A Survey on the Use of Graphical Passwords in Security
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paper_title: Recognition memory for words, sentences, and pictures

paper_content:

The S s looked through a series of about 600 stimuli selected at random from an initially larger population. They were then tested for their ability to recognize these “old” stimuli in pairs in which the alternative was always a “new” stimulus selected at random from the stimuli remaining in the original population. Depending upon whether this original population consisted solely of words, sentences, or pictures, median Ss were able correctly to recognize the “old” stimulus in 90, 88, or 98% of the test pairs, respectively. Estimated lower bounds on the informational capacity of human memory considerably exceed previously published estimates.
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paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: A Novel Cued-recall Graphical Password Scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own disadvantages. For example, cued-recall graphical password schemes are vulnerable to shoulder-surfing and cannot prevent intersection analysis attack. A novel cued-recall graphical password scheme CBFG (Click Buttons according to Figures in Grids) is proposed in this paper. Inheriting the way of setting password in traditional cued-recall scheme, this scheme is also added the ideology of image identification. CBFG helps users tend to set their passwords more complex. Simultaneously, it has the capability against shoulder surfing attack and intersection analysis attack. Experiments illustrate that CBFG has better performance in usability, especially in security.
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paper_title: UNIX Password Security - Ten Years Later

paper_content:

Passwords in the UNIX operating system are encrypted with the crypt algorithm and kept in the publicly-readable file /etc/passwd. This paper examines the vulnerability of UNIX to attacks on its password system. Over the past 10 years, improvements in hardware and software have increased the crypts/second/dollai ratio by five orders of magnitude. We reexamine the UNIX password system in light of these advances and point out possible solutions to the problem of easily found passwords. The paper discusses how the authors built some high-speed tools for password cracking and what elements were necessary for their success. These elements are examined to determine if any of them can be removed from the hands of a possible system infiltrator, and thus increase the security of the system. We conclude that the single most important step that can be taken to improve password security is to increase password entropy.
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paper_title: Making Passwords Secure and Usable

paper_content:

To date, system research has focused on designing security mechanisms to protect systems access although their usability has rarely been investigated. This paper reports a study in which users’ perceptions of password mechanisms were investigated through questionnaires and interviews. Analysis of the questionnaires shows that many users report problems, linked to the number of passwords and frequency of password use. In-depth analysis of the interview data revealed that the degree to which users conform to security mechanisms depends on their perception of security levels, information sensitivity and compatibility with work practices. Security mechanisms incompatible with these perceptions may be circumvented by users and thereby undermine system security overall.
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paper_title: A New Graphical Password Scheme Resistant to Shoulder-Surfing

paper_content:

Shoulder-surfing is a known risk where an attacker can capture a password by direct observation or by recording the authentication session. Due to the visual interface, this problem has become exacerbated in graphical passwords. There have been some graphical schemes resistant or immune to shoulder-surfing, but they have significant usability drawbacks, usually in the time and effort to log in. In this paper, we propose and evaluate a new shoulder-surfing resistant scheme which has a desirable usability for PDAs. Our inspiration comes from the drawing input method in DAS and the association mnemonics in Story for sequence retrieval. The new scheme requires users to draw a curve across their password images orderly rather than click directly on them. The drawing input trick along with the complementary measures, such as erasing the drawing trace, displaying degraded images, and starting and ending with randomly designated images provide a good resistance to shoulder-surfing. A preliminary user study showed that users were able to enter their passwords accurately and to remember them over time.
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paper_title: Password security: a case history

paper_content:

This paper describes the history of the design of the password security scheme on a remotely accessed time-sharing system. The present design was the result of countering observed attempts to penetrate the system. The result is a compromise between extreme security and ease of use.
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paper_title: Graphical passwords: a survey

paper_content:

The most common computer authentication method is to use alphanumerical usernames and passwords. This method has been shown to have significant drawbacks. For example, users tend to pick passwords that can be easily guessed. On the other hand, if a password is hard to guess, then it is often hard to remember. To address this problem, some researchers have developed authentication methods that use pictures as passwords. In this paper, we conduct a comprehensive survey of the existing graphical password techniques. We classify these techniques into two categories: recognition-based and recall-based approaches. We discuss the strengths and limitations of each method and point out the future research directions in this area. We also try to answer two important questions: "Are graphical passwords as secure as text-based passwords?"; "What are the major design and implementation issues for graphical passwords?" This survey will be useful for information security researchers and practitioners who are interested in finding an alternative to text-based authentication methods
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paper_title: Purely Automated Attacks on PassPoints-Style Graphical Passwords

paper_content:

We introduce and evaluate various methods for purely automated attacks against PassPoints-style graphical passwords. For generating these attacks, we introduce a graph-based algorithm to efficiently create dictionaries based on heuristics such as click-order patterns (e.g., five points all along a line). Some of our methods combine click-order heuristics with focus-of-attention scan-paths generated from a computational model of visual attention, yielding significantly better automated attacks than previous work. One resulting automated attack finds 7%-16% of passwords for two representative images using dictionaries of approximately 226 entries (where the full password space is 243). Relaxing click-order patterns substantially increased the attack efficacy albeit with larger dictionaries of approximately 235 entries, allowing attacks that guessed 48%-54% of passwords (compared to previous results of 1% and 9% on the same dataset for two images with 235 guesses). These latter attacks are independent of focus-of-attention models, and are based on image-independent guessing patterns. Our results show that automated attacks, which are easier to arrange than human-seeded attacks and are more scalable to systems that use multiple images, require serious consideration when deploying basic PassPoints-style graphical passwords.
---
paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: On predictive models and user-drawn graphical passwords

paper_content:

In commonplace text-based password schemes, users typically choose passwords that are easy to recall, exhibit patterns, and are thus vulnerable to brute-force dictionary attacks. This leads us to ask whether other types of passwords (e.g., graphical) are also vulnerable to dictionary attack because of users tending to choose memorable passwords. We suggest a method to predict and model a number of such classes for systems where passwords are created solely from a user's memory. We hypothesize that these classes define weak password subspaces suitable for an attack dictionary. For user-drawn graphical passwords, we apply this method with cognitive studies on visual recall. These cognitive studies motivate us to define a set of password complexity factors (e.g., reflective symmetry and stroke count), which define a set of classes. To better understand the size of these classes and, thus, how weak the password subspaces they define might be, we use the “Draw-A-Secret” (DAS) graphical password scheme of Jermyn et al. [1999] as an example. We analyze the size of these classes for DAS under convenient parameter choices and show that they can be combined to define apparently popular subspaces that have bit sizes ranging from 31 to 41—a surprisingly small proportion of the full password space (58 bits). Our results quantitatively support suggestions that user-drawn graphical password systems employ measures, such as graphical password rules or guidelines and proactive password checking.
---
paper_title: A Novel Cued-recall Graphical Password Scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own disadvantages. For example, cued-recall graphical password schemes are vulnerable to shoulder-surfing and cannot prevent intersection analysis attack. A novel cued-recall graphical password scheme CBFG (Click Buttons according to Figures in Grids) is proposed in this paper. Inheriting the way of setting password in traditional cued-recall scheme, this scheme is also added the ideology of image identification. CBFG helps users tend to set their passwords more complex. Simultaneously, it has the capability against shoulder surfing attack and intersection analysis attack. Experiments illustrate that CBFG has better performance in usability, especially in security.
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paper_title: Design and evaluation of a shoulder-surfing resistant graphical password scheme

paper_content:

When users input their passwords in a public place, they may be at risk of attackers stealing their password. An attacker can capture a password by direct observation or by recording the individual's authentication session. This is referred to as shoulder-surfing and is a known risk, of special concern when authenticating in public places. Until recently, the only defense against shoulder-surfing has been vigilance on the part of the user. This paper reports on the design and evaluation of a game-like graphical method of authentication that is resistant to shoulder-surfing. The Convex Hull Click (CHC) scheme allows a user to prove knowledge of the graphical password safely in an insecure location because users never have to click directly on their password images. Usability testing of the CHC scheme showed that novice users were able to enter their graphical password accurately and to remember it over time. However, the protection against shoulder-surfing comes at the price of longer time to carry out the authentication.
---
paper_title: Graphical passwords: a survey

paper_content:

The most common computer authentication method is to use alphanumerical usernames and passwords. This method has been shown to have significant drawbacks. For example, users tend to pick passwords that can be easily guessed. On the other hand, if a password is hard to guess, then it is often hard to remember. To address this problem, some researchers have developed authentication methods that use pictures as passwords. In this paper, we conduct a comprehensive survey of the existing graphical password techniques. We classify these techniques into two categories: recognition-based and recall-based approaches. We discuss the strengths and limitations of each method and point out the future research directions in this area. We also try to answer two important questions: "Are graphical passwords as secure as text-based passwords?"; "What are the major design and implementation issues for graphical passwords?" This survey will be useful for information security researchers and practitioners who are interested in finding an alternative to text-based authentication methods
---
paper_title: Analyzing User Choice in Graphical Passwords

paper_content:

In ubiquitous textual password schemes, users choose passwords that contain predictable characteristics that are roughly equated with what users flnd easy to recall. This motivates us to examine user choice in graphical passwords to determine whether predictable characteristics exist that may reduce the entropy of the password space. We present an informal user study of the scheme proposed by Jermyn et al. (1999), and the results, both in context of the study’s goals and a separate analysis of the results performed at a later date. Our results support that user drawings contain the predictable characteristics relating to symmetry, number of composite strokes, and centering within the grid. Our results also highlight a usability challenge with the DAS scheme.
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paper_title: PassPoints: Design and longitudinal evaluation of a graphical password system

paper_content:

Computer security depends largely on passwords to authenticate human users. However, users have difficulty remembering passwords over time if they choose a secure password, i.e. a password that is long and random. Therefore, they tend to choose short and insecure passwords. Graphical passwords, which consist of clicking on images rather than typing alphanumeric strings, may help to overcome the problem of creating secure and memorable passwords. In this paper we describe PassPoints, a new and more secure graphical password system. We report an empirical study comparing the use of PassPoints to alphanumeric passwords. Participants created and practiced either an alphanumeric or graphical password. The participants subsequently carried out three longitudinal trials to input their password over the course of 6 weeks. The results show that the graphical password users created a valid password with fewer difficulties than the alphanumeric users. However, the graphical users took longer and made more invalid password inputs than the alphanumeric users while practicing their passwords. In the longitudinal trials the two groups performed similarly on memory of their password, but the graphical group took more time to input a password.
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paper_title: Passshapes - utilizing stroke based authentication to increase password memorability

paper_content:

Authentication today mostly relies on passwords or personal identification numbers (PINs). Therefore the average user has to remember an increasing amount of PINs and passwords. Unfortunately, humans have limited capabilities for remembering abstract alphanumeric sequences. Thus, many people either forget them or use very simple ones, which implies several security risks. In this work, a novel authentication method called PassShapes is presented. In this system users authenticate themselves to a computing system by drawing simple geometric shapes constructed of an arbitrary combination of eight different strokes. We argue that using such shapes will allow more complex and thus more secure authentication tokens with a lower cognitive load and higher memorability. To prove these assumptions, two user studies have been conducted. The memorability evaluation showed that the PassShapes concept is able to increase the memorability when users can practice the PassShapes several times. This effect is even increasing over time. Additionally, a prototype was implemented to conduct a usability study. The results of both studies indicate that the PassShapes approach is able to provide a usable and memorable authentication method.
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paper_title: Graphical Dictionaries and the Memorable Space of Graphical Passwords

paper_content:

In commonplace textual password schemes, users choose passwords that are easy to recall. Since memorable passwords typically exhibit patterns, they are exploitable by brute-force password crackers using attack dictionaries. This leads us to ask what classes of graphical passwords users find memorable. We postulate one such class supported by a collection of cognitive studies on visual recall, which can be characterized as mirror symmetric (reflective) passwords. We assume that an attacker would put this class in an attack dictionary for graphical passwords and propose how an attacker might order such a dictionary. We extend the existing analysis of graphical passwords by analyzing the size of the mirror symmetric password space relative to the full password space of the graphical password scheme of Jermyn et al. (1999), and show it to be exponentially smaller (assuming appropriate axes of reflection). This reduction in size can be compensated for by longer passwords: the size of the space of mirror symmetric passwords of length about L + 5 exceeds that of the full password space for corresponding length L ≤ 14 on a 5 × 5 grid. This work could be used to help in formulating password rules for graphical password users and in creating proactive graphical password checkers.
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paper_title: On predictive models and user-drawn graphical passwords

paper_content:

In commonplace text-based password schemes, users typically choose passwords that are easy to recall, exhibit patterns, and are thus vulnerable to brute-force dictionary attacks. This leads us to ask whether other types of passwords (e.g., graphical) are also vulnerable to dictionary attack because of users tending to choose memorable passwords. We suggest a method to predict and model a number of such classes for systems where passwords are created solely from a user's memory. We hypothesize that these classes define weak password subspaces suitable for an attack dictionary. For user-drawn graphical passwords, we apply this method with cognitive studies on visual recall. These cognitive studies motivate us to define a set of password complexity factors (e.g., reflective symmetry and stroke count), which define a set of classes. To better understand the size of these classes and, thus, how weak the password subspaces they define might be, we use the “Draw-A-Secret” (DAS) graphical password scheme of Jermyn et al. [1999] as an example. We analyze the size of these classes for DAS under convenient parameter choices and show that they can be combined to define apparently popular subspaces that have bit sizes ranging from 31 to 41—a surprisingly small proportion of the full password space (58 bits). Our results quantitatively support suggestions that user-drawn graphical password systems employ measures, such as graphical password rules or guidelines and proactive password checking.
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paper_title: Towards secure design choices for implementing graphical passwords

paper_content:

We study the impact of selected parameters on the size of the password space for "Draw-A-Secret" (DAS) graphical passwords. We examine the role of and relationships between the number of composite strokes, grid dimensions, and password length in the DAS password space. We show that a very significant proportion of the DAS password space depends on the assumption that users will choose long passwords with many composite strokes. If users choose passwords having 4 or fewer strokes, with passwords of length 12 or less on a 5 /spl times/ 5 grid, instead of up to the maximum 12 possible strokes, the size of the DAS password space is reduced from 58 to 40 bits. Additionally, we found a similar reduction when users choose no strokes of length 1. To strengthen security, we propose a technique and describe a representative system that may gain up to 16 more bits of security with an expected negligible increase in input time. Our results can be directly applied to determine secure design choices, graphical password parameter guidelines, and in deciding which parameters deserve focus in graphical password user studies.
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paper_title: An enhanced drawing reproduction graphical password strategy

paper_content:

Passwords are used in the vast majority of computer and communication systems for authentlcation. The greater security and memorability of graphical passwords make them a possible alternative to traditional textual passwords. In this paper we propose a new graphical password scheme called YAGP, which is an extension of the Draw-A-Secret (DAS) scheme. The main difference between YAGP and DAS is soft matching. The concepts of the stroke-box, image-box, trend quadrant, and similarity are used to describe the images characteristics for soft matching. The reduction in strict user input rules in soft matching improves the usability and therefore creates a great advantage. The denser grid granubtrity enables users to design a longer password, enlarging the practical password space and enhancing security. Meanwhile, YAGP adopts a triple-register process to create multi-templates, increasing the accuracy and memorability of characteristics extraction. Experiments illustrate the effectiveness of YAGP.
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paper_title: Is a picture really worth a thousand words? Exploring the feasibility of graphical authentication systems

paper_content:

The weakness of knowledge-based authentication systems, such as passwords and Personal Identification Numbers (PINs), is well known, and reflects an uneasy compromise between security and human memory constraints. Research has been undertaken for some years now into the feasibility of graphical authentication mechanisms in the hope that these will provide a more secure and memorable alternative. The graphical approach substitutes the exact recall of alphanumeric codes with the recognition of previously learnt pictures, a skill at which humans are remarkably proficient. So far, little attention has been devoted to usability, and initial research has failed to conclusively establish significant memory improvement. This paper reports two user studies comparing several implementations of the graphical approach with PINs. Results demonstrate that pictures can be a solution to some problems relating to traditional knowledge-based authentication but that they are not a simple panacea, since a poor design can eliminate the picture superiority effect in memory. The paper concludes by discussing the potential of the graphical approach and providing guidelines for developers contemplating using these mechanisms.
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paper_title: Smudge Attacks on Smartphone Touch Screens

paper_content:

Touch screens are an increasingly common feature on personal computing devices, especially smartphones, where size and user interface advantages accrue from consolidating multiple hardware components (keyboard, number pad, etc.) into a single software definable user interface. Oily residues, or smudges, on the touch screen surface, are one side effect of touches from which frequently used patterns such as a graphical password might be inferred. ::: ::: In this paper we examine the feasibility of such smudge attacks on touch screens for smartphones, and focus our analysis on the Android password pattern. We first investigate the conditions (e.g., lighting and camera orientation) under which smudges are easily extracted. In the vast majority of settings, partial or complete patterns are easily retrieved. We also emulate usage situations that interfere with pattern identification, and show that pattern smudges continue to be recognizable. Finally, we provide a preliminary analysis of applying the information learned in a smudge attack to guessing an Android password pattern.
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paper_title: The Design and Analysis of Graphical Passwords

paper_content:

In this paper we propose and evaluate new graphical password schemes that exploit features of graphical input displays to achieve better security than text-based passwords. Graphical input devices enable the user to decouple the position of inputs from the temporal order in which those inputs occur, and we show that this decoupling can be used to generate password schemes with substantially larger (memorable) password spaces. In order to evaluate the security of one of our schemes, we devise a novel way to capture a subset of the "memorable" passwords that, we believe, is itself a contribution. In this work we are primarily motivated by devices such as personal digital assistants (PDAs) that offer graphical input capabilities via a stylus, and we describe our prototype implementation of one of our password schemes on such a PDA, namely the Palm PilotTM.
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paper_title: Graphical passwords & qualitative spatial relations

paper_content:

A potential drawback of graphical password schemes is that they are more vulnerable to shoulder surfing than conventional alphanumeric text passwords. We present a variation of the Draw-a-Secret scheme originally proposed by Jermyn et al [1] that is more resistant to shoulder surfing through the use of a qualitative mapping between user strokes and the password, and the use of dynamic grids to both obfuscate attributes of the user secret and encourage them to use different surface realizations of the secret. The use of qualitative spatial relations relaxes the tight constraints on the reconstruction of a secret; allowing a range of deviations from the original. We describe QDAS (Qualitative Draw-A-Secret), an initial implementation of this graphical password scheme, and the results of an empirical study in which we examined the memorability of secrets, and their susceptibility to shoulder-surfing attacks, for both Draw-A-Secret and QDAS.
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paper_title: The design and implementation of background Pass-Go scheme towards security threats

paper_content:

Currently, access to computer systems is often based on the use of alpha-numeric. The textual passwords or alpha-numeric passwords have been the basis of authentication systems for centuries. Similarly, it had also been the major attraction for crackers and attackers. However, users tend to face difficulty in remembering a password that is considered as secured password because this type of secured password usually has long string of characters and they appear randomly [14]. Hence, most users tend to create simple, short and insecure passwords. As a consequence, most of the time, the usability level of passwords has not achieved an optimum for a secured password [14]. In order to solve this problem, a new password scheme had been invented, known as Graphical Password System (GPS). Graphical password is an alternative mean of authentication for login intended to be used in place of conventional password; it utilizes images instead of text. In this paper, we discuss the design and intention of our proposed scheme, called Background Pass-Go (BPG). BPG is an improved version of Pass-Go, as it keeps most of the advantages of Pass-Go and achieves better usability. We had analyzed the BPG scheme in terms of 1) how BPG is able to improve other schemes of GPS especially in Pass-Go, 2) how BPG acts as a solution to different types of threats to networked computer systems. We had verified that BPG manages to overcome the shortage of other GPS schemes. Moreover, the BPG also manages to address most of the security threats for the network security system.
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paper_title: Pass-Go: A Proposal to Improve the Usability of Graphical Passwords

paper_content:

Inspired by an old Chinese game, Go, we have designed a new graphical password scheme, Pass-Go, in which a user selects intersections on a grid as a way to input a password. While offering an extremely large full password space (256 bits for the most basic scheme), our scheme provides acceptable usability, as empirically demonstrated by, to the best of our knowledge, the largest user study (167 subjects involved) on graphical passwords, conducted in the fall semester of 2005 in two university classes. Our scheme supports most application environments and input devices, rather than being limited to small mobile devices (PDAs), and can be used to derive cryptographic keys. We study the memorable password space and show the potential power of this scheme by exploring further improvements and variation mechanisms.
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paper_title: Multi-grid background Pass-Go

paper_content:

Computer security depends largely on passwords to authenticate the human user for access to secure systems. Remembering the password they have chosen is a frequent problem for all users. As a result, they tend to choose short and insecure passwords as compared to secure passwords which usually consist of a long mixture of random alphanumeric and non-alphanumeric characters. Thus, the tendency of choosing insecure passwords has brought up many security problems. Graphical password is an alternative to replace alphanumeric password in which users only have to click on the images in order to authenticate themselves rather than typing alphanumeric strings. The main objectives of this paper are to present a classification of graphical passwords system (GPS) and identify its future research area. In this paper, we attempt to identify a number of threats to the networked computer systems, focus on the research of graphical password system (GPS) and analysis on some aspects of GPS; 1) how each GPS algorithm works, 2) the advantages and disadvantages of each GPS algorithm, 3) how each GPS algorithm is able to address solutions to the threats. Besides, the paper also concentrates on the design and the implication of a proposed prototype, namely Multi-Grid Background Pass-Go (MGBPG) which is targeted to be its strength and the winning edge over other graphical password systems. The preliminary result and analysis of the proposed prototype is then presented by comparing it on its role in addressing the drawbacks of current existing GPS and several security attacks. Finally, we highlight a few aspects, which need to be improved in the future to overcome the deficiencies of previous GPS methods that have been invented.
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paper_title: YAGP: Yet Another Graphical Password Strategy

paper_content:

Alphanumeric passwords are widely used in computer and network authentication to protect users' privacy. However, it is well known that long, text-based passwords are hard for people to remember, while shorter ones are susceptible to attack. Graphical password is a promising solution to this problem. Draw-A-Secret (DAS) is a typical implementation based on the user drawing on a grid canvas. Currently, too many constraints result in reduction in user experience and prevent its popularity. A novel graphical password strategy Yet Another Graphical Password (YAGP) inspired by DAS is proposed in this paper. The proposal has the advantages of free drawing positions, strong shoulder surfing resistance and large password space. Experiments illustrate the effectiveness of YAGP.
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paper_title: Analyzing User Choice in Graphical Passwords

paper_content:

In ubiquitous textual password schemes, users choose passwords that contain predictable characteristics that are roughly equated with what users flnd easy to recall. This motivates us to examine user choice in graphical passwords to determine whether predictable characteristics exist that may reduce the entropy of the password space. We present an informal user study of the scheme proposed by Jermyn et al. (1999), and the results, both in context of the study’s goals and a separate analysis of the results performed at a later date. Our results support that user drawings contain the predictable characteristics relating to symmetry, number of composite strokes, and centering within the grid. Our results also highlight a usability challenge with the DAS scheme.
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paper_title: Do background images improve "draw a secret" graphical passwords?

paper_content:

Draw a secret (DAS) is a representative graphical password scheme. Rigorous theoretical analysis suggests that DAS supports an overall password space larger than that of the ubiquitous textual password scheme. However, recent research suggests that DAS users tend to choose weak passwords, and their choices would render this theoretically sound scheme less secure in real life. In this paper we investigate the novel idea of introducing background images to the DAS scheme, where users were initially supposed to draw passwords on a blank canvas overlaid with a grid. Encouraging results from our two user studies have shown that people aided with background images tended to set significantly more complicated passwords than their counterparts using the original scheme. The background images also reduced other predictable characteristics in DAS passwords such as symmetry and centering within the drawing grid, further improving the strength of the passwords. We estimate that the average strength of successfully recalled passwords in the enhanced scheme was increased over those created using the original scheme by more than 10 bits. Moreover, a positive effect was observed with respect to the memorability of the more complex passwords encouraged by the background images.
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paper_title: Your Memory: How It Works and How to Improve It

paper_content:

The word mnemonic (pronounced “ne MON ik”) is briefly defined as “aiding the memory.” It is derived from Mnemosyne, the name of the ancient Greek goddess of memory. “Mnemonics” refers in general to methods for improving memory; a mnemonic technique is any technique that aids the memory. Most researchers, however, define mnemonics more narrowly as being what most people consider to be rather unusual, artificial memory aids.
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paper_title: Persuasive Cued Click-Points: Design, Implementation, and Evaluation of a Knowledge-Based Authentication Mechanism

paper_content:

This paper presents an integrated evaluation of the Persuasive Cued Click-Points graphical password scheme, including usability and security evaluations, and implementation considerations. An important usability goal for knowledge-based authentication systems is to support users in selecting passwords of higher security, in the sense of being from an expanded effective security space. We use persuasion to influence user choice in click-based graphical passwords, encouraging users to select more random, and hence more difficult to guess, click-points.
---
paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: Graphical Password Authentication using Cued Click Points

paper_content:

With the rapid use of computers, the security of passwords is must where privacy is important. For password protection various techniques are available. The main issues of knowledge based authentication, usually text based passwords, are well known. Users tend to choose passwords they can easily remember and hence can also be guessed by the hacker. To avoid the limitation of textual passwords, this paper focuses on the implementation of a Graphical Password Authentication System using cued click points based on the integrated evaluation of the cued click points. Click cued points (CCP) is a click-based graphical password scheme. Users click on one point per image for a sequence of images. The next image is based on the previous click-point. Users prefer CCP over Passpoints because selecting and remembering only one point per image is less secure, than having each image being triggered by the user’s memory as to where the corresponding point was located. CCP also provides greater security than PassPoints because the number of images increases the workload for attackers.
---
paper_title: A Novel Cued-recall Graphical Password Scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own disadvantages. For example, cued-recall graphical password schemes are vulnerable to shoulder-surfing and cannot prevent intersection analysis attack. A novel cued-recall graphical password scheme CBFG (Click Buttons according to Figures in Grids) is proposed in this paper. Inheriting the way of setting password in traditional cued-recall scheme, this scheme is also added the ideology of image identification. CBFG helps users tend to set their passwords more complex. Simultaneously, it has the capability against shoulder surfing attack and intersection analysis attack. Experiments illustrate that CBFG has better performance in usability, especially in security.
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paper_title: Influencing users towards better passwords: persuasive cued click-points

paper_content:

Usable security has unique usability challenges because the need for security often means that standard human-computer-interaction approaches cannot be directly applied. An important usability goal for authentication systems is to support users in selecting better passwords, thus increasing security by expanding the effective password space. In click-based graphical passwords, poorly chosen passwords lead to the emergence of hotspots -- portions of the image where users are more likely to select click-points, allowing attackers to mount more successful dictionary attacks. We use persuasion to influence user choice in click-based graphical passwords, encouraging users to select more random, and hence more secure, click-points. Our approach is to introduce persuasion to the Cued Click-Points graphical password scheme (Chiasson, van Oorschot, Biddle, 2007). Our resulting scheme significantly reduces hotspots while still maintaining its usability.
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paper_title: Graphical passwords: a survey

paper_content:

The most common computer authentication method is to use alphanumerical usernames and passwords. This method has been shown to have significant drawbacks. For example, users tend to pick passwords that can be easily guessed. On the other hand, if a password is hard to guess, then it is often hard to remember. To address this problem, some researchers have developed authentication methods that use pictures as passwords. In this paper, we conduct a comprehensive survey of the existing graphical password techniques. We classify these techniques into two categories: recognition-based and recall-based approaches. We discuss the strengths and limitations of each method and point out the future research directions in this area. We also try to answer two important questions: "Are graphical passwords as secure as text-based passwords?"; "What are the major design and implementation issues for graphical passwords?" This survey will be useful for information security researchers and practitioners who are interested in finding an alternative to text-based authentication methods
---
paper_title: PassPoints: Design and longitudinal evaluation of a graphical password system

paper_content:

Computer security depends largely on passwords to authenticate human users. However, users have difficulty remembering passwords over time if they choose a secure password, i.e. a password that is long and random. Therefore, they tend to choose short and insecure passwords. Graphical passwords, which consist of clicking on images rather than typing alphanumeric strings, may help to overcome the problem of creating secure and memorable passwords. In this paper we describe PassPoints, a new and more secure graphical password system. We report an empirical study comparing the use of PassPoints to alphanumeric passwords. Participants created and practiced either an alphanumeric or graphical password. The participants subsequently carried out three longitudinal trials to input their password over the course of 6 weeks. The results show that the graphical password users created a valid password with fewer difficulties than the alphanumeric users. However, the graphical users took longer and made more invalid password inputs than the alphanumeric users while practicing their passwords. In the longitudinal trials the two groups performed similarly on memory of their password, but the graphical group took more time to input a password.
---
paper_title: Analysis and Evaluation of the ColorLogin Graphical Password Scheme

paper_content:

It is believed that graphical passwords are more memorable than traditional textual passwords, but usually seen as complex and time-consuming for users. Furthermore, most of the existing graphical password schemes are vulnerable to spyware and shoulder surfing. ColorLogin uses color, a method not previously considered, to decrease login time. Multiple colors are used to confuse the peepers, while not burdening the legitimate users. Meanwhile, the scheme is resistant to shoulder surfing and intersection attack to a certain extent. This paper analyzes and evaluates the ColorLogin scheme using some experiments.
---
paper_title: Towards Usable Solutions to Graphical Password Hotspot Problem

paper_content:

Click based graphical passwords that use background images suffer from hot-spot problem. Previous graphical password schemes based on recognition of images do not have a sufficiently large password space suited for most Internet applications. In this paper, we propose two novel graphical password methods based on recognition of icons to solve the hotspot problem without decreasing the password space. The experiment we have conducted that compares the security and usability of proposed methods with earlier work (i.e. Passpoints) shows that hotspot problem can be eliminated if a small increase in password entrance and confirmation times is tolerable.
---
paper_title: Is a picture really worth a thousand words? Exploring the feasibility of graphical authentication systems

paper_content:

The weakness of knowledge-based authentication systems, such as passwords and Personal Identification Numbers (PINs), is well known, and reflects an uneasy compromise between security and human memory constraints. Research has been undertaken for some years now into the feasibility of graphical authentication mechanisms in the hope that these will provide a more secure and memorable alternative. The graphical approach substitutes the exact recall of alphanumeric codes with the recognition of previously learnt pictures, a skill at which humans are remarkably proficient. So far, little attention has been devoted to usability, and initial research has failed to conclusively establish significant memory improvement. This paper reports two user studies comparing several implementations of the graphical approach with PINs. Results demonstrate that pictures can be a solution to some problems relating to traditional knowledge-based authentication but that they are not a simple panacea, since a poor design can eliminate the picture superiority effect in memory. The paper concludes by discussing the potential of the graphical approach and providing guidelines for developers contemplating using these mechanisms.
---
paper_title: Design and evaluation of a shoulder-surfing resistant graphical password scheme

paper_content:

When users input their passwords in a public place, they may be at risk of attackers stealing their password. An attacker can capture a password by direct observation or by recording the individual's authentication session. This is referred to as shoulder-surfing and is a known risk, of special concern when authenticating in public places. Until recently, the only defense against shoulder-surfing has been vigilance on the part of the user. This paper reports on the design and evaluation of a game-like graphical method of authentication that is resistant to shoulder-surfing. The Convex Hull Click (CHC) scheme allows a user to prove knowledge of the graphical password safely in an insecure location because users never have to click directly on their password images. Usability testing of the CHC scheme showed that novice users were able to enter their graphical password accurately and to remember it over time. However, the protection against shoulder-surfing comes at the price of longer time to carry out the authentication.
---
paper_title: Use Your Illusion: secure authentication usable anywhere

paper_content:

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. Using low-fidelity tests to aid in the design, we implement prototypes of Use Your Illusion as i) an Ajax-based web service and ii) on Nokia N70 cellular phones. We conduct a between-subjects usability study of the cellular phone prototype with a total of 99 participants in two experiments. We demonstrate that, regardless of their age or gender, users are very skilled at recognizing degraded versions of self-chosen images, even on small displays and after time periods of one month. Our results indicate that graphical passwords with distorted images can achieve equivalent error rates to those using traditional images, but only when the original image is known.
---
paper_title: Are Passfaces 1 More Usable Than Passwords? A Field Trial Investigation

paper_content:

The proliferation of technology requiring user authentication has increased the number of passwords which users have to remember, creating a significant usability problem. This paper reports a usability comparison between a new mechanism for user authentication — Passfaces — and passwords, with 34 student participants in a 3-month field trial. Fewer login errors were made with Passfaces, even when periods between logins were long. On the computer facilities regularly chosen by participants to log in, Passfaces took a long time to execute. Participants consequently started their work later when using Passfaces than when using passwords, and logged into the system less often. The results emphasise the importance of evaluating the usability of security mechanisms in field trials.
---
paper_title: On User Choice in Graphical Password Schemes

paper_content:

Graphical password schemes have been proposed as an alternative to text passwords in applications that support graphics and mouse or stylus entry. In this paper we detail what is, to our knowledge, the largest published empirical evaluation of the effects of user choice on the security of graphical password schemes. We show that permitting user selection of passwords in two graphical password schemes, one based directly on an existing commercial product, can yield passwords with entropy far below the theoretical optimum and, in some cases, that are highly correlated with the race or gender of the user. For one scheme, this effect is so dramatic so as to render the scheme insecure. A conclusion of our work is that graphical password schemes of the type we study may generally require a different posture toward password selection than text passwords, where selection by the user remains the norm today.
---
paper_title: Cognitive authentication schemes safe against spyware

paper_content:

Can we secure user authentication against eavesdropping adversaries, relying on human cognitive functions alone, unassisted by any external computational device? To accomplish this goal, we propose challenge response protocols that rely on a shared secret set of pictures. Under the considered brute-force attack the protocols are safe against eavesdropping, in that a modestly powered adversary who fully records a series of successful interactions cannot compute the user's secret. Moreover, the protocols can be tuned to any desired level of security against random guessing, where security can be traded-off with authentication time. The proposed protocols have two drawbacks: First, training is required to familiarize the user with the secret set of pictures. Second, depending on the level of security required, entry time can be significantly longer than with alternative methods. We describe user studies showing that people can use these protocols successfully, and quantify the time it takes for training and for successful authentication. We show evidence that the secret can be maintained for a long time (up to a year) with relatively low loss.
---
paper_title: Awase-E: Image-Based Authentication for Mobile Phones Using User’s Favorite Images

paper_content:

There is a trade-off between security and usability in user authentication for mobile phones. Since such devices have a poor input interfaces, 4-digit number passwords are widely used at present. Therefore, a more secure and user friendly authentication is needed. This paper proposes a novel authentication method called “Awase-E”. The system uses image passwords. It, moreover, integrates image registration and notification interfaces. Image registration enables users to use their favorite image instead of a text password. Notification gives users a trigger to take action against a threat when it happens. Awase-E is implemented so that it has a higher usability even when it is used through a mobile phone.
---
paper_title: Action-based graphical password: “Click-a-Secret”

paper_content:

This paper relates to a novel graphical system named “Click-a-Secret” that allows entering a secret through interactions with an image. Seamless modifications of the image will create a new image and derive corresponding secret. In this article, we will focus on access control related applications. However, other usages are possible in various cryptographic systems (e.g.: secret key to encrypt data, etc.). It is well known that humans use long-term memory for storing pictures therefore leading to better recall of images compared to text. This leads to improved memorization of graphical passwords.
---
paper_title: S3PAS: A Scalable Shoulder-Surfing Resistant Textual-Graphical Password Authentication Scheme

paper_content:

The vulnerabilities of the textual password have been well known. Users tend to pick short passwords or passwords that are easy to remember, which makes the passwords vulnerable for attackers to break. Furthermore, textual password is vulnerable to shoulder-surfing, hidden-camera and spyware attacks. Graphical password schemes have been proposed as a possible alternative to text-based scheme. However, they are mostly vulnerable to shoulder-surfing. In this paper, we propose a Scalable Shoulder-Surfing Resistant Textual-Graphical Password Authentication Scheme (S3PAS). S3PAS seamlessly integrates both graphical and textual password schemes and provides nearly perfect resistant to shoulder-surfing, hidden-camera and spyware attacks. It can replace or coexist with conventional textual password systems without changing existing user password profiles. Moreover, it is immune to brute-force attacks through dynamic and volatile session passwords. S3PAS shows significant potential bridging the gap between conventional textual password and graphical password. Further enhancements of S3PAS scheme are proposed and briefly discussed. Theoretical analysis of the security level using S3PAS is also investigated.
---
paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: A Novel Cued-recall Graphical Password Scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own disadvantages. For example, cued-recall graphical password schemes are vulnerable to shoulder-surfing and cannot prevent intersection analysis attack. A novel cued-recall graphical password scheme CBFG (Click Buttons according to Figures in Grids) is proposed in this paper. Inheriting the way of setting password in traditional cued-recall scheme, this scheme is also added the ideology of image identification. CBFG helps users tend to set their passwords more complex. Simultaneously, it has the capability against shoulder surfing attack and intersection analysis attack. Experiments illustrate that CBFG has better performance in usability, especially in security.
---
paper_title: A New Graphical Password Scheme Resistant to Shoulder-Surfing

paper_content:

Shoulder-surfing is a known risk where an attacker can capture a password by direct observation or by recording the authentication session. Due to the visual interface, this problem has become exacerbated in graphical passwords. There have been some graphical schemes resistant or immune to shoulder-surfing, but they have significant usability drawbacks, usually in the time and effort to log in. In this paper, we propose and evaluate a new shoulder-surfing resistant scheme which has a desirable usability for PDAs. Our inspiration comes from the drawing input method in DAS and the association mnemonics in Story for sequence retrieval. The new scheme requires users to draw a curve across their password images orderly rather than click directly on them. The drawing input trick along with the complementary measures, such as erasing the drawing trace, displaying degraded images, and starting and ending with randomly designated images provide a good resistance to shoulder-surfing. A preliminary user study showed that users were able to enter their passwords accurately and to remember them over time.
---
paper_title: Evaluating the usability and security of a graphical one-time PIN system

paper_content:

Traditional Personal Identification Numbers (PINs) are widely used, but the attacks in which they are captured have been increasing. One-time PINs offer better security, but potentially create greater workload for users. In this paper, we present an independent evaluation of a commercial system that makes PINs more resistant to observation attacks by using graphical passwords on a grid to generate a one-time PIN. 83 participants were asked to register with the system and log in at varying intervals. The successful login rate was approximately 91% after 3--4 days, and 97% after 9--10 days. Twenty five participants were retested after two years, and 27% of those were able to recall their pattern. We recorded 17 instances of failed attempts, and found that even though participants recalled the general shape of the pass-pattern in 13 of these instances, they could not recall its detailed location or sequence of cells. We conclude that GrIDsure is usable if people have one pass-pattern, but the level of security will depend on the context of use (it will work best in scenarios where repeated observations of transactions are unlikely), and the instructions given to users (without guidance, they are likely to chose from a small subset of the possible patterns which are easily guessed).
---
paper_title: A Hybrid Password Authentication Scheme Based on Shape and Text

paper_content:

Text-based password authentication scheme tends to be more vulnerable to attacks such as shoulder surfing or a hidden camera. To overcome the vulnerabilities of traditional methods, visual or graphical password schemes have been developed as possible alternative solutions to text-based password schemes. Since it also has some drawbacks to simply adopt graphical password authentication, schemes using graphic and text have been developed. In this paper, a hybrid password authentication scheme based on shapes and texts is proposed. Shapes of strokes are used in the grid as the original passwords and users can log in with textual passwords via traditional input device. The method provides strong resistance to shoulder surfing or a hidden camera。Moreover, the scheme has high scalability and flexibility to enhance the authentication process security. The analysis of the security level of this approach is also discussed.
---
paper_title: Exploration of a hand-based graphical password scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own problems about memorability. Biometrics schemes are not widely adopted though they need no remembrance and provide the highest level of security, owing to their great cost both in device and time. In this paper, we explore the feasibility of introducing hand-based biometrics into the realm of graphical passwords with a simplified scheme named PassHands. PassHands has similar authentication form with Passfaces and has the advantages of unnecessary to remember the password and unpredictable of user choice. Some primary experiments are conducted and the results illustrate the performance of PassHands.
---
paper_title: Graphical passwords: a survey

paper_content:

The most common computer authentication method is to use alphanumerical usernames and passwords. This method has been shown to have significant drawbacks. For example, users tend to pick passwords that can be easily guessed. On the other hand, if a password is hard to guess, then it is often hard to remember. To address this problem, some researchers have developed authentication methods that use pictures as passwords. In this paper, we conduct a comprehensive survey of the existing graphical password techniques. We classify these techniques into two categories: recognition-based and recall-based approaches. We discuss the strengths and limitations of each method and point out the future research directions in this area. We also try to answer two important questions: "Are graphical passwords as secure as text-based passwords?"; "What are the major design and implementation issues for graphical passwords?" This survey will be useful for information security researchers and practitioners who are interested in finding an alternative to text-based authentication methods
---
paper_title: Securing passwords against dictionary attacks

paper_content:

The use of passwords is a major point of vulnerability in computer security, as passwords are often easy to guess by automated programs running dictionary attacks. Passwords remain the most widely used authentication method despite their well-known security weaknesses. User authentication is clearly a practical problem. From the perspective of a service provider this problem needs to be solved within real-world constraints such as the available hardware and software infrastructures. From a user's perspective user-friendliness is a key requirement.In this paper we suggest a novel authentication scheme that preserves the advantages of conventional password authentication, while simultaneously raising the costs of online dictionary attacks by orders of magnitude. The proposed scheme is easy to implement and overcomes some of the difficulties of previously suggested methods of improving the security of user authentication schemes.Our key idea is to efficiently combine traditional password authentication with a challenge that is very easy to answer by human users, but is (almost) infeasible for automated programs attempting to run dictionary attacks. This is done without affecting the usability of the system. The proposed scheme also provides better protection against denial of service attacks against user accounts.
---
paper_title: Purely Automated Attacks on PassPoints-Style Graphical Passwords

paper_content:

We introduce and evaluate various methods for purely automated attacks against PassPoints-style graphical passwords. For generating these attacks, we introduce a graph-based algorithm to efficiently create dictionaries based on heuristics such as click-order patterns (e.g., five points all along a line). Some of our methods combine click-order heuristics with focus-of-attention scan-paths generated from a computational model of visual attention, yielding significantly better automated attacks than previous work. One resulting automated attack finds 7%-16% of passwords for two representative images using dictionaries of approximately 226 entries (where the full password space is 243). Relaxing click-order patterns substantially increased the attack efficacy albeit with larger dictionaries of approximately 235 entries, allowing attacks that guessed 48%-54% of passwords (compared to previous results of 1% and 9% on the same dataset for two images with 235 guesses). These latter attacks are independent of focus-of-attention models, and are based on image-independent guessing patterns. Our results show that automated attacks, which are easier to arrange than human-seeded attacks and are more scalable to systems that use multiple images, require serious consideration when deploying basic PassPoints-style graphical passwords.
---
paper_title: Graphical Dictionaries and the Memorable Space of Graphical Passwords

paper_content:

In commonplace textual password schemes, users choose passwords that are easy to recall. Since memorable passwords typically exhibit patterns, they are exploitable by brute-force password crackers using attack dictionaries. This leads us to ask what classes of graphical passwords users find memorable. We postulate one such class supported by a collection of cognitive studies on visual recall, which can be characterized as mirror symmetric (reflective) passwords. We assume that an attacker would put this class in an attack dictionary for graphical passwords and propose how an attacker might order such a dictionary. We extend the existing analysis of graphical passwords by analyzing the size of the mirror symmetric password space relative to the full password space of the graphical password scheme of Jermyn et al. (1999), and show it to be exponentially smaller (assuming appropriate axes of reflection). This reduction in size can be compensated for by longer passwords: the size of the space of mirror symmetric passwords of length about L + 5 exceeds that of the full password space for corresponding length L ≤ 14 on a 5 × 5 grid. This work could be used to help in formulating password rules for graphical password users and in creating proactive graphical password checkers.
---
paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: Analyzing User Choice in Graphical Passwords

paper_content:

In ubiquitous textual password schemes, users choose passwords that contain predictable characteristics that are roughly equated with what users flnd easy to recall. This motivates us to examine user choice in graphical passwords to determine whether predictable characteristics exist that may reduce the entropy of the password space. We present an informal user study of the scheme proposed by Jermyn et al. (1999), and the results, both in context of the study’s goals and a separate analysis of the results performed at a later date. Our results support that user drawings contain the predictable characteristics relating to symmetry, number of composite strokes, and centering within the grid. Our results also highlight a usability challenge with the DAS scheme.
---
paper_title: Modeling user choice in the PassPoints graphical password scheme

paper_content:

We develop a model to identify the most likely regions for users to click in order to create graphical passwords in the PassPoints system. A PassPoints password is a sequence of points, chosen by a user in an image that is displayed on the screen. Our model predicts probabilities of likely click points; this enables us to predict the entropy of a click point in a graphical password for a given image. The model allows us to evaluate automatically whether a given image is well suited for the PassPoints system, and to analyze possible dictionary attacks against the system. We compare the predictions provided by our model to results of experiments involving human users. At this stage, our model and the experiments are small and limited; but they show that user choice can be modeled and that expansions of the model and the experiments are a promising direction of research.
---
paper_title: On User Choice in Graphical Password Schemes

paper_content:

Graphical password schemes have been proposed as an alternative to text passwords in applications that support graphics and mouse or stylus entry. In this paper we detail what is, to our knowledge, the largest published empirical evaluation of the effects of user choice on the security of graphical password schemes. We show that permitting user selection of passwords in two graphical password schemes, one based directly on an existing commercial product, can yield passwords with entropy far below the theoretical optimum and, in some cases, that are highly correlated with the race or gender of the user. For one scheme, this effect is so dramatic so as to render the scheme insecure. A conclusion of our work is that graphical password schemes of the type we study may generally require a different posture toward password selection than text passwords, where selection by the user remains the norm today.
---
paper_title: A Novel Cued-recall Graphical Password Scheme

paper_content:

Graphical passwords have been proposed as an alternative to alphanumeric passwords with their advantages in usability and security. However, most of these alternate schemes have their own disadvantages. For example, cued-recall graphical password schemes are vulnerable to shoulder-surfing and cannot prevent intersection analysis attack. A novel cued-recall graphical password scheme CBFG (Click Buttons according to Figures in Grids) is proposed in this paper. Inheriting the way of setting password in traditional cued-recall scheme, this scheme is also added the ideology of image identification. CBFG helps users tend to set their passwords more complex. Simultaneously, it has the capability against shoulder surfing attack and intersection analysis attack. Experiments illustrate that CBFG has better performance in usability, especially in security.
---
paper_title: A New Graphical Password Scheme Resistant to Shoulder-Surfing

paper_content:

Shoulder-surfing is a known risk where an attacker can capture a password by direct observation or by recording the authentication session. Due to the visual interface, this problem has become exacerbated in graphical passwords. There have been some graphical schemes resistant or immune to shoulder-surfing, but they have significant usability drawbacks, usually in the time and effort to log in. In this paper, we propose and evaluate a new shoulder-surfing resistant scheme which has a desirable usability for PDAs. Our inspiration comes from the drawing input method in DAS and the association mnemonics in Story for sequence retrieval. The new scheme requires users to draw a curve across their password images orderly rather than click directly on them. The drawing input trick along with the complementary measures, such as erasing the drawing trace, displaying degraded images, and starting and ending with randomly designated images provide a good resistance to shoulder-surfing. A preliminary user study showed that users were able to enter their passwords accurately and to remember them over time.
---
paper_title: Evaluating the usability and security of a graphical one-time PIN system

paper_content:

Traditional Personal Identification Numbers (PINs) are widely used, but the attacks in which they are captured have been increasing. One-time PINs offer better security, but potentially create greater workload for users. In this paper, we present an independent evaluation of a commercial system that makes PINs more resistant to observation attacks by using graphical passwords on a grid to generate a one-time PIN. 83 participants were asked to register with the system and log in at varying intervals. The successful login rate was approximately 91% after 3--4 days, and 97% after 9--10 days. Twenty five participants were retested after two years, and 27% of those were able to recall their pattern. We recorded 17 instances of failed attempts, and found that even though participants recalled the general shape of the pass-pattern in 13 of these instances, they could not recall its detailed location or sequence of cells. We conclude that GrIDsure is usable if people have one pass-pattern, but the level of security will depend on the context of use (it will work best in scenarios where repeated observations of transactions are unlikely), and the instructions given to users (without guidance, they are likely to chose from a small subset of the possible patterns which are easily guessed).
---
paper_title: A comparison of perceived and real shoulder-surfing risks between alphanumeric and graphical passwords

paper_content:

Previous research has found graphical passwords to be more memorable than non-dictionary or "strong" alphanumeric passwords. Participants in a prior study expressed concerns that this increase in memorability could also lead to an increased susceptibility of graphical passwords to shoulder-surfing. This appears to be yet another example of the classic trade-off between usability and security for authentication systems. This paper explores whether graphical passwords' increased memorability necessarily leads to risks of shoulder-surfing. To date, there are no studies examining the vulnerability of graphical versus alphanumeric passwords to shoulder-surfing.This paper examines the real and perceived vulnerability to shoulder-surfing of two configurations of a graphical password, Passfaces™[30], compared to non-dictionary and dictionary passwords. A laboratory experiment with 20 participants asked them to try to shoulder surf the two configurations of Passfaces™ (mouse versus keyboard data entry) and strong and weak passwords. Data gathered included the vulnerability of the four authentication system configurations to shoulder-surfing and study participants' perceptions concerning the same vulnerability. An analysis of these data compared the relative vulnerability of each of the four configurations to shoulder-surfing and also compared study participants' real and perceived success in shoulder-surfing each of the configurations. Further analysis examined the relationship between study participants' real and perceived success in shoulder-surfing and determined whether there were significant differences in the vulnerability of the four authentication configurations to shoulder-surfing.Findings indicate that configuring data entry for Passfaces™ through a keyboard is the most effective deterrent to shoulder-surfing in a laboratory setting and the participants' perceptions were consistent with that result. While study participants believed that Passfaces™ with mouse data entry would be most vulnerable to shoulder-surfing attacks, the empirical results found that strong passwords were actually more vulnerable.
---
paper_title: Design and evaluation of a shoulder-surfing resistant graphical password scheme

paper_content:

When users input their passwords in a public place, they may be at risk of attackers stealing their password. An attacker can capture a password by direct observation or by recording the individual's authentication session. This is referred to as shoulder-surfing and is a known risk, of special concern when authenticating in public places. Until recently, the only defense against shoulder-surfing has been vigilance on the part of the user. This paper reports on the design and evaluation of a game-like graphical method of authentication that is resistant to shoulder-surfing. The Convex Hull Click (CHC) scheme allows a user to prove knowledge of the graphical password safely in an insecure location because users never have to click directly on their password images. Usability testing of the CHC scheme showed that novice users were able to enter their graphical password accurately and to remember it over time. However, the protection against shoulder-surfing comes at the price of longer time to carry out the authentication.
---
paper_title: Graphical passwords & qualitative spatial relations

paper_content:

A potential drawback of graphical password schemes is that they are more vulnerable to shoulder surfing than conventional alphanumeric text passwords. We present a variation of the Draw-a-Secret scheme originally proposed by Jermyn et al [1] that is more resistant to shoulder surfing through the use of a qualitative mapping between user strokes and the password, and the use of dynamic grids to both obfuscate attributes of the user secret and encourage them to use different surface realizations of the secret. The use of qualitative spatial relations relaxes the tight constraints on the reconstruction of a secret; allowing a range of deviations from the original. We describe QDAS (Qualitative Draw-A-Secret), an initial implementation of this graphical password scheme, and the results of an empirical study in which we examined the memorability of secrets, and their susceptibility to shoulder-surfing attacks, for both Draw-A-Secret and QDAS.
---
paper_title: A Hybrid Password Authentication Scheme Based on Shape and Text

paper_content:

Text-based password authentication scheme tends to be more vulnerable to attacks such as shoulder surfing or a hidden camera. To overcome the vulnerabilities of traditional methods, visual or graphical password schemes have been developed as possible alternative solutions to text-based password schemes. Since it also has some drawbacks to simply adopt graphical password authentication, schemes using graphic and text have been developed. In this paper, a hybrid password authentication scheme based on shapes and texts is proposed. Shapes of strokes are used in the grid as the original passwords and users can log in with textual passwords via traditional input device. The method provides strong resistance to shoulder surfing or a hidden camera。Moreover, the scheme has high scalability and flexibility to enhance the authentication process security. The analysis of the security level of this approach is also discussed.
---
paper_title: The urgency for effective user privacy-education to counter social engineering attacks on secure computer systems

paper_content:

Trusted people can fail to be trustworthy when it comes to protecting their aperture of access to secure computer systems due to inadequate education, negligence, and various social pressures. People are often the weakest link in an otherwise secure computer system and, consequently, are targeted for social engineering attacks. Social Engineering is a technique used by hackers or other attackers to gain access to information technology systems by getting the needed information (for example, a username and password) from a person rather than breaking into the system through electronic or algorithmic hacking methods. Such attacks can occur on both a physical and psychological level. The physical setting for these attacks occurs where a victim feels secure: often the workplace, the phone, the trash, and even on-line. Psychology is often used to create a rushed or officious ambiance that helps the social engineer to cajole information about accessing the system from an employee. Data privacy legislation in the United States and international countries that imposes privacy standards and fines for negligent or willful non-compliance increases the urgency to measure the trustworthiness of people and systems. One metric for determining compliance is to simulate, by audit, a social engineering attack upon an organization required to follow data privacy standards. Such an organization commits to protect the confidentiality of personal data with which it is entrusted. This paper presents the results of an approved social engineering audit made without notice within an organization where data security is a concern. Areas emphasized include experiences between the Social Engineer and the audited users, techniques used by the Social Engineer, and other findings from the audit. Possible steps to mitigate exposure to the dangers of Social Engineering through improved user education are reviewed.
---
paper_title: Graphical passwords: Learning from the first twelve years

paper_content:

Starting around 1999, a great many graphical password schemes have been proposed as alternatives to text-based password authentication. We provide a comprehensive overview of published research in the area, covering both usability and security aspects as well as system evaluation. The article first catalogues existing approaches, highlighting novel features of selected schemes and identifying key usability or security advantages. We then review usability requirements for knowledge-based authentication as they apply to graphical passwords, identify security threats that such systems must address and review known attacks, discuss methodological issues related to empirical evaluation, and identify areas for further research and improved methodology.
---
paper_title: A Small Subgroup Attack for Recovering Ephemeral Keys in Chang and Chang Password Key Exchange Protocol

paper_content:

Three-party authenticated key exchange protocol is an important cryptographic technique in the secure communication areas. Recently Chang and Chang proposed a novel three party simple key exchange protocol and claimed the protocol is secure, efficient and practical. Unless their claim, a key recovery attack is proposed on the above protocol by recovering the ephemeral keys. One way of recovering the ephemeral key is to solve the mathematical hard Discrete Logarithm Problem (DLP). The DLP is solved by using a popular Pohlig-Hellman method in the above key recovery attack. In the present study, a new method based on the small subgroup attack to solve the DLP is discussed to recover the ephemeral keys. Computation of DLP is carried out by two stages, such as the prior-computation and DLP computation. The prior-computation is performed on off-line and the DLP computation is performed on on-line. The method is analyzed on a comprehensive set of experiments and the ephemeral keys are recovered in reduced time. Also, the key recovery attack on Chang and Chang password key exchange protocol is implemented by using the new method to recover the ephemeral key.
---
paper_title: An Authentication and Key Agreement Scheme with Key Confirmation and Privacy-preservation for Multi-server Environments

paper_content:

In the internet environment, it is desirable for a user to login different servers by keying the same password and using the same smart card. This paper proposes an authentication and key agreement scheme with key confirmation for multi-server environments. Compared with the previous authentication and key agreement schemes for multi-server environments, the new scheme holds many merits. It satisfies the following properties: R1. Single registration; R2. User friendly; R3. Prevention of the replay, the password guessing without smart cards, the impersonation and the stolen-verifier attacks; R4. Resistance against server spoofing; R5. Mutual authentication; R6. Two-factor authentication; R7.Resistance against known-key attacks; R8. Perfect forward secrecy; R9. Scalability of login; R10. Anonymity of users.
---

Title: A Survey on the Use of Graphical Passwords in Security

Section 1: INTRODUCTION
Description 1: This section introduces the importance of authentication in information security, the drawbacks of traditional alphanumeric passwords, and the advantages of graphical passwords which use images to enhance memorability and security.

Section 2: LITERATURE REVIEW
Description 2: This section reviews existing studies on graphical passwords, focusing on specific schemes, security analyses, and prior surveys that laid the foundation for further research.

Section 3: CATEGORIZATION OF GRAPHICAL PASSWORDS
Description 3: This section categorizes graphical password schemes into four main categories: Drawmetric schemes, Locimetric schemes, Cognometric schemes, and Hybrid schemes, providing an overview and discussion of each category.

Section 4: Drawmetric Schemes
Description 4: This subsection provides an in-depth analysis of Drawmetric schemes, including various specific schemes, their development, strengths, and weaknesses.

Section 5: Locimetric Schemes
Description 5: This subsection explores Locimetric schemes, detailing their methodology, notable examples, and associated security concerns.

Section 6: Cognometric Schemes
Description 6: This subsection discusses Cognometric schemes, their reliance on image recognition for authentication, and the usability and security implications.

Section 7: Hybrid Schemes
Description 7: This subsection examines Hybrid schemes that combine elements from different types of schemes to enhance security and usability.

Section 8: ATTACK TYPES BASED ON PASSWORD SPACE
Description 8: This section introduces common attack methods like brute force and dictionary attacks and provides universal password space formulas for graphical password schemes.

Section 9: Brute Force Attack
Description 9: This subsection explains brute force attacks, their application to graphical passwords, and methods to resist these attacks by increasing password space.

Section 10: Dictionary Attack
Description 10: This subsection describes dictionary attacks, their implications for graphical passwords, and how user choice patterns can affect the efficacy of such attacks.

Section 11: ATTACK TYPES BASED ON PASSWORD CAPTURE
Description 11: This section discusses attacks based on capturing passwords, including shoulder surfing, intersection analysis, social engineering, and spyware attacks.

Section 12: Shoulder Surfing
Description 12: This subsection addresses the susceptibility of graphical passwords to shoulder surfing attacks and the schemes developed to resist such attacks.

Section 13: Intersection Analysis
Description 13: This subsection details intersection analysis attacks, particularly problematic for schemes using multiple image selections.

Section 14: Social Engineering
Description 14: This subsection explores social engineering attacks like tricking, phishing, and pharming targeting graphical passwords.

Section 15: Spyware Attack
Description 15: This subsection discusses the threat of spyware attacks, including keystroke-loggers, mouse-loggers, and screen-scrapers, and their impact on graphical password schemes.

Section 16: CONCLUSION AND RECOMMENDATION
Description 16: This section provides a summary of the survey, analyzing the strengths and weaknesses of graphical password schemes and offering recommendations for improving security and usability.