Biblio

We propose an approach to enforce security in disruption- and delay-tolerant networks (DTNs) where long delays, high packet drop rates, unavailability of central trusted entity etc. make traditional approaches unfeasible. We use trust model based on subjective logic to continuously evaluate trustworthiness of security credentials issued in distributed manner by network participants to deal with absence of centralised trusted authorities.

We consider Delay Tolerant Mobile Social Networks (DTMSNs), made of wireless nodes with intermittent connections and clustered into social communities. The lack of infrastructure and its reliance on nodes' mobility make routing a challenge. Network Coding (NC) is a generalization of routing and has been shown to bring a number of advantages over routing. We consider the problem of pollution attacks in these networks, that are a very important issue both for NC and for DTMSNs. Our first contribution is to propose a protocol which allows controlling adversary's capacity by combining cryptographic hash dissemination and error-correction to ensure message recovery at the receiver. Our second contribution is the modeling of the performance of such a protection scheme. To do so, we adapt an inter-session NC model based on a fluid approximation of the dissemination process. We provide a numerical validation of the model. We are eventually able to provide a workflow to set the correct parameters and counteract the attacks. We conclude by highlighting how these contributions can help secure a real-world DTMSN application (e.g., a smart-phone app.).

The delay-tolerant-network (DTN) model is becoming a viable communication alternative to the traditional infrastructural model for modern mobile consumer electronics equipped with short-range communication technologies such as Bluetooth, NFC, and Wi-Fi Direct. Proximity malware is a class of malware that exploits the opportunistic contacts and distributed nature of DTNs for propagation. Behavioral characterization of malware is an effective alternative to pattern matching in detecting malware, especially when dealing with polymorphic or obfuscated malware. In this paper, we first propose a general behavioral characterization of proximity malware which based on naive Bayesian model, which has been successfully applied in non-DTN settings such as filtering email spams and detecting botnets. We identify two unique challenges for extending Bayesian malware detection to DTNs ("insufficient evidence versus evidence collection risk" and "filtering false evidence sequentially and distributedly"), and propose a simple yet effective method, look ahead, to address the challenges. Furthermore, we propose two extensions to look ahead, dogmatic filtering, and adaptive look ahead, to address the challenge of "malicious nodes sharing false evidence." Real mobile network traces are used to verify the effectiveness of the proposed methods.