Big Data Lecture #2
Presented in Part II Additional Topics Cambridge, UK, Apr 30 2012
- Big Data Lecture #1
Presented in Part II Additional Topics Cambridge, UK, Apr 27 2012
- Guessing human-chosen secrets
Presented at Microsoft Research Redmond, WA, USA, Apr 23 2012
- Statistical metrics for individual password strength
Presented at Twentieth International Workshop on Security Protocols Cambridge, UK, Apr 12 2012
- Guessing human-chosen secrets
Presented at Microsoft Research Cambridge, UK, Apr 5 2012
- It’s Not Stealing If You Need It: A panel on the ethics of performing research using public data of illicit origin
(with Serge Egelman, Sonia Chiasson, David Dittrich and Stuart Schechter)
Panel discussion at WECSR '12: Workshop on Ethics in Computer Security Research
Kralendijk, Bonaire, Netherlands, Mar 2 2012
- Linguistic properties of multi-word passphrases
Presented at USEC '12: Workshop on Usable Security. Kralendijk, Bonaire, Netherlands, Mar 2 2012
- Questions to which the answer is no (passwords edition)
Presented at FC'12: The Sixteenth International Conference on Financial Cryptography and Data Security (rump session) Kralendijk, Bonaire, Netherlands, Feb 27 2012
- A birthday present every eleven wallets? The security of customer-chosen banking PINs
Presented at FC'12: The Sixteenth International Conference on Financial Cryptography and Data Security Kralendijk, Bonaire, Netherlands, Feb 27 2012
- User authentication on the web
Guest lecture for Part II Security course Cambridge, UK, Feb 22 2012. - User choice of PINs and passphrases
Cambridge Security Seminar Series Cambridge, UK, Jan 24 2012
- Getting web authentication right
Presented at the Nineteenth International Workshop on Security Protocols Cambridge, UK, Mar 28 2011. - Authentication in the Social Web
Presented at the Workshop on the future of social networking Cambridge, UK, Nov 18 2010. - Human authentication on the web
Guest lecture for Part II Security course Cambridge, UK, Nov 17 2010. - Side Channel Cryptanalysis
Presented at the Current Research Topics Lecture Series Cambridge, UK, Nov 5 2010
- The challenges of online protest
Presented at the 2010 Festival of Ideas Cambridge, UK, Oct 23 2010 - Human-generated secret data
Presented at Security and Human Behaviour 2010 Cambridge, UK, Jun 29 2010 - Cryptographic implementation attacks
Presented to Checkpoint Security Cambridge, UK, Jun 25 2010 - Security and social networks
Presented to Checkpoint Security Cambridge, UK, Jun 22 2010 - The challenges of online protest
Presented at the Third Annual Global Scholars' Symposium Cambridge, UK, Jun 12 2010 - Passwords and intimacy
Presented at the WEIS 2010: The Ninth Workshop on the Economics of Information Security (rump session) Cambridge, MA, USA, Jun 8 2010
- The password thicket: technical and market failures in human authentication on the web
Presented at the WEIS 2010: The Ninth Workshop on the Economics of Information Security Cambridge, MA, USA, Jun 7 2010 (paper)
- Side Channel Cryptanalysis
Presented at the Current Research Topics Lecture Series Cambridge, UK, May 4 2010
- New Directions in Online Protest
Presented at the Eighteenth International Workshop on Security Protocols Cambridge, UK, Mar 24 2010
- Internet Censorship and Resistance
Presented at the Gates Scholars' Lent Symposium 2010 Cambridge, UK, Feb 2 2010
- New Directions in Online Protest
Presented at FC'10: The Fourteenth International Conference on Financial Cryptography and Data Security (rump session)
Tenerife, Spain, Jan 26 2010
- What's in a Name? Evaluating Statistical Attacks on Personal Knowledge Questions
Presented at FC'10: The Fourteenth International Conference on Financial Cryptography and Data Security Tenerife, Spain, Jan 26 2010 (paper)
- Statistical Attacks on Personal Knowledge Questions
Presented at Computer Laboratory Security Group meeting Cambridge, UK, Jan 22 2010
- Security and Privacy in Social Networks
Presented to the EFF San Francisco, CA, USA, Dec 21 2009. - Security and Personal Knowledge
Presented to security research group University of Hertfordshire, Hatfield, UK, Dec 2 2009 - Security and Social Networks
Guest Lecture for Part II Security course Cambridge, UK, Nov 23 2009 - Security and Social Networks
Presented at the SPION Workshop Katholieke Universiteit Leuven, Belgium, Nov 5 2009 - Security and Personal Knowledge
Presented to COSIC research group Katholieke Universiteit Leuven, Belgium, Nov 4 2009 - Security and Social Networks
Presented to Checkpoint Security Cambridge, UK, Sep 7 2009 - Prying Data out of a Social Network (talk cancelled, slides only)
Presented at ASONAM 2009: The 2009 International Conference on Social Network Analysis and Mining Athens, Greece, Jul 20 2009
(paper) - Privacy Suites: Shared Privacy For Social Networks (poster)
Presented at SOUPS 2009: The Fifth Symposium On Usable Privacy and Security Mountain View, CA, USA, Jul 15 2009 (abstract) - Privacy Aspects of Social Graphs
Stanford Security Seminar series Palo Alto, CA, USA, Jul 14 2009 - Can Privacy Be Viral?
Presented at WEIS 2009: The Eighth Workshop on the Economics of Information Security (rump session) London, UK, Jun 25 2009 - The Privacy Jungle: On the Market for Privacy in Social Networks
Presented at the WEIS 2009: The Eighth Workshop on the Economics of Information Security London, UK, Jun 24 2009 (paper)
- Security and Social Context
Presented at the 2009 Workshop on Security and Human Behaviour Cambridge, MA, USA, Jun 12 2009
- Internet Censorship and Resistance
Presented at the 2009 Churchill College Conference on EverythingCambridge, UK, May 15 2009
- Unique Security Challenges for Online Social Networks (Invited Talk)
Presented at FORWARD 2009: The Second ICT-FORWARD Workshop Saint-Jean-Cap-Ferrat, France, May 4 2009 (talk abstract)
- Alice and Bob in Love: Cryptographic Communication Using Natural Entropy
Presented at the Seventeenth International Workshop on Security Protocols 2009 Cambridge, UK, Apr 2 2009 (paper)
- Eight Friends are Enough: Social Graph Approximation via Public Listings
Presented at SocialNets 2009: The Second ACM Workshop on Social Network Systems Nurembeg, Germany, Mar 31 2009 (paper)
- Privacy Implications of Public Listings on Social Networks
Cambridge Security Seminar Series Cambridge, UK, Mar 24 2009 (paper)
- Privacy Implications of Social Networks
Presented at the Gates Scholars' Lent Symposium 2009 Cambridge, UK, Mar 1 2009