A secure over-the-air programming scheme in wireless sensor networks

Over-The-Air dissemination of code updates in Wireless Sensor Networks (WSNs) have been researchers’ point of interest in past a few years and more importantly security challenges toward remote propagation of code update have taken the majority of efforts in this context. Many security models have been proposed to establish a balance between the energy consumption and security strengthen with having their concentration on constraint nature of WSN nodes. For authentication purposes most of them have used Merkle-Hash-Tree to avoid using multiple public cryptography operations. These models mostly have assumed an environment in which security has to be in a standard level and therefore they have not investigated the tree structure for mission-critical situations in which security has to be in maximum possible extent (e.g. military zones). Two major problems have been identified in Merkle Tree structure which is used in Seluge scheme, including: 1) an exponential growth in number of overhead packets when block size of hash algorithm used in design is increased. 2) Limitation of using hash algorithms with larger block size of 11 bytes when payload size is set to 72 bytes. Then several existing security models are investigated for possible vulnerabilities and a set of countermeasures correspondingly named Security Model Requirements (SMR) is provided. After concentrating on Seluge’s design, a new secure Over-The-Air Programming (OTAP) scheme named Seluge++ is proposed that complies with SMR and replaces the use of inefficient Merkle Tree with a novel method

Dynamic Reconfiguration for Software and Hardware Heterogeneous Real-time WSN

International audienceWireless Sensor Network (WSN) technology has imposed itself in civilian and industrial applications as a promising technology for wireless monitoring due to its wireless connectivity, removing many hardware constraints. Initially used in low frequency sampling applications, the increasing performances of electronic circuits has driven WSNs to integrate more powerful computation units, paving the way for a new generation of applications based on distributed computation. These new applications (process control, active control, visual surveillance, multimedia streaming) involving medium to heavy computation present real-time requirements at node level where reactivity becomes a primary concern as well as at the network level where latency must be bounded. In this paper, we present the implementation of a high-level language MinTax coupled with an in-situ compilation solution for real time Operating Systems enabling energy-aware dynamic reconfiguration while supporting hardware heterogeneity in Wireless Sensor Networks

Reprogramming hardware-software heterogeneous Wireless Sensor Networks

International audienceReprogramming (reconfiguring) software running on the nodes of a WSN (Wireless Sensor Networks) is needed to update or add new functionalities or fix existing bugs. Reducing the amount of data sent to the node via the radio interface means reducing the energy consumed by the sender and receiver nodes, enabling them to run for longer. We present a solution for performing such functionality exchanges on different node hardware, each running under different operating systems. The universality of our solution is based upon the semantics of a high-level language called MinTax which is compiled in-situ, on the node itself. In order to validate the feasibility of a hardware-software heterogeneous WSN, we present the case of a functionality sent between two different hardware nodes, one running ContikiOS and the other, FunkOS