CAPTCHA – Security affecting User Experience

Abstract

CAPTCHA -Completely Automated Public Turing test to tell Computers and Humans Apart -is a test with the aim to distinguish between malicious automatic software and real users in the era of Cyber security threats. Various types of CAPTCHA tests were developed, in order to address accessibility while implementing security. This research focuses on the users' attitudes and experiences related to use of the different kinds of tests. A questionnaire accompanied by experiencing five different CAPTCHA tests was performed among 212 users. Response times for each test and rate of success were collected automatically. The findings demonstrate that none of the existing tests are ideal. Although the participants were familiar with the Text-based test, they found it the most frustrating and non-enjoyable. Half of the participants failed in the Arithmetic-based test. While most of the participants found the picture and game based test enjoyable, their response time for those tests was the largest. The age factor was encountered as influencing both the attitude of the user and the performance, while younger users are more tolerant, have a better success rate, and are faster, the elder users found the tests annoying and time-consuming.

VIKAS: a new virtual keyboard-based simple and efficient text CAPTCHA verification scheme

“…This may give frustration to the user and reduce the interest of the user towards using a particular web service. A study has been carried out to investigate users' experiences and attitudes with different types of CAPTCHA tests (Gafni and Nagar, 2016). It is also suggested that the CAPTCHA test should be such that it protects web services from bots and not to exhaust persons with the difficult and confusing test.…”

“…However, this complex text CAPTCHA makes it difficult for the human to pass the test in a single attempt. This results in multiple attempts which are frustrating to the users (Yan and El Ahmad, 2008b;Gafni and Nagar, 2016). Hence, there is a need to design a text CAPTCHA which is difficult for the bots and easy for humans to pass the CAPTCHA test.…”

ZKSENSE: A Friction-less Privacy-Preserving Human Attestation Mechanism for Mobile Devices

“…CAPTCHAs are widely deployed across the internet to identify and block fraudulent non-human traffic. The major downsides of current CAPTCHA solutions (e.g., Securimage [4], hCaptcha [5]) include: (i) questionable accuracy: various past works demonstrate how CAPTCHAs can be solved within milliseconds [6][7][8][9][10], (ii) added friction: additional user actions are required (e.g., image, audio, math, or textual challenges) that significantly impoverish the user experience [11], especially on mobile devices, (iii) discrimination: poor implementations often block access to content [12], especially to visualimpaired users [13] (iv) serious privacy implications: to reduce friction, Google's reCAPTCHAv3 [14] replaces proof-of-work challenges with extensive user tracking. Google's servers attest user's humanness by collecting and validating behavioral data [15] (i.e., typing patterns, mouse clicks, stored cookies, installed plugins), thus raising significant privacy concerns [16][17][18].…”

You need to show that you are not a robot

“…These tests are named ‘CAPTCHA’ (Completely Automated Public Turing Test to tell Computers and Humans Apart). The classical tests consist of those almost illegible words, which are proposed by many websites, and which one has to decipher and rewrite correctly in order to demonstrate that one is not a robot (Abrich et al, 2011; Gafni and Nagar, 2016). According to Brodić et al, (2016), the reasons for using CAPTCHA are the following: they prevent spams on forums, they avoid having a large number of orders opened by users on sites that offer free services like Gmail, they protect user accounts from attacks through which bots discover users’ passwords and they concur to defend the validity of online surveys by detecting whether humans or bots answer the questionnaires.…”

“…Specifically, users' experience is analysed mainly in terms of response time for each test and rate of success (Gafni and Nagar, 2016) or in terms of limited website usability by respondents with all kinds of different disabilities (Pieper, 2012). In these type of studies, generally users are conceptualized in an instrumental way to understand better the functioning of the CAPTCHA tests.…”