DOCSLIB.ORG

The Effect of Repeated Login Prompts on Phishing Susceptibility

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Effect of Repeated Login Prompts on Phishing Susceptibility The Effect of Repeated Login Prompts on Phishing Susceptibility Peter Snyder and Chris Kanich Mike K. Reiter Department of Computer Science Department of Computer Science University of Illinois at Chicago University of North Carolina at Chapel Hill fpsnyde2,[email protected] [email protected] Abstract 1 Introduction and Motivation Of all cybersecurity attacks, Phishing is perhaps most Background. Understanding the human aspects of phish- intimately tied to user decisions and behavior, rather than ing susceptibility is an important component in building technical weaknesses of the platform on which it is per- effective defenses. People type passwords so often that it petrated. Despite numerous studies both aimed at better is possible that this act makes each individual password understanding why and how people fall for phishing at- less safe from phishing attacks. tacks [3, 4] and new systems to detect the sites themselves Aim. This study investigates whether the act of re- and protect users [9], the problem continues, [6] and thus authenticating to password based login forms causes users fully understanding the causes and effects of the phe- to become less vigilant toward impostor sites, thus making nomenon is a crucial component of successful defenses. them more susceptible to phishing attacks. Our goal is to Fundamental to phishing as an attack is the user cre- determine whether users who type their passwords more dential, which is most often a password, also sometimes often are more susceptible to phishing than users who type accompanied by multi factor authentication credentials. their passwords less often. If our hypothesis is correct, Passwords have been the subject of intense investigation this result could lead to theoretically well grounded best along many dimensions; Bonneau et al. present a frame- practices regarding login session length limits and re- work for comparing passwords along with other authenti- authentication practices. cation schemes in [1]. One weakness of passwords they highlight is that the current one password per site ecosys- Method. We built a custom browser extension which tem has several downsides: it urges users to remember logs password entry events and has the capability of short- different passwords and greatly penalizes password re- ening session times for a treatment group of users. We use due to password database leaks or other brute force recruited subjects from our local campus population, and attacks on the simple passwords schemes people use to had them run the extension for two months. After this remember several passwords. time, we conducted a synthetic phishing attack on all re- Beyond the weaknesses listed in [1], another negative search subjects, followed by a debriefing. Our research aspect of password based authentication is the frequency protocol was approved by the University’s IRB. with which users are asked to re-authenticate to ALL sites, Results. We failed to reject the null hypothesis. We not just individual sites. In the Internet’s infancy, personal found that login frequency has no noticeable effect on computers were commonly shared among different users, phishing susceptibility. Our high phishing success rate of and software to enable efficient sharing via different pro- 39.3% was likely a leading factor in this result. files did not yet exist. Thus, automatically logging users out after some relatively short period of time, either due Conclusions. This study confirms prior research show- to memory limitations or security concerns, is the de facto ing exceedingly high phishing success rates. We also default security posture with respect to authentication ses- observed that recruiting in-person and campus-affiliated sions. In the present day however, modern software can users only greatly reduced our subject pool, and that easily support long lived session records, browsing often the extension based investigation method, while promis- takes place on single user devices like smarthpones, and ing, faces significant challenges itself due to deployed streamlined browser profiles make separating different extension-based malware defenses. user accounts easy even on shared devices. Thus, the 1 choice of a session length is purely a security decision. 2 Methodology Several services like Facebook and Google have adopted a strategy where sessions remain logged in for This work was carried out in five stages, starting with an indeterminately long amount of time.1 However, to the development of the software used to measure and our knowledge there is no scholarship or best practices manipulate the web browsing experience of the control document available which provides a breakdown of how group, and ending with informing the test participants successful this practice is, and it has not seen widespread about the experiment they participated in. This section adoption on the rest of the web. describes each of these five sections in chronological With respect to phishing defenses, this might indeed order. be a very good one: the longer a session remains in place on a given device, the less common the sight of the login 2.1 Web Browser Extension Development screen (or even any login screen across all sites) is to the individual user. If login screens are less common, Browser extensions are pieces of software that are in- we hypothesize that this will cause the user to be more stalled in commodity web browsers to measure or modify alert when logging in to services. While this may be the the user’s browsing experience. Though all recent ver- reasoning behind the long lived sessions used by large sions of popular web browsers support the ability to write Internet companies, being able to reproduce this effect and install extensions, we limited our study to people in open scholarship would be an important step towards using Firefox and Chrome. convincing more software authors and site owners to make Our study included two different extensions, one ver- these longer lived sessions the default. sion for the control group that only took measurements Specifically, financial services websites very often keep of the user’s browsing activities, and another version their session lengths limited to hours or even minutes. On for the experiment group that took the same measure- one hand, this choice is an entirely reasonable: an online ments but also modified the browser to induce the user banking session left logged in on a shared or stolen device to (re)authenticate with popular websites more frequently can cause immense damage for an individual. Conversely, than they normally would. Each of theses versions of the being prompted for these passwords continually has the extension are described in greater detail in the following very real potential to make those users more susceptible subsections. to phishing attacks. When considering the threat models When the user installed the extension in their browser, of phishing attacks and physical device takeover, the for- they were prompted to enter their email address. The mer can be perpetrated by anyone on the Internet rather extension then generated a random identifier for the user. than anyone with access to the device, potentially making At no point in the study did the researchers tie these two the phishing concern far greater than the session length identifiers together; we were never able to tie a person’s concern. random identifier with their email address. Each of these We claim that password re-entry frequency is not only a identifiers were used to identify users during different usability issue, but is also a security issue for all password parts of the study. Finally, on installing the extension based login systems. If users are conditioned to type users were randomly assigned to either the control or their passwords often, our hypothesis is that this action experiment group, with equal chance. habituates users to the act of password entry, which in Throughout the experiment the extensions reported turn causes the user to have more difficulty remaining statistics to a central recording server, which we main- vigilant to the threat of phishing. tained and used to gather data through the study. When This study was built to test that hypothesis. We devised the extension reported non-sensitive information to the a methodology which includes a control group whose recording server (such as how long a user has been par- login frequency is unmodified, and a treatment group ticipating in the study), the extension identified the user who have the length of their login session shortened, ne- by their email address. Likewise, whenever the exten- cessitating additional log-in which simulates sites with sion reported sensitive information to the server, the data short session timeouts. Unfortunately, we did not find was tied to the user’s random identifier. This allowed us statistical significance in our study, but were able to repli- to track which users were still participating in the study, cate important results in phishing susceptibility, and find without tying any sensitive information to the participant. new but unremarkable results related to well crafted spear phishing attacks. 2.1.1 Control Group Extension The control group version of the extension did not modify 1It remains to be seen whether such infrequent reauthentication might itself be harmful: if passwords are so rarely re-entered, the user the browsing experience at all, it only recorded informa- runs the risk of forgetting it simply because they never use it! tion about the user’s browsing activities. Each of these 2 data points is described below. figure1. When a user logs into one of these sites, the site User Participation: In order to determine which par- sets a cookie in the user’s browser. This cookie usually ticipants were staying active in the study (and to be able to lasts for a long time: days, weeks or months. The site remind participants if they were not staying active) the ex- uses this information to identify the user to the site, so tension reported the user’s email address to the recording that the site knows who the user is and does not ask the server once a day.
Load more

Recommended publications
  • Modern Password Security for System Designers What to Consider When Building a Password-Based Authentication System
    Modern password security for system designers What to consider when building a password-based authentication system By Ian Maddox and Kyle Moschetto, Google Cloud Solutions Architects This whitepaper describes and models modern password guidance and recommendations for the designers and engineers who create secure online applications. A related whitepaper, Password security ​ for users, offers guidance for end users. This whitepaper covers the wide range of options to consider ​ when building a password-based authentication system. It also establishes a set of user-focused recommendations for password policies and storage, including the balance of password strength and usability. The technology world has been trying to improve on the password since the early days of computing. Shared-knowledge authentication is problematic because information can fall into the wrong hands or be forgotten. The problem is magnified by systems that don't support real-world secure use cases and by the frequent decision of users to take shortcuts. According to a 2019 Yubico/Ponemon study, 69 percent of respondents admit to sharing passwords with ​ ​ their colleagues to access accounts. More than half of respondents (51 percent) reuse an average of five passwords across their business and personal accounts. Furthermore, two-factor authentication is not widely used, even though it adds protection beyond a username and password. Of the respondents, 67 percent don’t use any form of two-factor authentication in their personal life, and 55 percent don’t use it at work. Password systems often allow, or even encourage, users to use insecure passwords. Systems that allow only single-factor credentials and that implement ineffective security policies add to the problem.
    [Show full text]
  • Password Security Compliance
    Password Security Compliance Reduce risk and ensure compliance by managing password strength and policy. WHITE PAPER 1 PASSWORD SECURITY COMPLIANCE Reduce risk and ensure compliance by managing password strength and policy. Overview Passwords are a critical component of security. Passwords serve to protect user accounts; however, weak passwords may violate compliance standards, be reversed engineered back to plaintext and sold on the dark web, or result in a costly data breach if compromised. A periodic review of password rules is a vital component of your compliance and security strategies. Purpose The purpose of this security brief is to inform organizations of key password requirements and initiate internal compliance conversations. Use this security brief as a tool to enforce or strengthen your existing password policy. Learn more at fusionauth.io 2 According to Verizon’s 2017 Data Breach Investigations Report, 81% of hacking-related breaches leveraged either stolen and/or weak passwords. Financial, healthcare and public sector organizations 81% of hacking-related accounted for over half breaches leveraged of those breaches. either stolen and/or weak Password strength is an important security passwords. concern. With over four billion credentials Verizon BDIR 2017 stolen last year and data breaches averaging $3.62M in direct costs per incident, companies must be prepared for the security risks they face. While all applications should apply password constraints to discourage easy to guess passwords, many organizations are required to do so by law. It is necessary to have stringent password constraints in place in order to comply with industry regulations. Compliance is about fostering a culture that values user data and integrity and that culture starts at the top.
    [Show full text]
  • Analyzing Password Strength
    Analyzing Password Strength Martin M.A. Devillers Juli 2010 Password authentication requires no ABSTRACT specialized hardware, such as with finger- print authentication, can be easily imple- Password authentication is still the most mented by developers and just as easily used used authentication mechanism in today’s by users. In short: It’s usable. computer systems. In most systems, the But is it safe? The topic of “Security ver- password is set by the user and must adhere sus Usability” has always been of much de- to certain password requirements. Addition- bate in the computer security world (3). Us- ally, password checkers rank the strength of ers must be protected from harm by security a password to give the user an indication of controls, but these controls may not interfere how secure their password is. In this paper, (much) with the tasks the users want to per- we take a look at a large database of user form. For instance, a firewall that simply chosen passwords to determine the current blocks all traffic can be considered secure, state of affairs. In the end, we extract a mod- but heavily impedes the overall usability of el from the database and provide our own the system. password checker which ranks passwords in various ways. We ran this checker against Security experts or system developers are our dataset which shows that over 90% of usually the ones who have to make this tra- the passwords is highly insecure. deoff, but with password authentication, this task is essentially passed on to the user (3): INTRODUCTION One can either choose a short and simple password, which is easy to remember but As we perform increasingly important also easy to crack, or a very long and com- tasks from our living room computer, the plicated password, which is hard to remem- topic of computer security also becomes in- ber but also hard to crack.
    [Show full text]
  • Deepmnemonic: Password Mnemonic Genera- Tion Via Deep Attentive Encoder-Decoder Model
    1 DeepMnemonic: Password Mnemonic Genera- tion via Deep Attentive Encoder-Decoder Model Yao Cheng, Chang Xu, Zhen Hai*, and Yingjiu Li Abstract—Strong passwords are fundamental to the security of password-based user authentication systems. In recent years, much effort has been made to evaluate the password strength or to generate strong passwords. Unfortunately, the usability or memorability of the strong passwords has been largely neglected. In this paper, we aim to bridge the gap between strong password generation and the usability of strong passwords. We propose to automatically generate textual password mnemonics, i.e., natural language sentences, which are intended to help users better memorize passwords. We introduce DeepMnemonic, a deep attentive encoder-decoder framework which takes a password as input and then automatically generates a mnemonic sentence for the password. We conduct extensive experiments to evaluate DeepMnemonic on the real-world data sets. The experimental results demonstrate that DeepMnemonic outperforms a well-known baseline for generating semantically meaningful mnemonic sentences. Moreover, the user study further validates that the generated mnemonic sentences by DeepMnemonic are useful in helping users memorize strong passwords. Index Terms—Password mnemonic generation, deep neural network, attention mechanism, neural machine translation. F 1 INTRODUCTION OWADAYS, user authentication is the key to ensuring made to address the memorability of strong passwords. N the security of user accounts for most online services, Strong passwords are usually difficult for users to memorize such as social media, e-commerce, and online banking. because their entropy values are beyond many users’ mem- Although various authentication schemes have emerged orability [13] [14] [15].
    [Show full text]
  • Do Strong Web Passwords Accomplish Anything?
    Do Strong Web Passwords Accomplish Anything? Dinei Florencio,ˆ Cormac Herley Baris Coskun Microsoft Research ECE Department One Microsoft Way Polytechnic University Redmond, WA, USA Brooklyn, NY, USA [email protected], [email protected] [email protected] ABSTRACT Unfortunately, these recommendations appear somewhat We ¯nd that traditional password advice given to users out of date. If we enumerate the principal threats to a is somewhat dated. Strong passwords do nothing to user's credentials they would appear to be: protect online users from password stealing attacks such 1. Phishing as phishing and keylogging, and yet they place consid- erable burden on users. Passwords that are too weak of 2. Keylogging course invite brute-force attacks. However, we ¯nd that 3. A brute-force attack on the user's account (i.e. an relatively weak passwords, about 20 bits or so, are suf- attacker knows the userID and tries to guess the ¯cient to make brute-force attacks on a single account password) unrealistic so long as a \three strikes" type rule is in place. Above that minimum it appears that increasing 4. A bulk guessing attack on all accounts at the in- password strength does little to address any real threat. stitution If a larger credential space is needed it appears better to increase the strength of the userID's rather than the 5. Special knowledge or access attacks: passwords. For large institutions this is just as e®ective (a) guessing based on information about the user in deterring bulk guessing attacks and is a great deal better for users.
    [Show full text]
  • Encrypted Negative Password Using ELGAMAL
    © October 2020| IJIRT | Volume 7 Issue 5 | ISSN: 2349-6002 Encrypted Negative Password Using ELGAMAL Siddavaram Srivalli1, P. Vijaya Raghavulu2 1PG Student, Dept of CSE, Sri Annamacharya Institute of Technology and Science, Rajampet, Kadapa 2Asst.Professor, Dept of CSE, Sri Annamacharya Institute of Technology and Science, Rajampet, Kadapa Abstract - Secure password storage is a in systems major difficult to obtain passwords from high security fact based on password authentication, which has been systems. On the other side stealing authentication data widely used in authentication technique. Proposing a tables (containing usernames and passwords) in high password authentication framework that is designed for security systems is difficult. The aim of the project is secure password storage and it can be easily integrated to enhance password security. When carrying an into existing authentication systems. First, the received plain password from a client side is hashed using a online guessing attack, there is a limit to the number cryptographic hash function. Then, hashed password is of login attempts. However, passwords can be leaked converted into a negative password. Finally, the received from weak systems. Some old systems are more negative password is encrypted into an Encrypted vulnerable due to their lack of maintenance. The Negative Password (abbreviated as ENP) using a passwords are often reused, adversaries may log into symmetric-key algorithm. Using multi-iteration high security systems through cracked passwords from encryption could be employed to further improve low security systems. There are lots of corresponding security. Both the cryptographic hash function and ENPs for a given plain password, which makes attacks symmetric encryption make it difficult to crack (e.g., lookup table attack and rainbow table attack passwords from ENPs.
    [Show full text]
  • Design and Evaluation of a Data-Driven Password Meter
    Design and Evaluation of a Data-Driven Password Meter Blase Ur*, Felicia Alfieri, Maung Aung, Lujo Bauer, Nicolas Christin, Jessica Colnago, Lorrie Faith Cranor, Henry Dixon, Pardis Emami Naeini, Hana Habib, Noah Johnson, William Melicher *University of Chicago, Carnegie Mellon University [email protected] {fla, mza, lbauer, nicolasc, jcolnago, lorrie, hdixon, pardis, hana007, noah, billy}@cmu.edu ABSTRACT the strength of a password than other available meters and pro- Despite their ubiquity, many password meters provide inac- vides more useful, actionable feedback to users. Whereas most curate strength estimates. Furthermore, they do not explain previous meters scored passwords using very basic heuristics to users what is wrong with their password or how to im- [10,42,52], we use the complementary techniques of simulat- prove it. We describe the development and evaluation of a ing adversarial guessing using artificial neural networks [32] data-driven password meter that provides accurate strength and employing 21 heuristics to rate password strength. Our measurement and actionable, detailed feedback to users. This meter also gives users actionable, data-driven feedback about meter combines neural networks and numerous carefully com- how to improve their specific candidate password. We provide bined heuristics to score passwords and generate data-driven users with up to three ways in which they could improve their text feedback about the user’s password. We describe the password based on the characteristics of their specific pass- meter’s iterative development and final design. We detail the word. Furthermore, we automatically propose modifications to security and usability impact of the meter’s design dimensions, the user’s password through judicious insertions, substitutions, examined through a 4,509-participant online study.
    [Show full text]
  • Design and Implementation of Authentication Scheme By
    DESIGN AND IMPLEMENTATION OF AUTHENTICATION SCHEME BY ENCRYPTED NEGATIVE PASSWORD A Project Presented to the Faculty of California State Polytechnic University, Pomona In Partial Fulfillment Of the Requirements for the Degree Master of Science In Computer Science By Laxmi Chidri 2019 SIGNATURE PAGE PROJECT: DESIGN AND IMPLEMENTATION OF AUTHENTICATION SCHEME BY ENCRYPTED NEGATIVE PASSWORD AUTHOR: Laxmi Chidri DATE SUBMITTED: Fall 2019 Department of Computer Science Dr. Gilbert Young _______________________________________ Project Committee Chair Computer Science Dr. Yu Sun _______________________________________ Computer Science ii ABSTRACT Secure password storage is a vital aspect in systems based on password authentication, which is still the most widely used authentication technique, despite its some security flaws. In this project, we propose a password authentication framework that is designed for secure password storage and could be easily integrated into existing authentication systems. In our framework, first, the received plain password from a client is hashed through a cryptographic hash function (e.g., SHA-256). Then, the hashed password is converted into a negative password. Finally, the negative password is encrypted into an Encrypted Negative Password (abbreviated as ENP) using a symmetric-key algorithm (e.g., AES), and multi-iteration encryption could be employed to further improve security. The cryptographic hash function and symmetric encryption make it difficult to crack passwords from ENPs. Moreover, there are lots of corresponding ENPs for a given plain password, which makes precomputation attacks (e.g., lookup table attack and rainbow table attack) infeasible. The algorithm complexity analyses and comparisons show that the ENP could resist lookup table attack and provide stronger password protection under dictionary attack.
    [Show full text]
  • Just in Time Hashing
    Just in Time Hashing Benjamin Harsha Jeremiah Blocki Purdue University Purdue University West Lafayette, Indiana West Lafayette, Indiana Email: [email protected] Email: [email protected] Abstract—In the past few years billions of user passwords prove and as many users continue to select low-entropy have been exposed to the threat of offline cracking attempts. passwords, finding it too difficult to memorize multiple Such brute-force cracking attempts are increasingly dangerous strong passwords for each of their accounts. Key stretching as password cracking hardware continues to improve and as serves as a last line of defense for users after a password users continue to select low entropy passwords. Key-stretching breach. The basic idea is to increase guessing costs for the techniques such as hash iteration and memory hard functions attacker by performing hash iteration (e.g., BCRYPT[75] can help to mitigate the risk, but increased key-stretching effort or PBKDF2 [59]) or by intentionally using a password necessarily increases authentication delay so this defense is hash function that is memory hard (e.g., SCRYPT [74, 74], fundamentally constrained by usability concerns. We intro- Argon2 [12]). duce Just in Time Hashing (JIT), a client side key-stretching Unfortunately, there is an inherent security/usability algorithm to protect user passwords against offline brute-force trade-off when adopting traditional key-stretching algo- cracking attempts without increasing delay for the user. The rithms such as PBKDF2, SCRYPT or Argon2. If the key- basic idea is to exploit idle time while the user is typing in stretching algorithm cannot be computed quickly then we their password to perform extra key-stretching.
    [Show full text]
  • Using Improved D-HMAC for Password Storage
    Computer and Information Science; Vol. 10, No. 3; 2017 ISSN 1913-8989 E-ISSN 1913-8997 Published by Canadian Center of Science and Education Using Improved d-HMAC for Password Storage Mohannad Najjar1 1 University of Tabuk, Tabuk, Saudi Arabia Correspondence: Mohannad Najjar, University of Tabuk, Tabuk, Saudi Arabia. E-mail: [email protected] Received: May 3, 2017 Accepted: May 22, 2017 Online Published: July 10, 2017 doi:10.5539/cis.v10n3p1 URL: http://doi.org/10.5539/cis.v10n3p1 Abstract Password storage is one of the most important cryptographic topics through the time. Different systems use distinct ways of password storage. In this paper, we developed a new algorithm of password storage using dynamic Key-Hashed Message Authentication Code function (d-HMAC). The developed improved algorithm is resistant to the dictionary attack and brute-force attack, as well as to the rainbow table attack. This objective is achieved by using dynamic values of dynamic inner padding d-ipad, dynamic outer padding d-opad and user’s public key as a seed. Keywords: d-HMAC, MAC, Password storage, HMAC 1. Introduction Information systems in all kinds of organizations have to be aligned with the information security policy of these organizations. The most important components of such policy in security management is access control and password management. In this paper, we will focus on the password management component and mostly on the way of such passwords are stored in these information systems. Password is the oldest and still the primary access control technique used in information systems. Therefore, we understand that to have an access to an information system or a part of this system the authorized user hast to authenticate himself to such system by using an ID (username) and a password Hence, password storage is a vital component of the Password Access Control System.
    [Show full text]
  • Draft NIST SP 800-118, Guide to Enterprise Password Management
    RETIRED DRAFT April 1, 2016 The attached DRAFT document (provided here for historical purposes): Draft NIST Special Publication (SP) 800-118, Guide to Enterprise Password Management (posted for public comment on April 21, 2009) has been RETIRED. Information on other NIST cybersecurity publications and programs can be found at: http://csrc.nist.gov/. The following information was originally posted with the attached DRAFT document: Apr. 21, 2009 SP 800-118 DRAFT Guide to Enterprise Password Management NIST announces that Draft Special Publication (SP) 800-118, Guide to Enterprise Password Management, has been released for public comment. SP 800-118 is intended to help organizations understand and mitigate common threats against their character-based passwords. The guide focuses on topics such as defining password policy requirements and selecting centralized and local password management solutions. NIST requests comments on draft SP 800-118 by May 29, 2009. Please submit comments to 800-118comments @nist.gov with "Comments SP 800-118" in the subject line. Special Publication 800-118 (Draft) Guide to Enterprise Password Management (Draft) Recommendations of the National Institute of Standards and Technology Karen Scarfone Murugiah Souppaya NIST Special Publication 800-118 Guide to Enterprise Password (Draft) Management (Draft) Recommendations of the National Institute of Standards and Technology Karen Scarfone Murugiah Souppaya C O M P U T E R S E C U R I T Y Computer Security Division Information Technology Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899-8930 April 2009 U.S. Department of Commerce Gary Locke, Secretary National Institute of Standards and Technology Dr.
    [Show full text]
  • Protecting Passwords in the Event of a Password File Disclosure
    PolyPasswordHasher: Protecting Passwords In The Event Of A Password File Disclosure Justin Cappos Santiago Torres New York University New York University [email protected] [email protected] Abstract—Over the years, we have witnessed various the plain-text passwords from disk. Salting inserts a random password-hash database breaches that have affected small and value that complicates the use of tables that allow hackers to large companies, with a diversity of users and budgets. The indus- immediately look up passwords to match most hashes. Storing try standard, salted hashing (and even key stretching), has proven passwords with a salted hash is widely considered to be the to be insufficient protection against attackers who now have access best practice because of the level of protection offered and to clusters of GPU-powered password crackers. Although there the ease of implementation (e.g., salted hashing requires no are various proposals for better securing password storage, most do not offer the same adoption model (software-only, server-side) additional hardware or client software). as salted hashing, which may impede adoption. However, storing passwords with a salted hash is not a In this paper, we present PolyPasswordHasher, a software- panacea. That is, when stored password data has been com- only, server-side password storage mechanism that requires min- promised, attackers have proven themselves adept at quickly imal additional work for the server, but exponentially increases cracking large numbers of passwords, even when salted- the attacker’s effort. PolyPasswordHasher uses a threshold cryp- password hashes comprise the stored data. For example, Troy tosystem to interrelate stored password data so that passwords Hunt, a security researcher, showed that cracking 60% of a cannot be individually cracked.
    [Show full text]