Shinren : Non-monotonic trust management for distributed systems

The open and dynamic nature of modern distributed systems and pervasive environments presents significant challenges to security management. One solution may be trust management which utilises the notion of trust in order to specify and interpret security policies and make decisions on security-related actions. Most trust management systems assume monotonicity where additional information can only result in the increasing of trust. The monotonic assumption oversimplifies the real world by not considering negative information, thus it cannot handle many real world scenarios. In this paper we present Shinren, a novel non-monotonic trust management system based on bilattice theory and the anyworld assumption. Shinren takes into account negative information and supports reasoning with incomplete information, uncertainty and inconsistency. Information from multiple sources such as credentials, recommendations, reputation and local knowledge can be used and combined in order to establish trust. Shinren also supports prioritisation which is important in decision making and resolving modality conflicts that are caused by non-monotonicity

Covert QR codes: How to hide in the crowd

This paper investigates a novel approach of distributing a hidden message via public channels. The proposed approach employs visual subterfuge to conceal secret information within a QR code. Using a QR code reader, any individual can decode the public information contained in the QR code. However, only authorized users who have the necessary credentials will be able to obtain the secret message, which is encoded in the form of a secret QR code. We call this a Covert QR (CQR) code scheme. To embed the secret information, this approach exploits the error correction mechanism inherent in the QR code structure. By using QR codes to conceal information, the proposed scheme has the advantage of reducing the likelihood of attracting the attention of potential adversaries. In addition, the information in QR codes can be scanned and decoded through the visual channel. As such, the secret information can be distributed on printed media and is not restricted to an electronic form

Towards NFC payments using a lightweight architecture for the Web of Things

The Web (and Internet) of Things has seen the rapid emergence of new protocols and standards, which provide for innovative models of interaction for applications. One such model fostered by the Web of Things (WoT) ecosystem is that of contactless interaction between devices. Near Field Communication (NFC) technology is one such enabler of contactless interactions. Contactless technology for the WoT requires all parties to agree one common definition and implementation and, in this paper, we propose a new lightweight architecture for the WoT, based on RESTful approaches. We show how the proposed architecture supports the concept of a mobile wallet, enabling users to make secure payments employing NFC technology with their mobile devices. In so doing, we argue that the vision of the WoT is brought a step closer to fruition