Open authorization (OAuth) is an open protocol, which allows secure authorization in a simple and standardized way from third-party applications accessing online services, based on the representational state transfer (REST) web architecture. OAuth has been designed to provide an authorization layer, typically on top of a secure transport layer such as HTTPS. The Internet of Things (IoTs) refers to the interconnection of billions of resource-constrained devices, denoted as smart objects, in an Internet-like structure. Smart objects have limited processing/memory capabilities and operate in challenging environments, such as low-power and lossy networks. IP has been foreseen as the standard communication protocol for smart object interoperability. The Internet engineering task force constrainedRESTful environments working group has defined the constrained application protocol (CoAP) as a generic web protocol for RESTful-constrained environments, targeting machine-tomachine applications, which maps to HTTP for integration with the existing web. In this paper, we propose an architecture targeting HTTP/CoAP services to provide an authorization framework, which can be integrated by invoking an external oauth-based authorization service (OAS). The overall architecture is denoted as IoT-OAS. We also present an overview of significant IoT application scenarios. The IoT-OAS architecture is meant to be flexible, highly configurable, and easy to integrate with existing services. Among the advantages achieved by delegating the authorization functionality, IoT scenarios benefit by: 1) lower processing load with respect to solutions, where access control is implemented on the smart object; 2) fine-grained (remote) customization of access policies; and 3) scalability, without the need to operate directly on the device.

In the emerging field of the Internet of Things (IoT), Wireless Sensor Networks (WSNs) have a key role to play in sensing and collecting measures on the surrounding environment. In the deployment of large scale observation systems in remote areas, when there is not a permanent connection with the Internet, WSNs are calling for replication and distributed storage techniques that increase the amount of data stored within the WSN and reduce the probability of data loss. Unlike conventional network data storage, WSN-based distributed storage is constrained by the limited resources of the sensors. In this paper, we propose a low-complexity distributed data replication mechanism to increase the resilience of WSNbased distributed storage at large scale. In particular, we propose a simple, yet accurate, analytical modeling framework and an extensive simulation campaign, which complement experimental results on the SensLab testbed. The impact of several key parameters on the system performance is investigated.

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Abstract-In Wireless Sensor Networks (WSNs) for monitoring applications, energy saving and fast data collection are two challenging tasks. Asynchronous radio duty cycling protocols can achieve very low energy consumption in low traffic conditions and they are fault-tolerant to clock drifts. However, they may exhibit a delay degradation due to the decoupled wakeup periods of the nodes. In this paper, we present RAWMAC, a cross-layer approach where RPL, a tree-based routing protocol, orchestrates the asynchronous duty-cycled ContikiMAC MAC layer. The wake-up instants of the nodes are dynamically aligned, with respect to the RPL topology, to minimize the delay for data collection. We implement RAWMAC for the Contiki operating system and we analyze the impact of several key system parameters. Results show that RAWMAC outperforms ContikiMAC in terms of delay for data collection, while keeping the same performance in terms of throughput and energy consumption.

Abstract-In scenarios like the surveillance of isolated areas, when the border node of a network does not have a permanent connection with the Internet, Wireless Sensor Networks (WSNs) are calling for resilient in-network data storage techniques which minimize the risk of data loss. The efficiency of these techniques can be largely improved exploiting information on the status of the network, such as that used by routing protocols. In particular, one of the most used protocol in Internet of Things (IoT) scenarios is the IPv6 Routing Protocol for Low power and lossy networks (RPL). In this paper, we propose a redundant distributed data storage and retrieval mechanism to increase the resilience and storage capacity of a RPL-based WSN against local memory shortage. We evaluate our approach in the Contiki operating system through extensive analysis with the Cooja simulator.