The Internet of Things (IoT) is becoming increasingly important in several fields of industrial applications and personal applications, such as medical e-health, smart cities, etc. The research into protocols and security aspects related to this area is continuously advancing in making these networks more reliable and secure, taking into account these aspects by design. Bootstrapping is a procedure by which a user obtains key material and configuration information, among other parameters, to operate as an authenticated party in a security domain. Until now solutions have focused on re-using security protocols that were not developed for IoT constraints. For this reason, in this work we propose a design and implementation of a lightweight bootstrapping service for IoT networks that leverages one of the application protocols used in IoT : Constrained Application Protocol (CoAP). Additionally, in order to provide flexibility, scalability, support for large scale deployment, accountability and identity federation, our design uses technologies such as the Extensible Authentication Protocol (EAP) and Authentication Authorization and Accounting (AAA). We have named this service CoAP-EAP. First, we review the state of the art in the field of bootstrapping and specifically for IoT. Second, we detail the bootstrapping service: the architecture with entities and interfaces and the flow operation. Third, we obtain performance measurements of CoAP-EAP (bootstrapping time, memory footprint, message processing time, message length and energy consumption) and compare them with PANATIKI. The most significant and constrained representative of the bootstrapping solutions related with CoAP-EAP. As we will show, our solution provides significant improvements, mainly due to an important reduction of the message length.

Internet of Things (IoT) networks are the pillar of recent novel scenarios, such as smart cities or e-healthcare applications. Among other challenges, these networks cover the deployment and interaction of small devices with constrained capabilities and Internet protocol (IP)-based networking connectivity. These constrained devices usually require connection to the Internet to exchange information (e.g., management or sensing data) or access network services. However, only authenticated and authorized devices can, in general, establish this connection. The so-called authentication, authorization and accounting (AAA) services are in charge of performing these tasks on the Internet. Thus, it is necessary to deploy protocols that allow constrained devices to verify their credentials against AAA infrastructures. The Protocol for Carrying Authentication for Network Access (PANA) has been standardized by the Internet engineering task force (IETF) to carry the Extensible Authentication Protocol (EAP), which provides flexible authentication upon the presence of AAA. To the best of our knowledge, this paper is the first deep study of the feasibility of EAP/PANA for network access control in constrained devices. We provide light-weight versions and implementations of these protocols to fit them into constrained devices. These versions have been designed to reduce the impact in standard specifications. The goal of this work is two-fold: (1) to demonstrate the feasibility of EAP/PANA in IoT devices; (2) to provide the scientific community with the first light-weight interoperable implementation of EAP/PANA for constrained devices in the Contiki operating system (Contiki OS), called PANATIKI. The paper also shows a testbed, simulations and experimental results obtained from real and simulated constrained devices.

The Internet-of-Things (IoT) landscape is expanding with new radio technologies. In addition to the Low-Rate Wireless Personal Area Network (LR-WPAN), the recent set of technologies conforming the so-called Low-Power Wide Area Networks (LP-WAN) offers long-range communications, allowing one to send small pieces of information at a reduced energy cost, which promotes the creation of new IoT applications and services. However, LP-WAN technologies pose new challenges since they have strong limitations in the available bandwidth. In general, a first step prior to a smart object being able to gain access to the network is the process of network access authentication. It involves authentication, authorization and key management operations. This process is of vital importance for operators to control network resources. However, proposals for managing network access authentication in LP-WAN are tailored to the specifics of each technology, which could introduce interoperability problems in the future. In this sense, little effort has been put so far into providing a wireless-independent solution for network access authentication in the area of LP-WAN. To fill this gap, we propose a service named Low-Overhead CoAP-EAP (LO-CoAP-EAP), which is based on previous work designed for LR-WPAN. LO-CoAP-EAP integrates the use of Authentication, Authorization and Accounting (AAA) infrastructures and the Extensible Authentication Protocol (EAP) protocol. For this integration, we use the Constrained Application Protocol (CoAP) to design a network authentication service independent of the type of LP-WAN technology. LO-CoAP-EAP represents a trade-off between flexibility, wireless technology independence, scalability and performance in LP-WAN.

In the renowned Internet-of-Thing (IoT) networks, it is expected a vast number of devices with IP connectivity and constrained capabilities. Due to reduced resources they are target of different type of attacks and providing security has become a basic pillar for the success and evolution of IoT. Among the specific key security aspects are the authentication, access control and key distribution for data protection. In particular, all these aspects are included in the process of bootstrapping, which allows a Smart Object to join a network domain in a secure fashion. This process, which indeed involves authentication, authorization and key distribution, typically requires communication between the Smart Object and an entity, the Controller, in charge of steering the bootstrapping process within the network’s domain. However, direct communication between both might be impeded, e.g., when the entity is unreachable by radio, or the Smart Object does not have a routable IP address until it is successfully authenticated and authorized to join the network. A common solution is to use an intermediate entity (the Intermediary) to aid in this task. For example, the Zigbee IP standard defines a relay for the Protocol for Carrying Authentication for Network Access (PANA). Moreover, the IETF is exploring the use of an Intermediary to help this process. In this work we analyse, explore and design an intermediary based on CoAP. We pay attention to the authentication with the Extensible Authentication Protocol (EAP) and CoAP, which has resulted in a more constrained alternative to PANA for EAP-based bootstrapping in IoT. Nevertheless, our design of the CoAP-based intermediary is so general that it is independent of the authentication protocol in use. In particular, we have analysed as intermediary the usage of a CoAP proxy, as defined in the CoAP standard; alternatively we have introduced the concept of the CoAP relay and CoAP stateless proxy. We evaluate the performance of each solution and we compare between them and with PANA relay.

Network access authentication is a key procedure for network operators to control user access to the network service. The IETFs recently finished its major work in this area by standardizing an IP-based protocol named Protocol for Carrying Authentication for Network Access (PANA). We provide a comprehensive survey of PANA based on developed IETF standards, and describe its applicability to both existing and emerging network environments.