The IoT establishes a connection between objects in the real world and insert intelligence within the system in other for it to smartly process information pertaining to a specific object and make helpful automated decisions (Huang and Li, 2010). Hence, IoT can give rise to a large number of helpful applications and services never imagined before (Khan et al., 2012).
As the world continues to improve in technology, the processing strength and storage capability of devices increases while their sizes reduce. These smart devices can communicate via the internet and they are usually built with various types of sensors and actuators. Furthermore, physical objects become equipped with RFID tags that can be scanned with these smart devices. Unique identities will be assigned to these objects and the information relating to them will be inserted in their RFID tags.
Basic IoT system implementing different types of services
The main system of IoT can be simplified as follows:
1. Sensing objects, identifying of objects and communicating the object related information – Data that is sensed e.g. motion, acceleration, humidity, temperature, to mention but a few, depending on the sensor that is used, are regarded as the information. Merging various sensors can give rise to the design of a smart service.
2. Cause and action – The collected information pertaining to a specific object is processed by a smart device/system that decides on which automated action will be executed.
3. Bountiful services are provided by the device/system as well as a mechanism which provides feedback relating to the current system status and the result of the executed action to the administrator.
TECHNOLOGY AND COMMUNICATION AMONGST VARIOUS INTERNET OF THINGS (IoT) DEVICES
An automated data exchange amongst systems or devices is the primary aim of the Internet of Things. Described below are some specialized communication technologies through which the automated exchange of data amongst devices or systems occurs.
Wireless Sensor Networks (WSN)
According to (Akyildiz at el., 2002), Wireless Sensor Networks are setup from large numbers of sensor nodes with limited communication frequency and bandwidth. A basic Wireless Sensor Network is made up of the following communicating nodes:
IV. Radio Transceiver
Because of the limited scope of communication of the sensor nodes that make up the WSN, a multi-hop relay of information occurs between the origin of the information and the base of operation (Borgohain, Kumar and Sanyal, 2015). In collaborating with the different nodes, the needed information that is received by the sensor is then forwarded to the sink node for supervised routing to the base of operations (Shen and Liu, 2011). Wireless radio transceivers are used to form a dynamic communication network to aid the communication of data between nodes. Multi-hop data communication requires various nodes to take different traffic (Shen and Liu, 2011).
Radio Frequency Identification (RFID)
In relation to the Internet of Things framework, the primary use of the RFID technology is to automatically interact information tags with each other. RFID tags have no need for alignment or physical contact in its use of radio frequency waves to mutually interact and exchange data, it operates with the Automatic Identification and Data Capture (AIDC) wireless technology (Borgohain, Kumar and Sanyal,2015). The RFID has two components:
RFID tags (transponders)
There is a microchip inside of RFID tags. In addition, it has a memory unit that holds a unique identifier referred to as Electronic Product Code (EPC). The capability for the tag to be recognized universally is a function afforded by the EPC due to the universal numerical data it gives (Borgohain, Kumar and Sanyal,2015).
According to the classification in (Shen and Liu, 2011):
This tags EPC remotely communicate with other EPCs around it within a limited distance. Its inbuilt battery aids this communication.
The EPC of this tag only relay information when it is activated by a transceiver from within a limited range of the tag. An electromagnetic signal given off by a tag reader through inductive coupling as a source of power is used instead of a battery.
RFID tags work in partnership with tag readers – The EPC that identifies the RFID tag is scanned by the tag reader.
RFID readers (transceivers)
The role of the RFID reader is to detect the identification of each RFID tag based on its interaction with the EPC which it scans.
IoT SECURITY CHALLENGES
Based on the fact that IoT is an integration of multiple heterogeneous network, compatibility issues are expected to occur between different networks that are liable to security problems. Security problems like DOS/DDOS attacks, forgery attack, heterogeneous network attacks, to mention but a few, disturb the transport security of the IoT (Jing at el., 2014). Additionally, network congestion can easily occur in the core network because of the enormous amount of data during transmission (Jing at el., 2014). Furthermore, access to information and authentication of user, information privacy, destruction and tracking of data stream, to mention but a few, are some of the application security problems (Jing at el., 2014).
To achieve the purpose of analyzing the IoT security issues in more detail, the IoT security architecture is broken down into three layers according to (Jing at el., 2014): perception layer, transportation layer and application layer.
Proposed security architecture
The perception layer uses technologies like RFID, WSN, RSN, GPS. It is basically concerned with the retrieval of information, object perception and object control (Jing at el., 2014). This layer has two parts:
I. Perception node – It deals with data acquisition and data control.
II. Perception network – It deals with transmitting received data to the gateway or transmitting control command to the controller.
The following are detailed analysis of the security issues for the technologies used in the perception layer.