CUPS - CyLab Usable Privacy
					  and Security Laboratory -
					  Carnegie Mellon University,
					  5000 Forbes Ave.,
					  Pittsburgh, PA 15213

The CyLab Usable Privacy and Security Laboratory (CUPS) brings together researchers working on a diverse set of projects related to understanding and improving the usability of privacy and security software and systems. Our research employs a combination of three high-level strategies to make secure systems more usable: building systems that "just work" without involving humans in security-critical functions; making secure systems intuitive and easy to use; and teaching humans how to perform security-critical tasks.

CUPS is affiliated with Carnegie Mellon CyLab. CUPS students come from several CMU PhD programs including the programs in Societal Computing, Engineering and Public Policy, Human Computer Interaction, Computer Science, Electrical and Computer Engineering, and Public Policy and Management. We also work with masters students from several CMU programs including MSIT-Privacy Engineering. Prospective students should apply directly to these programs.

Follow @cups_cryptocorn on twitter



Director: Lorrie Cranor

Current members: Alessandro Acquisti, Yuvraj Agrawal, Hazim Almuhimedi, Lujo Bauer, Nicolas Christin, Jessica Colnago, Julie Downs, Pardis Emami Naeini, Hana Habib, Hanan Hibshi, Candice Hoke, Mandy Holbrook, Jason Hong, Darya Kurilova, Bin Liu, Abby Marsh, Billy Melicher, Norman Sadeh, Marios Savvides, Sean Segreti, Manya Sleeper, Josh Tan, Yuan Tian, Tiffany Todd, Blase Ur

Alumni and former lab members: Idris Adjerid, Fahd Arshad, Sekhar Bhagvatula, Rebecca Hunt Balebako, Cristian Bravo-Lillo, Joanna Bresee, Luc Cesca, Justin Cranshaw, Sven Dietrich, Paul Hankes Drielsma, Adam Durity, Serge Egelman, Ian Fette, Eiji Hayashi, Naoko Hayashida, Philip Huh, Peter Klemperer, Saranga Komanduri, Cynthia Kuo, Eduardo A. Cuervo Laffaye, Alain Forget, David Gordon, Jim Graves, Matthew Geiger, Iulia Ion, Patrick Kelley, Braden Kowitz, Ponnurangam Kumaraguru, Pedro Leon, Shing-hon Lau, Janne Lindqvist, Chris Long, Ryan Mahon, Michelle Mazurek, Aleecia McDonald, Marty McGuire, Jonathan Mugan, Elaine Newton, Greg Norcie, Alessandro Oltramari, Emmanuel Owusu, Robert Reeder, Bryan Pendleton, Sasha Romanosky, Florian Schaub, Rich Shay, Steve Sheng, Fred Stutzman, Eran Toch, Janice Tsai, Kami Vaniea, Timothy Vidas , Tatiana Vlahovic, Kai Wang, Yang Wang, Jason Wiese, Shomir Wilson

Current Projects and Selected Publications

Privacy decision making | Passwords and authentication | User controllable security and privacy | Usable cyber trust indicators

    Finder logo

Privacy decision making

While most people claim to be very concerned about their privacy, they do not consistently take actions to protect it. Web retailers detail their information practices in their privacy policies, but most of the time this information remains invisible to consumers. Our research focuses on understanding how individuals make privacy-related decisions, finding ways to make privacy information more usable to consumers, and using soft-paternalism to provide privacy nudges. CUPS researchers developed a "nutrition label" for privacy and a search engine for bank privacy policies. We are also studying user attitudes about privacy on social networks, privacy for mobile apps, and as the usability and effectiveness of online tracking opt-out tools. Our Usable Privacy Policy Project is developing approaches to extracting information from natural-language privacy policies and displaying that information in useful ways for users.

Recent papers

F. Schaub, R. Balebako, A. Durity, and L. Cranor. A Design Space for Effective Privacy Notices. SOUPS 2015.

H. Almuhimedi, F. Schaub, N. Sadeh, I. Adjerid, A. Acquisti, J. Gluck, L. F. Cranor, Y. Agarwal. Your Location has been Shared 5,398 Times!: A Field Study on Mobile App Privacy Nudging. CHI2015.

A. Rao, F. Schaub, N. Sadeh. What do they know about me? Contents and Concerns of Online Behavioral Profiles. PASSAT ’14. December 2014. J. R. Reidenberg, T. D. Breaux, L. F. Cranor, B. French, A. Grannis, J. T. Graves, F. Liu, A. M. McDonald, T. B. Norton, R. Ramanath, N. C. Russell, N. Sadeh, F. Schaub. Disagreeable Privacy Policies: Mismatches between Meaning and Users’ Understanding. 42nd Research Conference on Communication, Information and Internet Policy (TPRC ’14). September 2014.

L. Cranor, A. Durity, A. Marsh, and B. Ur. Parents' and Teens' Perspectives on Privacy in a Technology-Filled World. SOUPS 2014.

Y. Wang, P. Leon, A. Acquisti, L.F. Cranor, A. Forget, N. Sadeh. A Field Trial of Privacy Nudges for Facebook. ACM SIGCHI Conference on Human Factors in Computing Systems (CHI2014). [teaser video]

Rebecca Balebako, Abigail Marsh, Jialiu Lin, Jason Hong, Lorrie Faith Cranor. The Privacy and Security Behaviors of Smartphone App Developers. Workshop on Usable Security (USEC 2014). San Diego, CA, February 23, 2014.

Rebecca Balebako, Rich Shay, and Lorrie Faith Cranor. Is Your Inseam a Biometric? A Case Study on the Role of Usability Studies in Developing Public Policy. Workshop on Usable Security (USEC 2014). San Diego, CA, February 23, 2014.

>> More privacy decision making papers ...

Passwords and authentication

To combat both the inherent and user-induced weaknesses of text-based passwords, administrators and organizations typically institute a series of rules – a password policy – to which users must adhere when choosing a password. There is consensus in the literature that a properly-written password policy can provide an organization with increased security. There is, however, less accord in describing just what such a well-written policy would be, or even how to determine whether a given policy is effective. Although it is easy to calculate the theoretical password space that corresponds to a particular password policy, it is difficult to determine the practical password space. Users may, for example, react to a policy rule requiring them to include numbers in passwords by overwhelmingly picking the same number, or by always using the number in the same location in their passwords. There is little published empirical research that studies the strategies used by actual users under various password policies. In addition, some password policies, while resulting in stronger passwords, may make those passwords difficult to remember or type. This may cause users to engage in a variety of behaviors that might compromise the security of passwords, such as writing them down, reusing passwords across different accounts, or sharing passwords with friends. Other undesirable side effects of particular password policies may include frequently forgotten passwords. In fact, the harm caused by users following an onerously restrictive password policy may be greater than the harm prevented by that policy. In this project, we seek to advance understanding of the factors that make creating and following appropriate password policies difficult, collect empirical data on password entropy and memorability under various password policies, and propose password policy guidelines to simultaneously maximize security and usability of passwords. We also explore the security and usability of some new types of passwords.

Recent papers

Blase Ur, Felicia Alfieri, Maung Aung, Lujo Bauer, Nicolas Christin, Jessica Colnago, Lorrie Faith Cranor, Henry Dixon, Pardis Emami Naeini, Hana Habib, Noah Johnson, and William Melicher. 2017. Design and Evaluation of a Data-Driven Password Meter. CHI 2017. [video preview] [BEST PAPER AWARD!]

H. Habib, J. Colnago, W. Melicher, B. Ur, S. Segreti, L. Bauer, N. Christin, and L. Cranor. Password Creation in the Presence of Blacklists. USEC 2017, February 26, 2017, San Diego, CA.

W. Melicher, B. Ur, S. Segreti, S. Komanduri, L. Bauer, N. Christin, L. Cranor. Fast, Lean, and Accurate: Modeling Password Guessability Using Neural Networks. USENIX Security, August 10-12, 2016, Austin, TX.

W. Melicher, D. Kurilova, S. Segreti, P. Kalvani, R. Shay, B. Ur, L. Bauer, N. Christin, L. F. Cranor, and M. L. Mazurek. Usability and security of text passwords on mobile devices. CHI'16.

B. Ur, J. Bees, S. Segreti, L. Bauer, N. Christin, and L. F. Cranor. CHI'16. Do users' perceptions of password security match reality? CHI 2016 Honorable Mention. [video teaser, online game]

R. Shay, S. Komanduri, A. Durity, P. Huh, M. Mazurek, S. Segreti, B. Ur, L. Bauer, N. Christin, L. Cranor. Designing Password Policies for Strength and Usability. ACM Trans. Inf. Syst. Secur. 18, 4, Article 13 (May 2016), 34 pages.

B. Ur, S. Segreti, L. Bauer, N. Christin, L. Cranor, S. Komanduri, D. Kurilova, M. Mazurek, W. Melicher and R. Shay. Measuring Real-World Accuracies and Biases in Modeling Password Guessability. USENIX Security Symposium 2015. [1-minute lightning talk video]

B. Ur, F. Noma, J. Bees, S. Segreti, R. Shay, L. Bauer, N. Christin, L Cranor. "I Added '!' At The End To Make It Secure": Observing Password Creation in the Lab. SOUPS2015.

R. Shay, L. Bauer, N. Christin, L. Cranor, A. Forget, S. Komanduri, M. Mazurek, W. Melicher, S. Segreti, and B. Ur. A Spoonful of Sugar? The Impact of Guidance and Feedback on Password-Creation Behavior. CHI 2015.

Chandrasekhar Bhagavatula, Blase Ur, Kevin Iacovino, Su Mon Kywe, Lorrie Faith Cranor, Marios Savvides. Biometric Authentication on iPhone and Android: Usability, Perceptions, and Influences on Adoption. USEC 2015, February 8, 2015.

>> More passwords papers ...

User controllable security and privacy

Managing security and privacy policies is known to be a difficult problem. It is important that new user interfaces be developed to effectively and efficiently support lay users in understanding and managing security and privacy policies - their own as well as those implemented by systems and individuals with whom they interact. Solutions in this area have traditionally taken a relatively narrow view of the problem by limiting the expressiveness of policy languages or the number of options available in templates, restricting some decisions to specific roles within the enterprise, etc. As systems grow more pervasive and more complex, and as demands for increasing flexibility and delegation continue to grow, it is imperative to take a more fundamental view that weaves together issues of security, privacy and usability to systematically evaluate key tradeoffs between expressiveness, tolerance for errors, burden on users and overall user acceptance; and develop novel mechanisms and technologies that help mitigate these tradeoffs, maximizing accuracy and trustworthiness while minimizing the time and effort required by end users. The objective of this project is to develop new interfaces that combine user-centered design principles with dialog, explanation and learning technologies to assist users in specifying and refining policies. One new policy authoring interface we have developed is a visualization technique for displaying policies in a two-dimensional "expandable grid". (See also the User controllable security and privacy project page, the Expandable grids project, Grey project, Usable security for digital home storage and Locaccino.)

Recent papers

Manya Sleeper, Lorrie Faith Cranor, and Sarah K. Pearman. 2017. Exploring Topic-Based Sharing Mechanisms. CHI 2017.

P. Klemperer, Y. Liang, M. Mazurek, M. Sleeper, B. Ur, L. Bauer, L.F. Cranor, N. Gupta, and M. Reiter. Tag, You Can See It! Using Tags for Access Control in Photo Sharing. CHI 2012.

K. Vaniea, L. Bauer, L.F. Cranor, and M.K. Reiter. Studying access control usability in the lab: Lessons learned from four studies. In LASER 2012–Learning from Authoritative Security Experiment Results, July 2012.

K. Vaniea, L. Bauer, L.F. Cranor, and M.K. Reiter. Out of sight, out of mind: Effects of displaying access-control information near the item it controls. In Proceedings of the Tenth Annual Conference on Privacy, Security and Trust, July 2012.

M. Mazurek, J.P. Arsenault, J. Bresee, N. Gupta, I. Ion, C. Johns, D. Lee, Y. Liang, J. Olsen, B. Salmon, R. Shay, K. Vaniea, L. Bauer, L.F. Cranor, G.R. Ganger, and M.K. Reiter. Access Control for Home Data Sharing: Attitudes, Needs and Practices. CHI 2010.

>> More user-controllable security and privacy papers ...

Usable Cyber Trust Indicators

When systems rely on a "human in the loop" to carry out a security-critical function, cyber trust indicators are often employed to communicate when and how to perform that function. Cyber trust indicators typically serve as warnings or status indicators that communicate information, remind users of information previously communicated, and influence user behavior. They include a variety of security- and privacy-related symbols in the operating system status bar or browser chrome, pop-up alerts, security control panels, or symbols embedded in web content. However, a growing body of literature has found the effectiveness of many of these indicators to be rather disappointing. It is becoming increasingly apparent that humans are a major cause of computer security failures and that security warnings and other cyber trust indicators are doing little to prevent humans from making security errors. In some cases, it may be possible to redesign systems to minimize the need for humans to perform security-critical functions, thus reducing or eliminating the need for security warnings. However, in many cases it may be too expensive or difficult to automate security-critical tasks, and systems may need to rely on human judgment. In these cases, it is important to situate security indicators both spatially and temporally to maximize their effectiveness, and to design them to communicate clearly to users. The goal of this research is to systematically study the effectiveness of cyber trust indicators and develop approaches to making these indicators most effective and usable. We are currently focusing on security warning dialogs. See also our work on privacy indicators on our privacy decision making research page.

Recent papers

C. Bravo-Lillo, L. Cranor, S. Komanduri, S. Schechter, M. Sleeper. Harder to Ignore? Revisiting Pop-Up Fatigue and Approaches to Prevent It. SOUPS 2014.

C. Bravo-Lillo. Improving Computer Security Dialogs: An Exploration of Attention and Habituation PhD Thesis, Engineering & Public Policy Department, Carnegie Mellon University, Pittsburgh, PA, May 2014.

C. Bravo-Lillo, L.F. Cranor, J. Downs, S. Komanduri, R.W. Reeder, S. Schechter, and M. Sleeper. Your Attention Please: Designing security-decision UIs to make genuine risks harder to ignore. In Proceedings of the Eight Symposium On Usable Privacy and Security (SOUPS ’13), Newcastle, United Kingdom, 2013.

L. Bauer, C. Bravo-Lillo, L. Cranor, and E. Fragkaki. Warning Design Guidelines. CMU-CyLab-13-002. February 5, 2013.

C. Bravo-Lillo, L. Cranor, J. Downs, S. Komanduri, S. Schechter, and M. Sleeper, Operating system framed in case of mistaken identity: Measuring the success of web-based spoofing attacks on OS password-entry dialogs, in Proceedings of the 19th ACM Conference on Computer and Communications Security, ACM, 18 October 2012.

C. Bravo-Lillo, L.F. Cranor, J.S. Downs, S. Komanuri. Bridging the Gap in Computer Security Warnings: A Mental Model Approach. IEEE Security & Privacy, 2011: 18-26.

>> More usable cyber trust indicators papers ...

Earlier Projects

Looking for some of our work that you can't find under "current projects"? Check here for our past projects.

Supporting trust decisions

When Internet users are asked to make "trust" decisions they often make the wrong decision. Implicit trust decisions include decisions about whether or not to open an email attachment or provide information in response to an email that claims to have been sent by a trusted entity. Explicit trust decisions are decisions made in response to specific trust- or security-related prompts such as pop-up boxes that ask the user whether to trust an expired certificate, execute downloaded software, or allow macros to execute. Attackers are able to take advantage of most users' poor trust decision-making skills through a class of attacks known as "semantic attacks." It is not always possible for systems to make accurate trust decisions on a user's behalf, especially when those decisions require knowledge of contextual information. The goal of this research is not to make trust decisions for users, but rather to develop approaches to support users when they make trust decisions. Our research began with a mental models study aimed at understanding and modeling how people make trust decisions in the online context and ultimately resulted in the development of anti-phishing training tools and filtering software. The tools developed by this project our being commercialized by Wombat Security. For our publications, see the Supporting trust decisions project page.

Usable anonymity tools

A variety of tools have been developed to provide anonymity for various types of online interactions. Most of the work in this area has focused on improving the anonymity properties of these tools, and little has been done to improve their usability. We have been working on developing more usable interfaces for Tor.

FoxTor design document, our entry for the Tor GUI competition (selected as the phase 1 winner)

FoxTor download and FAQ

Other Selected Publications

Joshua Tan, Lujo Bauer, Joseph Bonneau, Lorrie Faith Cranor, Jeremy Thomas, and Blase Ur. 2017. Can Unicorns Help Users Compare Crypto Key Fingerprints? CHI 2017. [video preview]

M. Sleeper, A. Acquisti, L. Cranor, P. Kelley, S. Munson, NM. Sadeh. I Would Like To..., I Shouldn't..., I Wish I...: Exploring Behavior-Change Goals for Social Networking Sites. CSCW 2015: 1058-1069, Vancouver, BC, CA, March 14-18, 2015.

J. Wiese, A.J. Brush, T. Scott Saponas. Phoneprioception: enabling mobile phones to infer where they are kept. CHI 2013.

T. Vidas, E. Owusu, S. Wang, C. Zeng, and L. Cranor. QRishing: The Susceptibility of Smartphone Users to QR Code Phishing Attacks, USEC 2013 [originally published as CyLab Technical Report CMU-CyLab-12-022, November 2012].

M. Sleeper, D. Sharma, and L. Cranor. I Know Where You Live: Analyzing Privacy Protection in Public Databases. cmu-cylab-11-015, October 2011. [Extended version of paper presented at WPES 2011]

H. Hibshi, T. Vidas, and L. Cranor. Usability of Forensics Tools: A User Study. IT Security Incident Management and IT Forensics (IMF), 10-12, May 2011.

Janne Lindqvist, Justin Cranshaw, Jason Wiese, Jason Hong, and John Zimmerman. I'm the Mayor of My House: Examining Why People Use foursquare - a Social-Driven Location Sharing Application. In CHI 2011: Conference on Human Factors in Computing Systems, May 2011.

Timothy Vidas, Nicolas Christin, Lorrie Cranor. Curbing Android Permission Creep. Web 2.0 Security & Privacy 2011. Oakland, CA, May 26, 2011.

S. Garfinkel and L. Cranor. Institutional Review Boards and Your Research. Communications of the ACM, June 2010, p. 38-40. DOI =

J. Downs, M. Holbrook, S. Sheng, and L. Cranor. Are Your Participants Gaming the System? Screening Mechanical Turk Workers. CHI 2010.

Sarah Spiekermann and Lorrie Faith Cranor. Engineering Privacy. IEEE Transactions on Software Engineering. Vo. 35, No. 1, January/February, 2009, pp. 67-82.

Ahren Studer, Christina Johns, Jaanus Kase, Kyle O'Meara, Lorrie Cranor. A Survey to Guide Group Key Protocol Development. Annual Computer Security Applications Conference (ACSAC) 2008, December 8-12, 2008, Anaheim, CA.

A. McDonald and L. Cranor. How Technology Drives Vehicular Privacy. I/S: A Journal of Law and Policy for the Information Society Volume 2, Issue 3 (2006).

X. Sheng and L. Cranor. An Evaluation of the Effectiveness of US Financial Privacy Legislation Through the Analysis of Privacy Policies. I/S: A Journal of Law and Policy for the Information Society, Volume 2, Number 3, Fall 2006, pp. 943-979.

L. Cranor. 'I Didn't Buy it for Myself': Privacy and Ecommerce Personalization. Proceedings of the 2nd ACM Workshop on Privacy in the Electronic Society, October 30, 2003, Washington, DC.

L. Cranor, J. Hong, and M. Reiter. Teaching Usable Privacy and Security: A guide for instructors. 2007.

S. Egelman and L. Cranor. The Real ID Act: Fixing Identity Documents with Duct Tape. I/S: A Journal of Law and Policy for the Information Society, Volume 2, Number 1, Winter 2006, pp. 149-183.

M. Geiger and L. Cranor, Counter-Forensic Privacy Tools: A Forensic Evaluation. ISRI Technical Report. CMU-ISRI-05-119, 2005.

Romanosky, S., Acquisti, A., Hong, J., Cranor, L. F., and Friedman, B. 2006. Privacy patterns for online interactions. In Proceedings of the 2006 Conference on Pattern Languages of Programs (Portland, Oregon, October 21 - 23, 2006). PLoP '06. ACM, New York, NY, 1-9.

Security and Usability
		   book cover


Join our cups-friends mailing list for announcements about our papers and events and discussions about usable privacy and security

Security and Usability: Designing Secure Systems that People Can Use, edited by Lorrie Cranor and Simson Garfinkel, is now available

L. Cranor, J. Hong, and M. Reiter. Teaching Usable Privacy and Security: A guide for instructors. 2007.

The HCISec Bibliography contains a good list of CUPS-related publications.

HCISEC mailing list

Usable Security Blog from UC Berkeley

Slides are available from the July 2004 Workshop on Usable Privacy and Security Software

Usability, Psychology, and Security workshop

Vizsec - a research and development community interested in applying information visualization techniques to the problems of computer security

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or any of our other funders.

Privacy policy