## 1 Introduction  
The number of things that are connected to the Internet is growing considerably. Because of this, a new concept, called IoT (internet of things) is emerging [1]. The IoT is a developing research area that has technical, social and economical significance. Technical significance results because IoT potentially enables us to connect, manage and control devices on the Internet, which were previously unconnected. The social significance is because interconnection of so many things will result in a multi interconnected smart world, in which many of the machines and the elements around us will be communicating with each other without any kind of human intervention. This certainly has the potential to improve the quality of human life. Lastly, the economic significance of the IoT is because it could be the largest driver of economic growth and employment in the next decade. The IoT is further divided into subclasses like; IoVT (internet of video things), IoRT (internet of remote things), IoV (internet of vehicle) [2], IIoT (industrial internet of things) etc. The work reported in this paper comes under the IoT subclass of IoVT and IoRT [3; 4]. Things equipped with a camera sensor stand out from other things due to the potentially sensitive nature of information and high bandwidth requirements for the video stream transfer. Thus, a subclass of IoT called IoVT was introduced, which addresses interconnection of things with cameras as sensors [5]. While the IoRT addresses things distributed over the wide geographical area [6], which in many cases do not have a terrestrial link to the Internet, but have to rely on satellite communication instead. Lack of implemented security on interconnected devices makes the IoT a darker world of surveillance; because in the IoT environment everything is potentially accessible through the Internet. So, ensuring information security on the Internet is very important to build trust in the use of Internet enabled devices. If people believe that their connected devices and their information on the Internet are not secure from misuse or harm, then they will be reluctant to use these devices. On the other hand, it is crucial that enabling information security does not significantly alter performance of the overall IoT systems. As security in the IoT is an important aspect, ranging from the technological issues to the more philosophical ones, such as trust and privacy, the security threats in the IoT can be divided into two categories [7]: physical attacks and non-physical attacks. The physical attacks are related to the physical nature of the things that are usually deployed in the public areas and cannot be constantly supervised like: cloning of things, malicious substitution of things, firmware replacement attack and extraction of security parameters. The non-physical attacks are related to the threats when the things start communication with each other like: eavesdropping attack, man-in-the-middle attack, routing attacks and denial of services. Protection from eavesdropping attack is in focus of this paper. In recent years, devices with integrated micro controllers, referred to as \"things\" in the IoT lexicon, are being transformed from simple and low-power devices to complex devices which often utilise power-hungry sensors (e.g., cameras) and possess complex hardware architectures (e.g., based on field programmable gate arrays; FPGAs). The main advantage of FPGA platforms as compared to ASIC (application specific integrated circuit) platforms is flexibility, which makes an FPGA a popular platform in IoT [8]. This makes the FPGA easy to interface to, for example, temperature, pressure, position, acceleration, ADC and DAC converters, etc., which is of great importance to IoT devices since these interfaces are frequently required by the \"things\". Another reason for using the FPGA in IoT is that the IoT devices have long life spans. Manufacturers may stop developing and rolling out software patches for a product once it reaches obsolescence.