J
Jeff Yan
Researcher at Linköping University
Publications - 66
Citations - 3818
Jeff Yan is an academic researcher from Linköping University. The author has contributed to research in topics: CAPTCHA & Password. The author has an hindex of 24, co-authored 64 publications receiving 3497 citations. Previous affiliations of Jeff Yan include Newcastle University & University of Newcastle.
Papers
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Journal ArticleDOI
Password memorability and security: empirical results
TL;DR: To determine how to help users choose good passwords, the authors performed a controlled trial of the effects of giving users different kinds of advice.
Proceedings ArticleDOI
A low-cost attack on a Microsoft captcha
Jeff Yan,Ahmad Salah El Ahmad +1 more
TL;DR: It is shown that CAPTCHAs that are carefully designed to be segmentation-resistant are vulnerable to novel but simple attacks, including the schemes designed and deployed by Microsoft, Yahoo and Google.
Proceedings ArticleDOI
Usability of CAPTCHAs or usability issues in CAPTCHA design
Jeff Yan,Ahmad Salah El Ahmad +1 more
TL;DR: Usability issues that should be considered and addressed in the design of CAPTCHAs are discussed, and a simple but novel framework for examining CAPTCHA usability is proposed.
Proceedings ArticleDOI
Targeted Online Password Guessing: An Underestimated Threat
TL;DR: TarGuess, a framework that systematically characterizes typical targeted guessing scenarios with seven sound mathematical models, each of which is based on varied kinds of data available to an attacker, is proposed to design novel and efficient guessing algorithms.
Proceedings ArticleDOI
Breaking Visual CAPTCHAs with Naive Pattern Recognition Algorithms
Jeff Yan,A.S. El Ahmad +1 more
TL;DR: In this paper, the authors used simple pattern recognition algorithms but exploited fatal design errors that were discovered in each CAPTCHA scheme and showed that their simple attacks can also break many other schemes deployed on the Internet at the time of writing.