A recent development emanating from RFID technology is Near Field Communication (NFC). Basically, NFC is a popular short range (<10 cm) wireless communication technology with applications in areas sensitive to security and privacy concerns such as contactless payment. Since NFC communications require very close proximity between two communicating devices (e.g., a smartcard and a terminal), it is generally believed that Man-in-the-Middle (MITM) attacks are practically infeasible here. Contrasting this belief, in this paper, we successfully establish MITM attack in NFC communications between a passive tag and an active terminal. We carefully present physical fundamentals of the attack, our engineering design, and results of successful attack implementation. Subsequently, we present the practical applicability of our MITM attack that exploits a potential vulnerability in EMV based contactless payment protocol, which arises due to separation between card authentication and transaction authorization phases. We demonstrate how an attacker can compromise the integrity of a contactless payment using a malicious MITM card, and also present multiple attack/victim scenarios to analyze different types of impacts of our attack. Further, we conduct rigorous experimental studies to analyze both hardware and practical ramifications of our attack. Finally, we propose a mechanism to detect the MITM attack based on experimental analysis that demands no additional hardware.

Listening to text using read-aloud applications is a popular way for people to consume content when their visual attention is situationally impaired (e.g., commuting, walking, tired eyes). However, due to the linear nature of audio, such apps do not support skimming---a non-linear, rapid form of reading---essential for quickly grasping the gist and organization of difficult texts, like academic or professional documents. To support auditory skimming for situational impairments, we (1) identified the user needs and challenges in auditory skimming through a formative study (N=20), (2) derived the concept of "eyes-reduced" skimming that blends auditory and visual modes of reading, inspired by how participants mixed visual and non-visual interactions, (3) generated a set of design guidelines for eyes-reduced skimming, and (4) designed and evaluated a novel audio skimming app that embodies the guidelines. Our in-situ preliminary observation study (N=6) suggested that participants were positive about our design and were able to auditorily skim documents. We discuss design implications for eyes-reduced reading, read-aloud apps, and text-to-speech engines.

Reading printed documents and writing on a paper pose a great challenge for visually-impaired people. Existing studies that attempt to solve these challenges are expensive and not feasible in low-income context. Moreover, these studies solve reading and writing problems separately. On the contrary, in this study, we propose FLight, a low-cost reading and writing system for economically less-privileged people. FLight uses ink-based Braille characters as the medium of textual representation. This helps in keeping a compact spatial representation of texts, yet achieving a low-cost status. Additionally, FLight utilizes a low-cost wearable device to enhance ease of reading by visually-impaired people. We conduct a participatory design and iterative evaluation involving five visually-impaired children in Bangladesh for more than 18 months. Our user evaluation reveals that FLight is easy-to-use, and exhibits a potential low-cost solution for economically less-privileged visually-impaired people.

A recent development emanating from the widely used RFID technology is Near Field Communication (NFC). Basically, NFC is a popular short range (<;10cm) wireless communication technology with applications in areas sensitive to security and privacy concerns including contact-less payment. Since NFC communications require very close proximity between two communicating devices (for example a smartcard and a reader), it is generally believed that Man-in-the-Middle (MITM) attacks are practically infeasible here. On the contrary to this general belief, in this paper, we successfully establish MITM attacks in NFC communications between a passive tag and an active reader. We present physical fundamentals of the attack, our engineering design, and results of our successful implementation. We also present practical impacts of the attack from the perspective of how a malicious user can leverage our MITM attack to compromise integrity of contact-less payment transactions. Finally, we present insights to combat the MITM attack in NFC communications towards the end of the paper.