In this paper, we propose and evaluate Use Your Illusion, a novel mechanism for user authentication that is secure and usable regardless of the size of the device on which it is used. Our system relies on the human ability to recognize a degraded version of a previously seen image. We illustrate how distorted images can be used to maintain the usability of graphical password schemes while making them more resilient to social engineering or observation attacks. Because it is difficult to mentally "revert" a degraded image, without knowledge of the original image, our scheme provides a strong line of defense against impostor access, while preserving the desirable memorability properties of graphical password schemes.

We evaluate Website authentication measures that are designed to protect users from man-in-the-middle, 'phishing', and other site forgery attacks. We asked 67 bank customers to conduct common online banking tasks. Each time they logged in, we presented increasingly alarming clues that their connection was insecure. First, we removed HTTPS indicators. Next, we removed the participant's site-authentication image--the customer-selected image that many Websites now expect their users to verify before entering their passwords. Finally, we replaced the bank's password-entry page with a warning page. After each clue, we determined whether participants entered their passwords or withheld them. We also investigate how a study's design affects participant behavior: we asked some participants to play a role and others to use their own accounts and passwords. We also presented some participants with security-focused instructions. We confirm prior findings that users ignore HTTPS indicators: no participants withheld their passwords when these indicators were removed. We present the first empirical investigation of site-authentication images, and we find them to be ineffective: even when we removed them, 23 of the 25 (92%) participants who used their own accounts entered their passwords. We also contribute the first empirical evidence that role playing affects participants' security behavior: role-playing participants behaved significantly less securely than those using their own passwords.

To build systems shielding users from fraudulent (or phishing) websites, designers need to know which attack strategies work and why. This paper provides the first empirical evidence about which malicious strategies are successful at deceiving general users. We first analyzed a large set of captured phishing attacks and developed a set of hypotheses about why these strategies might work. We then assessed these hypotheses with a usability study in which 22 participants were shown 20 web sites and asked to determine which ones were fraudulent. We found that 23% of the participants did not look at browser-based cues such as the address bar, status bar and the security indicators, leading to incorrect choices 40% of the time. We also found that some visual deception attacks can fool even the most sophisticated users. These results illustrate that standard security indicators are not effective for a substantial fraction of users, and suggest that alternative approaches are needed.

In the last few years, Internet users have seen the rapid expansion of "phishing", the use of spoofed e-mails and fraudulent websites designed to trick users into divulging sensitive data. More recently, we have seen the growth of "pharming", the use of malware or DNS-based attacks to misdirect users to rogue websites. In this panel, we will examine the state of the art in anti-phishing solutions and explore promising directions for future research.

Phishing is a model problem for illustrating usability concerns of privacy and security because both system designers and attackers battle using user interfaces to guide (or misguide) users.We propose a new scheme, Dynamic Security Skins, that allows a remote web server to prove its identity in a way that is easy for a human user to verify and hard for an attacker to spoof. We describe the design of an extension to the Mozilla Firefox browser that implements this scheme.We present two novel interaction techniques to prevent spoofing. First, our browser extension provides a trusted window in the browser dedicated to username and password entry. We use a photographic image to create a trusted path between the user and this window to prevent spoofing of the window and of the text entry fields.Second, our scheme allows the remote server to generate a unique abstract image for each user and each transaction. This image creates a "skin" that automatically customizes the browser window or the user interface elements in the content of a remote web page. Our extension allows the user's browser to independently compute the image that it expects to receive from the server. To authenticate content from the server, the user can visually verify that the images match.We contrast our work with existing anti-phishing proposals. In contrast to other proposals, our scheme places a very low burden on the user in terms of effort, memory and time. To authenticate himself, the user has to recognize only one image and remember one low entropy password, no matter how many servers he wishes to interact with. To authenticate content from an authenticated server, the user only needs to perform one visual matching operation to compare two images. Furthermore, it places a high burden of effort on an attacker to spoof customized security indicators.

Spyware is a significant problem for most computer users. The term "spyware" loosely describes a new class of computer software. This type of software may track user activities online and offline, provide targeted advertising and/or engage in other types of activities that users describe as invasive or undesirable.While the magnitude of the spyware problem is well documented, recent studies have had only limited success in explaining the broad range of user behaviors that contribute to the proliferation of spyware. As opposed to viruses and other malicious code, users themselves often have a choice whether they want to install these programs.In this paper, we discuss an ecological study of users installing five real world applications. In particular, we seek to understand the influence of the form and content of notices (e.g., EULAs) on user's installation decisions.Our study indicates that while notice is important, notice alone may not be enough to affect users' decisions to install an application. We found that users have limited understanding of EULA content and little desire to read lengthy notices. Users found short, concise notices more useful, and noticed them more often, yet they did not have a significant effect on installation for our population. When users were informed of the actual contents of the EULAs to which they agreed, we found that users often regret their installation decisions.We discovered that regardless of the bundled content, users will often install an application if they believe the utility is high enough. However, we discovered that privacy and security become important factors when choosing between two applications with similar functionality. Given two similar programs (e.g. KaZaA and Edonkey), consumers will choose the one they believe to be less invasive and more stable. We also found that providing vague information in EULAs and short notices can create an unwarranted impression of increased security. In these cases, it may be helpful to have a standardized format for assessing the possible options and trade-offs between applications.