LARGE-SCALE The number of devices will be far larger than the current Internet. HETEROGENEOUS AUTOMATED INTEGRATED WITH PHYSICAL WORLD Devices are based on a variety of platforms and communicate using different networks. Devices may be unsupervised for extended periods. Many might have zero or limited user interfacing. IoT connects the virtual world directly to physical objects and environments. Figure 2: IoT Characteristics It is clear from the above definitions that IoT deals with uniquely-identifiable, resource-constrained devices that measure and possibly control their environments and communicate over networks. We therefore exclude devices that are primarily intended for human interaction, such as mobile phones and computers; having said that, the extensive work done on IT security (or computer security 37) over the past few decades provides useful fundamentals for IoT security. IOT DEVICE AS A RESOURCE-CONSTRAINED DEVICE A representation of a generic IoT device is shown in Figure 3. IoT devices are extremely varied in nature and may consist of some or all of the components depicted. All IoT devices include sensors to collect information from the environment: these might be temperature sensors, motion sensors, air quality sensors, or light sensors, to name a few. Some devices may contain actuators for moving or controlling a system or environment. Devices also contain power supplies, often batteries. There is necessarily a module that provides connectivity, although the nature of this connectivity varies widely. There is also a certain amount of processing power provided by a microcontroller Operating system Application Storage Processing Connectivity Sensors Power supply Actuators 2.2 18 37 https://en.wikipedia.org/wiki/Computer_security Figure 3: An IoT Device unit (MCU), storage such as non-volatile RAM (NVRAM), and often a minimal operating system (OS) and a dedicated application.