Completely Automated Public Physical test to tell Computers and Humans Apart: A usability study on mobile devices

A very common approach adopted to fight the increasing sophistication and dangerousness of malware and hacking is to introduce more complex authentication mechanisms. This approach, however, introduces additional cognitive burdens for users and lowers the whole authentication mechanism acceptability to the point of making it unusable. On the contrary, what is really needed to fight the onslaught of automated attacks to users data and privacy is to first tell human and computers apart and then distinguish among humans to guarantee correct authentication. Such an approach is capable of completely thwarting any automated attempt to achieve unwarranted access while it allows keeping simple the mechanism dedicated to recognizing the legitimate user. This kind of approach is behind the concept of Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA), yet CAPTCHA leverages cognitive capabilities, thus the increasing sophistication of computers calls for more and more difficult cognitive tasks that make them either very long to solve or very prone to false negatives. We argue that this problem can be overcome by substituting the cognitive component of CAPTCHA with a different property that programs cannot mimic: the physical nature. In past work we have introduced the Completely Automated Public Physical test to tell Computer and Humans Apart (CAPPCHA) as a way to enhance the PIN authentication method for mobile devices and we have provided a proof of concept implementation. Similarly to CAPTCHA, this mechanism can also be used to prevent automated programs from abusing online services. However, to evaluate the real efficacy of the proposed scheme, an extended empirical assessment of CAPPCHA is required as well as a comparison of CAPPCHA performance with the existing state of the art. To this aim, in this paper we carry out an extensive experimental study on both the performance and the usability of CAPPCHA involving a high number of physical users, and we provide comparisons of CAPPCHA with existing flavors of CAPTCHA

Designing Mobile Friendly CAPTCHAs: An Exploratory Study.

CAPTCHAs (Completely Automated Public Turing Test to Tell Computers and Humans Apart) are one of the most widely used authentication mechanisms that help to prevent online service abuse. With the advent of mobile computing, mobile devices such as smartphones and tablets have become the primary way people access the Internet. As a result, increasing attention has been paid to designing CAPTCHAs that are mobile friendly. Although such CAPTCHAs generally show their advantages over traditional ones, it is still unclear what the best practices are for designing a CAPTCHA scheme that is easy to use on mobile devices. In this paper, we present an exploratory study that focuses on developing a more holistic view of usability issues with interactive CAPTCHAs to inform design guidance. This is done through investigating the usability performance of seven mobile friendly CAPTCHA schemes representing five different CAPTCHA types

TAPCHA: An Invisible CAPTCHA Scheme

TAPCHA is a universal CAPTCHA scheme designed for touch-enabled smart devices such as smartphones, tablets and smartwatches. The main difference between TAPCHA and other CAPTCHA schemes is that TAPCHA retains its security by making the CAPTCHA test ‘invisible’ for the bot. It then utilises context effects to maintain the readability of the instruction for human users which eventually guarantees the usability of the scheme. Two reference designs, namely TAPCHA SHAPE & SHADE and TAPCHA MULTI are developed to demonstrate the use of this scheme

A Novel Design of Audio CAPTCHA for Visually Impaired Users

CAPTCHAs are widely used by web applications for the purpose of security and privacy. However, traditional text-based CAPTCHAs are not suitable for sighted users much less users with visual impairments. To address the issue, this paper proposes a new mechanism for CAPTCHA called HearAct, which is a real-time audio-based CAPTCHA that enables easy access for users with visual impairments. The user listens to the sound of something (the “sound-maker”), and he/she must identify what the sound-maker is. After that, HearAct identifies a word and requires the user to analyze a word and determine whether it has the stated letter or not. If the word has the letter, the user must tap and if not, they swipe. This paper presents our HearAct pilot study conducted with thirteen blind users. The preliminary user study results suggest the new form of CAPTCHA has a lot of potential for both blind and visual users. The results also show that the HearAct CAPTCHA can be solved in a shorter time than the text-based CAPTCHAs because HearAct allows users to solve the CAPTCHA using gestures instead of typing. Thus, participants preferred HearAct over audio-based CAPTCHAs. The results of the study also show that the success rate of solving the HearAct CAPTCHA is 82.05% and 43.58% for audio CAPTCHA. A significant usability differences between the System Usability score for HearAct CAPTCHA method was 88.07 compared to audio CAPTCHA was 52.11%. Using gestures to solve the CAPTCHA challenge is the most preferable feature in the HearAct solution. To increase the security of HearAct, it is necessary to increase the number of sounds in the CAPTCHA. There is also a need to improve the CAPTCHA solution to cover wide range of users by adding corresponding image with each sound to meet deaf users’ needs; they then need to identify the spelling of the sound maker’s word

Context-Awareness in Android Application: Context-Aware Personal Financial Assistance (CAPFA)

This report describes system that examines and reacts to an individual's changing context which can be computer context, user context, or physical context. The author defines mobile computing, context-awareness and financial goals. Integration between these three concept leads to the idea of developing Context-Aware Personal Financial Assistance (CAPFA). This report summarizes the reasons why people fail to achieve their financial goal(s) and how the proposed solution, CAPFA can helps to minimize the rate of failure. CAPFA, an Android context-aware application supports users in managing their financial goal(s). It ensures that user will commit to the financial goal(s) set. The objectives of developing CAPFA are to study how context-aware can be applied in personal financial assistance tool and to develop a context-aware personal financial assistance tool for assisting user in achieving financial goal(s). Software Engineering Process will be the project development guidance from the very beginning to the very end of developing CAPF A. This report describes the hardware and software used, architecture implemented, and functions available

Visual Cryptography-Based Secure QR Payment System Design and Implementation

It is important to validate the Merchant and the Client to increase confidence in online transactions. At present, only the Client is checked against the merchant server. The research in this paper will show you how to create and launch a QR code-based payment system that is both secure and convenient for users. As a result of their capacity to facilitate instantaneous transactions and offer unparalleled ease of use, QR codes have seen explosive growth in the past few years. QR-based online payment systems are easy to use but susceptible to various assaults. So, for the level of security given by transaction processing to hold, the secrecy and integrity of each payment procedure must be guaranteed. In addition, the online payment system must verify each transaction from both the sender's and the recipient's perspectives. The study's QR-based method is kept safe through visual cryptography. The suggested approach takes advantage of visual cryptography via a web-based application

Accessibility of mobile applications for tourism - is equal access a reality?

With the increasing use of smartphones in people’s daily lives, mobile accessibility has become a key factor for them. Tourism is one of the sectors that has benefited the most from this growth but has not yet reached its full potential as accessibility has not yet been fully exploited. The main goal of this study is to assess accessibility in mobile applications for the tourism sector. Thus, 14 mobile applications were analyzed, using a manual and automatic methodology through the proposal of an evaluation model divided by quantitative and qualitative requirements, as well as the use of features such as VoiceOver and TalkBack. The results show a high overall number of errors in most quantitative requirements as well as non-compliance with most qualitative requirements. On iPhone 4, “Viseu – Guia da Cidade” was the application with the highest rating, while on Wiko GOA, it was the “JiTT.Travel Funchal” application. In turn, on iPhone 6 Plus, iPhone XR, Nokia 5.1 and OnePlus 6 devices, the best results were achieved by the “Viseu – Guia da Cidade,” “JiTT.Travel Funchal” and “TUR4all” applications. Regarding the accessibility of mobile applications on different versions of the same mobile operating system, it was concluded that there are no differences in their accessibility on both operating systems (iOS and Android). Finally, regarding the accessibility of applications on smartphones with different screen sizes, there are also no differences in their accessibility.This work is financed by the ERDF—European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation—COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT-Fundação para a Ciência e a Tecnologia within project POCI-01-0145-FEDER-031309 entitled “PromoTourVR-Promoting Tourism Destinations with Multisensory Immersive Media.”info:eu-repo/semantics/publishedVersio