Biblio

Low-power wireless networks provide IPv6 connectivity through 6LoWPAN, a set of standards to aggressively compress IPv6 packets over small maximum transfer unit (MTU) links such as 802.15.4.The entire purpose of IP was to interconnect different networks, but we find that different 6LoWPAN implementations fail to reliably communicate with one another. These failures are due to stacks implementing different subsets of the standard out of concern for code size. We argue that this failure stems from 6LoWPAN's design, not implementation, and is due to applying traditional Internet protocol design principles to low- power networks.We propose three design principles for Internet protocols on low-power networks, designed to prevent similar failures in the future. These principles are based around the importance of providing flexible tradeoffs between code size and energy efficiency. We apply these principles to 6LoWPAN and show that the modified protocol provides a wide range of implementation strategies while allowing implementations with different strategies to reliably communicate.

Users often need to authenticate at situated displays in order to, for example, make purchases, access sensitive information, or confirm an identity. However, the exposure of interactions in public spaces introduces a large attack surface (e.g., observation, smudge or thermal attacks). A plethora of authentication models and input modalities that aim at disguising users' input has been presented in the past. However, a comprehensive analysis on the requirements for secure and usable authentication on public displays is still missing. This work presents 13 design considerations suitable to inform practitioners and researchers during the development process of authentication systems for situated displays in public spaces. It draws on a comprehensive analysis of prior literature and subsequent discussion with five experts in the fields of pervasive displays, human-computer-interaction and usable security.

In this paper we present a case study of applying fitness dimensions in API design assessment. We argue that API assessment is company specific and should take into consideration various stakeholders in the API ecosystem. We identified new fitness dimensions and introduced the notion of design considerations for fitness dimensions such as priorities, tradeoffs, and technical versus cognitive classification.