CAPTCHaStar! A novel CAPTCHA based on interactive shape discovery

Over the last years, most websites on which users can register (e.g., email providers and social networks) adopted CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) as a countermeasure against automated attacks. The battle of wits between designers and attackers of CAPTCHAs led to current ones being annoying and hard to solve for users, while still being vulnerable to automated attacks. In this paper, we propose CAPTCHaStar, a new image-based CAPTCHA that relies on user interaction. This novel CAPTCHA leverages the innate human ability to recognize shapes in a confused environment. We assess the effectiveness of our proposal for the two key aspects for CAPTCHAs, i.e., usability, and resiliency to automated attacks. In particular, we evaluated the usability, carrying out a thorough user study, and we tested the resiliency of our proposal against several types of automated attacks: traditional ones; designed ad-hoc for our proposal; and based on machine learning. Compared to the state of the art, our proposal is more user friendly (e.g., only some 35% of the users prefer current solutions, such as text-based CAPTCHAs) and more resilient to automated attacks.Comment: 15 page

A heuristic evaluation of the Facebook's advertising tool beacon

Interface usability is critical to the successful adoption of information systems. The aim of this study is to evaluate interface of Facebook's advertising tool Beacon by using privacy heuristics [4]. Beacon represents an interesting case study because of the negative media and user backlash it received. The findings of heuristic evaluation suggest violation of privacy heuristics [4]. Here, analysis identified concerns about user choice and consent, integrity and security of data, and awareness and notice. Beacon was an innovative tool, therefore, its systematic evaluation was needed in order to identify privacy problems, their causes and subsequent consequences. The study provides useful insights to human computer interaction (HCI) designers of online social networks

Towards Developing an Online Social Media-based Mobile Learning System

The advancement of Information and Communication Technology (ICT) and the Internet revolution gave rise to the several learning technologies on the web and mobile platform. During the last decade, the social media network became available for users to socialise and collaborate among peer group. Hence, The integration of e-learning and social media using mobile device as access point is to allow for learning and collaboration anytime, anywhere. This study seeks to provide learning on the social network platform for users to view the application on a mobile device and also foster collaboration among scholars. The system was developed using an open source Content Management System (CMS) Wordpress and Buddypress running on a WAMP or XAMPP server. MySQL was used as database. The usability of the System on the different mobile devices used was evaluated by identifying the usability attributes; designing a questionnaire based on those attributes and then analyzing the results with Statistical Package for Social Science (SPSS). The results showed that the learning system had a good usability score on mobile device

Human Factors and Innovation with Mobile Devices

Advancements in technology are a significant driving force in educational innovation, but a strong focus on technology means that human aspects and implications may not be given the attention they deserve. This chapter examines usability issues surrounding the use of mobile devices in learning. A key aim is to empower educators and learners to take control of personal devices and realise their potential in relation to teaching and learning. The background section reviews the development of usability studies and explores why mobile device usability presents specific new challenges. The impact of changing requirements in education, and new visions for ways of thinking and competences that learners should be acquiring, are also examined. Finally, the chapter provides a set of concepts that can inform conversations between educators and learners, mobile system engineers, developers, support staff, and others

Survey and Systematization of Secure Device Pairing

Secure Device Pairing (SDP) schemes have been developed to facilitate secure communications among smart devices, both personal mobile devices and Internet of Things (IoT) devices. Comparison and assessment of SDP schemes is troublesome, because each scheme makes different assumptions about out-of-band channels and adversary models, and are driven by their particular use-cases. A conceptual model that facilitates meaningful comparison among SDP schemes is missing. We provide such a model. In this article, we survey and analyze a wide range of SDP schemes that are described in the literature, including a number that have been adopted as standards. A system model and consistent terminology for SDP schemes are built on the foundation of this survey, which are then used to classify existing SDP schemes into a taxonomy that, for the first time, enables their meaningful comparison and analysis.The existing SDP schemes are analyzed using this model, revealing common systemic security weaknesses among the surveyed SDP schemes that should become priority areas for future SDP research, such as improving the integration of privacy requirements into the design of SDP schemes. Our results allow SDP scheme designers to create schemes that are more easily comparable with one another, and to assist the prevention of persisting the weaknesses common to the current generation of SDP schemes.Comment: 34 pages, 5 figures, 3 tables, accepted at IEEE Communications Surveys & Tutorials 2017 (Volume: PP, Issue: 99

ECommerce of the Spanish online pharmacies: web design and visibility on the Internet

En el trabajo presentado realizamos un estudio empírico que parte de la selección de las farmacias españolas online que venden por Internet mejor posicionadas en SEO. Mediante la utilización de una serie de herramientas online gratuitas hemos analizado sus diseños web, con especial mención al diseño web adaptativo, a la usabilidad y a la accesibilidad, así como su visibilidad en la Red y presencia en los medios sociales. Estas farmacias objeto del estudio presentan un nivel de SEO elevado, al igual que usabilidad y visibilidad, con presencia en las principales redes sociales Facebook y Twitter, mostrando carencias en la accesibilidad y adaptación de sus diseños web al comercio electrónico móvil.The work presented perform an empirical study of the Spanish selection of online pharmacies that sold in Internet with best SEO position in Google. We have analyzed, with free online tools, their web design, with special mention of the adaptative web design, usability and accessibility, and the visibility on the Web and social media presence. The sepharmacies under study exhibit a high level of SEO, usability and visibility, with presence in major social networks Facebook and Twitter, showing gaps in accessibility and adaptation of web designs for mobile commerce