Performance Analysis of 6LoWPAN and CoAP for Secure Communications in Smart Homes Rafael de Jesus Martins 1 , Vinicius Garcez Schaurich 1 , Luis Augusto Dias Knob 1 , Juliano Araujo Wickboldt 1 , Alberto Schaeffer Filho 1 , Lisandro Zambenedetti Granville 1 and Marcelo Pias 2 1 Institute of Informatics, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil 2 Globosense Ltd., Cambridge, United Kingdom 1,2 Email: {rjmartins, vgschaurich, ladknob, jwickboldt, alberto, granville}@inf.ufrgs.br, marcelo@globosense.com Abstract—Smart grids and smart homes improve energy man- agement by coupling communication capabilities to their devices. Due to computational constraints of these devices, employment of simplified communication protocols is necessary. In this paper, we investigate the use of communication protocols based on CoAP and 6LoWPAN in smart home environments. Specifically, we analyze the vulnerabilities a smart home employing CoAP and 6LoWPAN may be susceptible to. We also present a performance analysis of the use of these protocols for ensuring secure com- munications in smart homes. I. I NTRODUCTION Smart grids [1] enable sophisticated management and distribution of electricity by incorporating Information and Communication Technology (ICT) to the legacy electricity network 1 . In a smart grid environment, sensors and actuators, deployed along the power grid, communicate with the utility company using a bidirectional communication channel [2]; sensors measure and convert properties of the energy flow (e.g., voltage, current, power factor) into data; an actuator is a device able to execute actions (e.g., interrupting energy flow) based on signals it receives from sensors. Occasionally, a single device can accumulate the roles of sensor and actuator, as is the case of smart meters [1]. In smart grids, power meters deployed at customer premises are replaced by smart meters. Unlike their legacy counterpart, smart meters maintain a communication channel with the utility company in addition to their traditional duty of recording the energy consumption of the customer. Through this channel, the utility company can retrieve energy consump- tion information, used for charging customers, or remotely interrupt energy supply for customers with overdue bills, for example. Additionally, preventive measures can be carried out by the control center based on data reported by sensors, such as triggering power supply unities when reports indicate an increase in demand. Smart grid thus offers multiple benefits to both customers and providers, including improved energy efficiency and reduced energy cost. Smart home has been a topic of growing interest in recent years [3]. In a smart home, ICT embedded into domestic objects enables ordinary tasks to be automated and remotely controlled, improving the quality of life of smart homes inhabi- tants. Despite sharing common interests and data, smart home 1 In this paper, the terms electricity network and power grid are used interchangeably. and smart grid typically work as two independent systems. Integrating smart homes and smart grid, though, offers new possibilities for both customers and utility companies. Through this integration, smart home devices can be configured to operate according to management parameters specified by the utility company, e.g. scheduling time-independent appliances to operate during off-peak hours. Additionally, information gathered from a smart home can improve responses of the smart grid, since the grid has richer data from customers and therefore can improve the management of resources at the utility company. Moreover, a smart home may offer the smart grid some indirect control to appliances within the customer premises. Through this control, the utility company could lessen peak electricity demands, leading to diminished waste of energy [4]. As the smart home communication usually relies on wireless medium, inherent vulnerabilities exist. Additionally, because smart home is typically comprised of devices with constrained resources, restricted protocols offering the bare minimum functionality to allow communication between de- vices are employed. In this scenario, defensive mechanisms found in traditional networks may therefore be not adequate in smart homes. Among many protocols developed for resource- constrained devices and networks, the use of Constrained Ap- plication Protocol (CoAP) over IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) emerges as a possible alternative [5]. Because both CoAP and 6LoWPAN are still in an early-stage of utilization, challenges presented by their employment in smart homes, specially with regard to security, still require further exploitation. This paper investigates the use of CoAP and 6LoWPAN as communication protocols for smart home environments. Both protocols are currently proposed standards of the Internet Engineering Task Force (IETF). We analyze the advantages of each protocol, as well as how smart home and smart grid environments benefit from their employment. We also provide an assessment of the different types of vulnerabilities that may compromise the operation of smart home networks based on CoAP/6LoWPAN. Finally, we present a performance analysis of the use of these protocols for ensuring secure communications in smart homes. This paper is organized as follows. In Section II, we review smart grid infrastructure, smart home scenario, and CoAP and 6LoWPAN. In Section III, we present a vulnerability analysis 2016 IEEE 30th International Conference on Advanced Information Networking and Applications 1550-445X/16 $31.00 © 2016 IEEE DOI 10.1109/AINA.2016.82 1027