index.json

[{"authors":["alexandra-mendes"],"categories":null,"content":"","date":1659346512,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1659346512,"objectID":"f9764b34b407180acbcca641e6af5e24","permalink":"/author/alexandra-mendes/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/alexandra-mendes/","section":"authors","summary":"","tags":null,"title":"Alexandra Mendes","type":"authors"},{"authors":["jff"],"categories":null,"content":"","date":1659346512,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1659346512,"objectID":"5c59ce41b7fde571ab924e62dc236181","permalink":"/author/joao-f.-ferreira/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/joao-f.-ferreira/","section":"authors","summary":"","tags":null,"title":"João F. Ferreira","type":"authors"},{"authors":["rafael-prates"],"categories":null,"content":"","date":1656547200,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1656547200,"objectID":"8c1bb01cc4d6a042611a7ff8c8e8fc05","permalink":"/author/rafael-prates/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/rafael-prates/","section":"authors","summary":"","tags":null,"title":"Rafael Prates","type":"authors"},{"authors":["carolina-carreira"],"categories":null,"content":"","date":1651881600,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1651881600,"objectID":"8d42a6291472d6527b7bbeebb1b0434b","permalink":"/author/carolina-carreira/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/carolina-carreira/","section":"authors","summary":"","tags":null,"title":"Carolina Carreira","type":"authors"},{"authors":["joao-campos"],"categories":null,"content":"","date":1651881600,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1651881600,"objectID":"ac59ce38db5f3740d1c696a28b0a0cbb","permalink":"/author/joao-campos/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/joao-campos/","section":"authors","summary":"","tags":null,"title":"João Campos","type":"authors"},{"authors":["miguel-grilo"],"categories":null,"content":"","date":1651881600,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1651881600,"objectID":"527de2967959363e9d7521d7169b24fa","permalink":"/author/miguel-grilo/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/miguel-grilo/","section":"authors","summary":"","tags":null,"title":"Miguel Grilo","type":"authors"},{"authors":["pedro-freitas"],"categories":null,"content":"","date":1651276800,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1651276800,"objectID":"3115e4869f26c1f4b96b1a6bc419232b","permalink":"/author/pedro-freitas/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/pedro-freitas/","section":"authors","summary":"","tags":null,"title":"Pedro Freitas","type":"authors"},{"authors":["jose-almeida"],"categories":null,"content":"","date":-62135596800,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":-62135596800,"objectID":"bafe8705bdb07f3a9b5db2b7e8e4f878","permalink":"/author/jose-bacelar-almeida/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/jose-bacelar-almeida/","section":"authors","summary":"","tags":null,"title":"José Bacelar Almeida","type":"authors"},{"authors":["nicolas"],"categories":null,"content":"","date":-62135596800,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":-62135596800,"objectID":"a0a398664e0a14d6e3115a53fa05179d","permalink":"/author/nicolas-christin/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/nicolas-christin/","section":"authors","summary":"","tags":null,"title":"Nicolas Christin","type":"authors"},{"authors":["pedro-carrott"],"categories":null,"content":"","date":-62135596800,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":-62135596800,"objectID":"4fa910c2b4e8bfeaefffe1d4d2618027","permalink":"/author/pedro-carrott/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/pedro-carrott/","section":"authors","summary":"","tags":null,"title":"Pedro Carrott","type":"authors"},{"authors":[],"categories":null,"content":"Slides can be added in a few ways:\n Create slides using Wowchemy\u0026rsquo;s Slides feature and link using slides parameter in the front matter of the talk file Upload an existing slide deck to static/ and link using url_slides parameter in the front matter of the talk file Embed your slides (e.g. Google Slides) or presentation video on this page using shortcodes.  Further event details, including page elements such as image galleries, can be added to the body of this page.\n","date":1906549200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1906549200,"objectID":"a8edef490afe42206247b6ac05657af0","permalink":"/event/example/","publishdate":"2017-01-01T00:00:00Z","relpermalink":"/event/example/","section":"event","summary":"An example event.","tags":[],"title":"Example Event","type":"event"},{"authors":["Steve Dunne","João F. Ferreira","Alexandra Mendes","Campbell Ritchie","Bill Stoddart","Frank Zeyda"],"categories":[],"content":"Related  A wp Calculus for a Preferential Computations: Mechanisation in Isabelle/HOL (Technical report)  ","date":1659346512,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1659346512,"objectID":"c9f44d5039644efd9379c7ab7c9844a5","permalink":"/publication/2022/jlamp/","publishdate":"2022-08-01T10:35:12+01:00","relpermalink":"/publication/2022/jlamp/","section":"publication","summary":"We present an imperative refinement language for the development of backtracking programs and discuss its semantic foundations. For expressivity, our language includes prospective values and preference — the latter being a variant of Nelson’s biased choice that backtracks from infeasibility of a continuation. Our key contribution is to examine feasibility-preserving refinement as a basis for developing backtracking programs, and several key refinement laws that enable compositional refinement in the presence of non-monotonic program combinators.","tags":[],"title":"bGSL: An Imperative Language for Specification and Refinement of Backtracking Programs","type":"publication"},{"authors":["Rafael Prates"],"categories":[],"content":"","date":1656547200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1656547200,"objectID":"2117e67828eb94e94b11dffe00c890a9","permalink":"/publication/2022/rafael-prates-thesis/","publishdate":"2022-06-30T00:00:00Z","relpermalink":"/publication/2022/rafael-prates-thesis/","section":"publication","summary":"Password-based authentication is still the dominant form of authentication on the web, yet users do not adopt password managers for fear of them being insecure, unreliable and other reasons. In this project we modify a password manager to try to comply with certain data security properties as a way to increase adoption of this type of software that has been increasing in importance.\nTaking BitWarden’s Google Chrome extension as our chosen password manager, we define password manager states and data security properties regarding the master password that we would like to comply with, perform tests and analyse password retention problems in the application. While the BitWarden extension interacts with many layers, we decided to only change the application layer, as a way to understand how much can be done by the developers of these types of applications.\nWe then introduce our modified extensions that try to solve the issues presented before and introduce a testing framework that is able to automatically interact with the extension through the graphical user interface to replicate the use case chosen. While our solution does not completely solve the issue, we were able to reduce the problem slightly.","tags":[],"title":"Persistence of Passwords in Bitwarden's Browser Extension: Unnecessary Retention and Solutions","type":"publication"},{"authors":[],"categories":[],"content":"Members of the PassCert research team attended iFM 2022, the 17th International Conference on integrated Formal Methods.\nThe two papers presented were:\n  Studying Users' Willingness to Use a Formally Verified Password Manager, Carolina Carreira (presented at the PhD Symposium)\n  Verified Password Generation from Password Composition Policies, Miguel Grilo, João Campos, João F. Ferreira, José Bacelar Almeida and Alexandra Mendes\n ","date":1654624098,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1654624098,"objectID":"3d042529e9f42d4b4c1d89bb74185cb2","permalink":"/post/22-06-07-ifm-lugano/","publishdate":"2022-06-07T17:48:18Z","relpermalink":"/post/22-06-07-ifm-lugano/","section":"post","summary":"Members of the PassCert research team attended iFM 2022, the 17th International Conference on integrated Formal Methods.\n","tags":[],"title":"PassCert presentations at iFM 2022","type":"post"},{"authors":["Carolina Carreira"],"categories":[],"content":"","date":1651881600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1651881600,"objectID":"46298b259977b51abc1790db537df433","permalink":"/publication/2022/ifm-phd/","publishdate":"2022-05-07T22:42:47Z","relpermalink":"/publication/2022/ifm-phd/","section":"publication","summary":"Password Managers (PMs) help users manage their passwords safely but many users do not trust them. To mitigate users' doubts, formal verification can be used. Formal verification can guarantee the absence of errors and make PMs more reliable. Nonetheless, the impact it has on the adoption of formally verified software is unknown. In previous work, we performed a preliminary user study which suggests that formal verification increases users’ willingness to use PMs. However, a large-scale study is required to confirm our findings. As such we designed and plan to deploy a large-scale study to confirm our previous work and gather further insight on users’ perceptions of formal verification in PMs.","tags":[],"title":"Studying Users' Willingness to Use a Formally Verified Password Manager","type":"publication"},{"authors":["Miguel Grilo","João Campos","João F. Ferreira","José Bacelar Almeida","Alexandra Mendes"],"categories":[],"content":"","date":1651881600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1651881600,"objectID":"5e2df45722f6b3022a9f05f4d8083d63","permalink":"/publication/2022/ifm/","publishdate":"2022-05-07T22:42:47Z","relpermalink":"/publication/2022/ifm/","section":"publication","summary":"Password managers (PMs) are important tools that enable the use of stronger passwords, freeing users from the cognitive burden of remembering them. Despite this, there are still many users who do not fully trust PMs. In this paper, we focus on a feature that most PMs offer that might impact the user’s trust, which is the process of generating a random password. We present three of the most commonly used algorithms and we propose a solution for a formally verified reference implementation of a password generation algorithm. We use EasyCrypt to specify and verify our reference implementation. In addition, we present a proof-of-concept prototype that extends Bitwarden to only generate compliant passwords, solving a frequent users’ frustration with PMs. This demonstrates that our formally verified component can be integrated into an existing (and widely used) PM.","tags":[],"title":"Verified password generation from password composition policies","type":"publication"},{"authors":["Pedro Freitas"],"categories":[],"content":"","date":1651276800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1651276800,"objectID":"720fc43ad24cae202df88f1e165f7bf8","permalink":"/publication/2022/pedro-freitas-thesis/","publishdate":"2022-04-30T00:00:00Z","relpermalink":"/publication/2022/pedro-freitas-thesis/","section":"publication","summary":"","tags":[],"title":"Implementação Certificada da Componente Criptográfica do Gestor de Passwords KeePass","type":"publication"},{"authors":["João F. Ferreira","João Campos"],"categories":[],"content":"Our SmartPasswords extension was accepted by the Bitwarden team! The feature will be merged into the product after a process of code review, benefitting millions of users.\nThe new feature Smart Passwords, developed in the context of João Campos\u0026rsquo;s MSc thesis, reads the field passwordrules in an input form. This field contains the password policies specified by the website, making it easier for the generator to generate compliant passwords.\nTo specify the policy annotations (i.e., password rules), the extension uses a language developed by Apple. It also uses a new npm package developed by our team, based on Apple\u0026rsquo;s own parser and adapted to Typescript (@passcert/pwrules-annotations).\nFor example, the specification\npasswordrules=\u0026quot;required: upper; required: lower; required:digit; required: special; minlength: 10;\u0026quot;\nspecifies a password that must have at least 10 characters, and at least one lowercase letter, one uppercase letter, one digit, and one symbol. Since all character classes are required, the checkboxes are disabled and the minimum number of digits and symbols is also disabled because changing these values would generate a password that would be uncompliant. The minimum length of the password is also capped at 10.\nRelated publications   Verified Password Generation from Password Composition Policies, Miguel Grilo, João Campos, João F. Ferreira, José Bacelar Almeida and Alexandra Mendes\n  SmartPasswords: Increasing Password Managers' Usability by Generating Compliant Passwords, João Campos\u0026rsquo;s MSc thesis\n ","date":1637862498,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1637862498,"objectID":"418882b90a8e20f63d471d21cb34ee37","permalink":"/post/21-11-25-smartpasswords-bw/","publishdate":"2021-11-25T17:48:18Z","relpermalink":"/post/21-11-25-smartpasswords-bw/","section":"post","summary":"Our SmartPasswords extension was accepted by the Bitwarden team! The feature will be merged into the product after a process of code review, benefitting millions of users.\n","tags":[],"title":"SmartPasswords extension accepted by Bitwarden team","type":"post"},{"authors":["Carolina Carreira","João F. Ferreira","Alexandra Mendes","Nicholas Christin"],"categories":[],"content":"","date":1637625600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1637625600,"objectID":"54cf20a4264a60f0f4c61d14cc0df58a","permalink":"/publication/2021/appfm/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2021/appfm/","section":"publication","summary":"As software becomes more complex and assumes an even greater role in our lives, formal verification is set to become the gold standard in securing software systems into the future, since it can guarantee the absence of errors and entire classes of attack. Recent advances in formal verification are being used to secure everything from unmanned drones to the internet. At the same time, the usable security research community has made huge progress in improving the usability of security products and end-users comprehension of security issues. However, there have been no human-centered studies focused on the impact of formal verification on the use and adoption of formally verified software products. We propose a research agenda to fill this gap and to contribute with the first collection of studies on people’s mental models on formal verification and associated security and privacy guarantees and threats. The proposed research has the potential to increase the adoption of more secure products and it can be directly used by the security and formal methods communities to create more effective and secure software tools.","tags":[],"title":"Exploring Usable Security to Improve the Impact of Formal Verification: A Research Agenda","type":"publication"},{"authors":["Miguel Grilo"],"categories":[],"content":"","date":1637193600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1637193600,"objectID":"39ad11c6e994a97844e29cd9409ccc0a","permalink":"/publication/2021/miguel-grilo-thesis/","publishdate":"2021-11-18T00:00:00Z","relpermalink":"/publication/2021/miguel-grilo-thesis/","section":"publication","summary":"Password managers are important tools that enable us to use stronger passwords, freeing us from the cognitive burden of remembering them. Despite this, there are still many users who do not fully trust password managers. In this work, we focus on a feature that most password managers offer that might impact the user’s trust, which is the process of generating random passwords. We survey which algorithms and protocols are most commonly used and we propose a solution for a formally verified reference implementation of a password generation algorithm. Finally, we realize this reference implementation in Jasmin and we prove that the concrete implementation preserves the verified properties. We use EasyCrypt as our proof framework and Jasmin as our programming language.","tags":[],"title":"Formal Verification of Password Generation Algorithms used in Password Managers","type":"publication"},{"authors":["Carolina Carreira"],"categories":[],"content":"","date":1637193600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1637193600,"objectID":"1c2fb71d68ed75201c313f01390415aa","permalink":"/publication/2021/carolina-carreira-thesis/","publishdate":"2021-11-18T00:00:00Z","relpermalink":"/publication/2021/carolina-carreira-thesis/","section":"publication","summary":"Password Managers (PMs) are useful tools to manage passwords but they are not widely used. Studies indicate usability problems and distrust from users as the reasons for the low adoption of PMs. As such, we propose extending an existing PM by implementing relevant usability best practices and increasing transparency by educating users about how PMs work. This project is part of the PassCert research project, which aims to build a formally verified PM. Therefore, another goal is to explore ways that effectively convey to users the formally verified properties. We performed user studies that suggest that our solution improves the usability of the PM and that we were able to convey relevant information about its formally verified features. We contribute with the first study on users’ perceptions of formal verification on PMs and hope that our findings can help the formal verification security community better communicate with end-users.","tags":[],"title":"On Usable Security and Verified Password Managers","type":"publication"},{"authors":["João Campos"],"categories":[],"content":"","date":1637193600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1637193600,"objectID":"0cdf164ea26f7dce68e29fde4d26601b","permalink":"/publication/2021/joao-campos-thesis/","publishdate":"2021-11-18T00:00:00Z","relpermalink":"/publication/2021/joao-campos-thesis/","section":"publication","summary":"Passwords are still the go-to method to provide efficient user authentication in web applications, despite research showing that users usually choose weak passwords and reuse them across different services. Security experts advocate the usage of password managers. These tools can improve account security by enabling the utilization of unique and robust passwords, simultaneously improving the usability and convenience of text password authentication. However, these tools are not prepared to deal with overly restrictive password composition policies, which many websites employ. These policies pose challenges to password managers and may impact their usage: users become frustrated when generated passwords do not comply with such policies. We aim to solve this problem by 1) combining a language capable of describing password rules and a widely used password manager --- Bitwarden ---, and 2) expanding said language to express policies suggested by experts, which combine security and usability. We generated compliant passwords for every policy tested with our prototype, and Bitwarden accepted our solution to incorporate in their final product. These results are encouraging and suggest that password managers benefit from this ability to interpret password policies, which is a further step to increase the adoption of password managers.","tags":[],"title":"SmartPasswords: Increasing Password Managers' Usability by Generating Compliant Passwords","type":"publication"},{"authors":["Rui Lima","João F. Ferreira","Alexandra Mendes"],"categories":[],"content":"","date":1636502400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1636502400,"objectID":"fcde28bf97a7f1f2cfcc3b8fe3e4b871","permalink":"/publication/2021/iwor/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2021/iwor/","section":"publication","summary":"Vulnerability  detection  and  repair  is  a  demanding and  expensive  part  of  the  software  development  process.  As such,  there  has  been  an  effort  to  develop  new  and  better  ways to  automatically  detect  and  repair  vulnerabilities.  DifFuzz  is a  state-of-the-art  tool  for  automatic  detection  of  timing  side-channel vulnerabilities, a type of vulnerability that is particularly difficult to detect and correct. Despite recent progress made with tools  such  as  DifFuzz,  work  on  tools  capable  of  automatically repairing  timing  side-channel  vulnerabilities  is  scarce.  In  this paper, we propose DifFuzzAR, a new tool for automatic repair of timing side-channel vulnerabilities in Java code. The tool works in  conjunction  with  DifFuzz  and  it  is  able  to  repair  56%  of  thevulnerabilities  identified  in  DifFuzz’s  dataset.  The  results  show that the tool can indeed automatically correct timing side-channel vulnerabilities, being  more effective with  those that  are control-flow  based.","tags":[],"title":"Automatic Repair of Java Code with Timing Side-Channel Vulnerabilities","type":"publication"},{"authors":["Carolina Carreira","João F. Ferreira","Alexandra Mendes"],"categories":[],"content":"","date":1631232000,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1631232000,"objectID":"35df94b970d50c6392786a9192ea26e0","permalink":"/publication/2021/inforum/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2021/inforum/","section":"publication","summary":"Security  experts  strongly  recommend  the  use  of  Password Managers (PMs). However, PMs are not widely used and studies indicate usability problems and distrust from users as the reasons for their low adoption. In this paper, we review usability challenges of PMs and we propose the use of known usability best practices and techniques to extend and improve Bitwarden, a widely-popular open-source PM. Since this  work  is  done  in  the  context  of  the  PassCert  project,  which  aims to build a formally verified PM, we also investigate ways to effectivelyconvey  to  users  the  formally  verified  properties.  We  report  on  preliminary results and we propose a methodology to evaluate our extension of Bitwarden and to determine the impact of formal verification on the adoption of PMs.","tags":[],"title":"Towards Improving the Usability of Password Managers","type":"publication"},{"authors":[],"categories":[],"content":"Members of the PassCert research team attended INFORUM 2021, the Portuguese Informatics Symposium, and presented work in progress.\nThe three talks presented were:\n  Towards Improving the Usability of Password Managers, Carolina Carreira, João F. Ferreira and Alexandra Mendes\n  Towards Formal Verification of Password Generation Algorithms used in Password Managers, Miguel Grilo, João F. Ferreira and José Bacelar Almeida\n  Certification of a Password Manager\u0026rsquo;s Cryptographic Component, Pedro Freitas\n  Photos    Carolina Carreira     Miguel Grilo     Pedro Freitas   ","date":1631209698,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1631209698,"objectID":"ab4c6b1a02eeb38a8d434b71ed14c379","permalink":"/post/21-09-09-inforum/","publishdate":"2021-09-09T17:48:18Z","relpermalink":"/post/21-09-09-inforum/","section":"post","summary":"Members of the PassCert research team attended INFORUM 2021, the Portuguese Informatics Symposium, and presented work in progress.\n","tags":[],"title":"PassCert presentations at INFORUM 2021","type":"post"},{"authors":[],"categories":[],"content":"We have an open research assistant / Ph.D. student position in the PassCert project! The focus is on the application of formal methods to password security. The successful candidate will work from INESC-ID in beautiful Lisbon, Portugal and collaborate closely with the PassCert team. We are open to discuss the possibility of remote working.\nThe deadline for application is 12 March 2021. More details\n STARTING DATE: March 2021 DURATION: 6 months, extendable (the funding is guaranteed for the first year) LOCATION: Lisbon, Portugal (possibly remote) QUALIFICATIONS: Applicants must hold a Master\u0026rsquo;s degree in Computer Science and Engineering or related fields APPLICATION DEADLINE: 12 March 2021  The selected candidate will:\n Contribute to the collection of functional and security requirements for the proof-of-concept password manager and to the identification of properties that will be formally verified. Formally verify properties relevant to password managers (e.g. properties on generation of secure passwords and properties related to data location). Contribute to the development of the proof-of-concept verified password manager. Actively participate in and contribute to PassCert\u0026rsquo;s activities and regular meetings.  Full details, including applicable legislation and application procedures are all available in the public notice: http://www.eracareers.pt/opportunities/index.aspx?task=global\u0026jobId=131478\nIf you have any questions, feel free to get in touch with João F. Ferreira.\nAbout Instituto Superior Técnico - University of Lisbon / INESC-ID Instituto Superior Técnico (IST) is part of the University of Lisbon and is the leading school of engineering in Portugal and among the ARWU top-20 engineering schools in all of Europe. The school aims to contribute to the development of society, promoting excellence in higher education, in the fields of Architecture, Engineering, Science, and Technology by promoting Research, Development, and Innovation activities.\nINESC-ID is an R\u0026amp;D institute dedicated to advanced research and development in the fields of Information Technologies, Electronics, Communications, and Energy, privately owned by IST and INESC. Working in close collaboration with faculty from IST, INESC-ID is the main research center for combined Computer Science and Engineering (CSE) and Electrical and Computer Engineering (ECE) in Portugal.\n","date":1613238498,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1613238498,"objectID":"f1fe79b050458bb2946441543b2cc6c9","permalink":"/post/21-02-12-research-assistant/","publishdate":"2021-02-13T17:48:18Z","relpermalink":"/post/21-02-12-research-assistant/","section":"post","summary":"We have an open research assistant / Ph.D. student position in the PassCert project! The focus is on the application of formal methods to password security. The successful candidate will work from INESC-ID in beautiful Lisbon, Portugal and collaborate closely with the PassCert team. We are open to discuss the possibility of remote working.\nThe deadline for application is 12 March 2021. More details\n","tags":[],"title":"Research Assistant / PhD Position available","type":"post"},{"authors":["Joshua Tan","Lujo Bauer","Nicolas Christin","Lorrie Faith Cranor"],"categories":[],"content":"","date":1588291200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1588291200,"objectID":"3d77e5d1feb5a4409d229170e4077941","permalink":"/publication/2020/ccs/","publishdate":"2020-12-25T22:42:47Z","relpermalink":"/publication/2020/ccs/","section":"publication","summary":"Multiple mechanisms exist to encourage users to create stronger passwords, including minimum-length and character-class requirements, prohibiting blocklisted passwords, and giving feedback on the strength of candidate passwords. Despite much research, there is little definitive, scientific guidance on how these mechanisms should be combined and configured to best effect. Through two online experiments, we evaluated combinations of minimum-length and character-class requirements, blocklists, and a minimum-strength requirement that requires passwords to exceed a strength threshold according to neural-network-driven password-strength estimates.\nOur results lead to concrete recommendations for policy configurations that produce a good balance of security and usability. In particular, for high-value user accounts we recommend policies that combine minimum-strength and minimum-length requirements. While we offer recommendations for organizations required to use blocklists, using blocklists does not provide further gains. Interestingly, we also find that against expert attackers, character-class requirements, traditionally associated with producing stronger passwords, in practice may provide very little improvement and may even reduce effective security.","tags":[],"title":"Practical recommendations for stronger, more usable passwords combining minimum-strength, minimum-length, and blocklist requirements","type":"publication"},{"authors":["Saul Johnson","João F. Ferreira","Alexandra Mendes","Julien Cordry"],"categories":[],"content":"","date":1580515200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1580515200,"objectID":"9d2c6f21e8e896eb1e0a35410e5a79c0","permalink":"/publication/2020/asiaccs/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2020/asiaccs/","section":"publication","summary":"The choice of password composition policy to enforce on a password-protected system represents a critical security decision, and has been shown to significantly affect the vulnerability of user-chosen passwords to guessing attacks. In practice, however, this choice is not usually rigorous or justifiable, with a tendency for system administrators to choose password composition policies based on intuition alone. In this work, we propose a methodology that draws on password probability distributions constructed from large sets of real-world password data which have been filtered according to various password composition policies. Password probabilities are then redistributed to simulate different user password reselection behaviours in order to automatically determine the password composition policy that will induce the distribution of user-chosen passwords with the greatest uniformity, a metric which we show to be a useful proxy to measure the overall resistance to password guessing attacks. Further, we show that by fitting power-law equations to the password probability distributions we generate, we can justify our choice of password composition policy without any direct access to user password data. Finally, we present Skeptic, a software toolkit that implements this methodology, including a DSL to enable system administrators with no background in password security to compare and rank password composition policies. Drawing on 205,176,321 passwords across 3 datasets, we lend validity to our approach by demonstrating that the results we obtain align closely with findings from a previous empirical study into password composition policy effectiveness.","tags":[],"title":"Skeptic: Automatic, Justified and Privacy-Preserving Password Composition Policy Selection","type":"publication"},{"authors":["David Pereira","João F. Ferreira","Alexandra Mendes"],"categories":[],"content":"","date":1577836800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1577836800,"objectID":"d6f848f88357f7793c7e58e1b5b25844","permalink":"/publication/2020/rsda/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2020/rsda/","section":"publication","summary":"In this paper we measure the accuracy of password strength meters (PSMs) using password guessing resistance against off-the-shelf guessing attacks. We consider 13 PSMs, 5 different attack tools, and a random selection of 60,000 passwords extracted from three different datasets of real-world password leaks. Our results show that a significant percentage of passwords classified as strong were cracked, thus suggesting that current password strength estimation methods can be improved.","tags":[],"title":"Evaluating the Accuracy of Password Strength Meters using Off-The-Shelf Guessing Attacks","type":"publication"},{"authors":["Sarah Pearman","Shikun Aerin Zhang","Lujo Bauer","Nicolas Christin","Lorrie Faith Cranor"],"categories":[],"content":"","date":1556668800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1556668800,"objectID":"41e08660be73e29fefac2c5542267f9d","permalink":"/publication/2019/soups/","publishdate":"2019-12-25T22:42:47Z","relpermalink":"/publication/2019/soups/","section":"publication","summary":"Security experts often recommend using password management tools that both store passwords and generate random passwords. However, research indicates that only a small fraction of users use password managers with password generators. Past studies have explored factors in the adoption of password managers using surveys and online store reviews. Here we describe a semi-structured interview study with 30 participants that allows us to provide a more comprehensive picture of the mindsets underlying adoption and effective use of password managers and password-generation features. Our participants include users who use no password-specific tools at all, those who use password managers built into browsers or operating systems, and those who use separately installed password managers. Furthermore, past field data has indicated that users of built-in, browser-based password managers more often use weak and reused passwords than users of separate password managers that have password generation available by default. Our interviews suggest that users of built-in password managers may be driven more by convenience, while users of separately installed tools appear more driven by security. We advocate tailored designs for these two mentalities and provide actionable suggestions to induce effective password manager usage.","tags":[],"title":"Why people (don’t) use password managers effectively","type":"publication"},{"authors":null,"categories":null,"content":"With the explosive growth of our data economy, the quantity of personal data and other valuable assets available online has increased massively. At the same time, despite years of searching for viable alternatives, text passwords remain the dominant access control mechanism to access that data and those assets.\nUsers’ attitudes towards passwords can thus put at risk the security of our data economy. For example, users have shown that they tend to choose weak passwords that are easy to guess by password cracking software. Moreover, many users reuse the same password across different systems, which can have serious consequences for users and organizations affected by data breaches. In the last few years, breaches at organizations like Yahoo!, Dropbox, Lastpass, LinkedIn, and eBay have exposed over a billion user passwords to attackers.\nTo address this problem, security experts recommend the use of password managers (PMs) that combine secure password storage and retrieval with random password generation. These tools can improve account security by enabling the use of strong and unique passwords, simultaneously improving the usability and convenience of text password authentication. However, despite its critical importance, the adoption of PMs is still low. Reasons for this include distrust on the storage mechanisms and on the quality of generated passwords.\nPassCert’s short-term vision is to build an open-source, proof-of-concept PM that through the use of formal verification, is guaranteed to satisfy properties on data storage and password generation. The goal is to help non-expert users to use stronger passwords without sacrificing convenience, whilst conveying the formal guarantees in an effective way. We aim to determine whether formal verification can increase users’ confidence in PMs and thus increase their adoption. The proof-of-concept PM will result from a close collaboration between researchers from INESC-ID Lisboa, INESC TEC, and The Carnegie Mellon CyLab Security and Privacy Institute.\nContacts Principal Investigator in Portugal: João F. Ferreira\nPrincipal Investigator at CMU: Nicolas Christin\nMeet the Team\nParticipant institutions:\n INESC-ID: Instituto de Engenharia de Sistemas e Computadores, Investigação e Desenvolvimento em Lisboa (INESC-ID) Instituto Superior Técnico, Universidade de Lisboa INESC TEC: Instituto de Engenharia de Sistemas e Computadores, Tecnologia e Ciência School of Computer Science, Carnegie Mellon University CyLab: Carnegie Mellon University Security and Privacy Institute  Funding PassCert is a CMU Portugal Exploratory Research Project that is funded by the Fundação para a Ciência e a Tecnologia (FCT).\n","date":1530144000,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1530144000,"objectID":"8576ec274c98b3831668a172fa632d80","permalink":"/about/","publishdate":"2018-06-28T00:00:00Z","relpermalink":"/about/","section":"","summary":"About PassCert","tags":null,"title":"PassCert﹕Exploring the Impact of Formal Verification on the Adoption of Password Security Software","type":"page"},{"authors":null,"categories":null,"content":"","date":-62135596800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":-62135596800,"objectID":"c1d17ff2b20dca0ad6653a3161942b64","permalink":"/people/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/people/","section":"","summary":"","tags":null,"title":"","type":"widget_page"}]