IoT refers to the Internet of Things. The Internet is connected to any device (including cell phones, cars, home equipment, and other wearable devices integrated with the sensor system) so that they can exchange information with each other over a network. The concept of the Internet of Things (IoT) as a network goes back to the 1980s, from where it took momentum later on to become the future of the internet. Over a couple of decades, we have seen diversified technologies in communications emerging and reflecting upon different applications and their requirements as they satisfy the needs of both personal and commercial use.
Internet of Things (IoT) Connectivity Landscape
The Internet of Things (IoT) landscape now involves an intense variety of accessible connectivity alternatives that need to be harmonized first across various sectors and then correctly coupled to fulfill the IoT Technical Key Performance Indicators. Internet of Things technology is commonly used in intelligent homes, smart cities, transportation, and cars where each element is attached via a network to another. Radio frequency identification technology and wireless sensor networks are among the first form of connectivity used for IoT devices. Because of great application and implementation scenarios, IoTs achieved a lot of momentum in both the commercial and consumer market. The momentum gained by the IoTs led the standard developing organizations to put effort into the development of IoT solutions. Among the first proprietary solution, consist of Z-Wave and wireless-HART, which delayed the growth IoTs in the start due to interoperability issues faced by the vendors. After the setback, the Standards Developing Organizations started developing generic technologies such as 3GPP, IEEE, and IETF capable of connecting easily to previously constrained devices. Furthermore, IEEE802.15.4 along with Bluetooth are some of the famous low power short-range solutions that enable the IoT to expand further. Moreover, the 3rd Generation Partnership Project (3GPP) is contributing towards the support of the M2M application that works on 4G networks with the aim of embedding it into the 5G network. Not a single among those technologies has become a market leader, primarily due to technological shortfalls and uncertainties regarding business models. Now, as of the deployment of 5G is in its final phase to be available commercially for consumers the field of IoT has reached a turning point where promising emerging radio technologies contender to M2M such as Low-Power Wide Area, Low-Power Wi-Fi networks, and many improvements for M2M cellular systems. The most common aim of developing an IoT device is its availability and reliability, which these aforementioned solutions can provide. This section will further discuss IoT connectivity and simplifying the details of the recent and upcoming technologies that would have an impact on enhancing the IoT for the future.
1. Bluetooth Low Energy
The Special Interest Group (SIG) of Bluetooth proposed BLE in the Bluetooth 4.0 specification in 2010, which now has a version of 4.1. BLE is an intelligent Bluetooth low energy version, designed for communication in mainly short distances i.e. up to 50 m, and is primarily suitable for low-power applications such as entertainment, automotive and home automation as well. BLE works in the 2.4 GHz Industrial Scientific Medical Band (ISM), defining 40 channels and spreading 2 MHz BLE uses only 3 advertising channels for device discovery, connections and broadcast transmission in order to ultimately achieve low power use. They have been designated for center frequencies to limit disruption with channels 1, 6 and 11 of IEEE 802.11 used by many countries. All other 37 data channels aim to exchange data between connected devices in both directions. A frequency hopping adaptive algorithm is used over data channels to reduce interference sensitivity and multi-path decay. At present BLE supports only a single hop topology that is piconet, with an interface to communicate with several slave nodes and the broadcast group topology. BLE is intended as a key technology for certain short-range Internet applications such as medical care, intelligent energy and intelligent home applications. Since its early birth its potential has been identified, as shown by its rapidly gaining interest in IETF, where the 6LoWPAN Working Group (today 6lo) developed a requirement to allow IPv6 packets to be transmitted via BLE.
2. Zigbee
Zigbee is among the wireless mesh network, which is used in Wireless Sensors Networks for monitoring and control having low power and low cost to deploy. This technology is based upon the IEEE 802.15.4-2006 Medium Access Control and Physical standard specifications. From a physical layer perspective, current draws are determined by the hardware implementation and the energy required to transmit a given bit of information. On the other hand, it is realized that only many of the IoT devices exchange a few bits.
3. Low Power Wi-Fi
In its first edition in 1997, the IEEE 802.11 standard, better known as Wi-Fi, was published and intended without IoT in mind. Indeed, its ultimate goal was to provide a restricted amount of machines (called stations) situated indoors at a brief distance from each other with elevated throughput. Moreover, these days due to the large energy utilization Wi-Fi has not been implemented in instances of M2M-IoT compared to other norms. In comparison, the Bluetooth having a lower propagation range offers minimal power consumption whereas the ZigBee as discussed above has a large range with a lesser data rate. Energy limitation is among the major concerns in the application of IoT use cases which certainly impacts the battery life of a device. To overcome the issue of high energy consumption the IEEE802.11 community has put more focus on optimization of hardware that resulted in better energy-related solutions. On the other hand, even with the solution for low and efficient consumption, Wi-Fi still lacks in mobility and support for roaming. In regards to this, good quality of service is not guaranteed which is due to high interference when sharing the 2.4 GHz band along with ZigBee and other band devices. The use of sub1 GHz license-exempt bands having better propagation properties as compared to the traditional Wi-Fi bands has been proposed by the IEEE 802 Lan/Man Standards Committee (LMSC) to overcome interference issues. Furthermore, a task group knew a Low-Power Wi-Fi was formed by LMSC in 2010 which aimed of increasing the area of application of Wi-Fi networks to meet the IoT requirements. An access point in many of the IoT devices and applications has to cover many of the sensors that are responsible for the transmission of packets from time to time. The limitation of the number of stations that can be combined with the same AP is one of the principal challenges to the adoption of the former IEE802.11. We overcome the limitation by adopting IEEE 802.11ah standard, introducing a hierarchical method that defines groups of stations and further allows to support a greater number of devices.
4. Low Power Wide Area
The LPWA technology is newly developed specifically for low-end IoT applications that require low-cost devices, a long lifetime of batteries, and small amounts of data, a field that traditional cellular M2M devices have not been optimized for. The word LPWA, brought to the industry by Machina Research, means high-level wide area networks with small prices and small power. It operates in a non-licensed range and is currently available in a variety of proprietary solutions, mainly for M2M networking. The main characteristics of LPWA can be summed up as Wide area coverage, longer battery life, low bandwidth communication, and low-cost communication. The latter limits the LPWA application range to a number of M2M cases, which are characterized by low data rates and unusual transmissions. LPWA does present some downsides despite its attractive and exciting characteristics, primarily because of the use of non-licensed range to communicate with long distances. In that portion of the license-exempt range, efficient radiated energy (ERP) is strongly controlled with regard to permissible transmitting forces (after signal increase), service periods, and entry processes. As bases and mobile antennas have completely distinct profit capacities, up-and downlink connection capacities are skewed and the uplink has a link budget of up to 19 dB. While the European legislation permits an improved downlink capacity of 13 dB, there continues a distinction of at least 6 dB, thus not ensuring a genuinely symmetrical connection. Furthermore, simple operations, such as sending a recognition, cannot be carried out without any problems as in 3GPP techniques. Therefore, this technology can only support a restricted number of IoT applications. Moreover, due to impending spectrum congestion, LPWA cannot meet the scalability demands of large IoT projects. Cisco IBSG forecasts that 50 billion internet-linked phones will be available until the year 2020 and among those will be utilizing some other radio technologies which share the spectrum with LPWA including Lp-Wi-Fi, ZigBee, and IEEE 802.11 g. The LPWA unit, with small receiver sensitivity for long-range communication, perceives all such transmission to be interference. Above all, LPWA is anticipated to be the main enabler for fast IoT deployments and restricted IoT applications.
Internet of Things (IoT) Security Challenges
Internet of Things (IoT) devices has become the target of security risks because of the fact that they have potential to distribute and spread the risks in greater number than the rest of the internet. A traditional IoT application includes diverse equipment with integrated sensors connected via the network. IoT devices are unique and distinguished mainly by low energy, limited memory, and restricted computing capacities. To adopt a secure IoT implementation, quite a few methodologies should be kept in mind.
- Data Privacy, confidentiality, and integrity – To guarantee the confidentiality of information, a correct encryption mechanism is needed as the data travels over a network through several hops. As the devices, services, and the network are integrated, the actual data stored on the device might be exposed to privacy violation if the nodes are compromised in the network. IoT devices vulnerable to attacks can help an attacker compromise data integrity and can modify already stored data for mischievous purposes.
- Authentication and authorization – Authentication between two parties that communicate with each other is needed to ensure IoT communication and above that devices must be authenticated for privileged access to services. The variety of IoT authentication mechanisms is primarily due to the various underlying, heterogeneous architectures and environments that support IoT equipment. Furthermore, this status presents a challenge to define the worldwide IoT authentication standard protocol. On the other hand, the authorization mechanisms ensure that access to systems or information is provided to the authorized ones. Sustainable deployment of authentication and authorization gives us a secure environment for communication between IoT devices.
- Service availability – A denial of service attack can obstruct the availability of services in IoT devices. In a distributed denial-of-service attack an attacker targets different layers of IoT devices by launching different attacks such as replay attacks to stop the availability of a system to its legitimate users.
- Single point of failure – A steady growth in IoT-based networks may reveal a big amount of single-point failures, which in turn may deteriorate the services provided by IoT. The construction of a manipulative setting for a wide variety of IoT systems and alternative mechanisms for implementing a defect-tolerant network is necessary.
Categorizing Security Issues
The IoT paradigm includes a broad range of systems and machinery from tiny integrated processing chips to huge, high-end servers so that potential security problems can be resolved at various rates. We can distribute the security concerns into two different levels
- Low-level security issues
- Intermediate level security issues
1. Low-level security issues
The physical and data link layers are mainly concerned with low-level security issues such as Sleep deprivation attacks and Jamming attacks.
- Sleep deprivation attack – IoT devices have energy constraints which suggest us that they are susceptible to sleep deprivation attack causing the sensor nodes to stay awake. Once the attack is successful it can result in battery deficiency when a greater number of tasks are set to be executed.
- Jamming attack – The jamming attacks on wireless devices in IoT by sending radio frequency signals without a particular protocol. This disruption of the radio signals majorly impacts the operations of the network communication problems between the nodes and eventually causing the system to malfunction. Moreover, the insecure initialization and configuration of the IoT devices at the physical layer results in violating privacy and disruption of the services provided by the system.
2. Intermediate level security issues
Intermediate safety problems are primarily related to the communication, routing, and session management of IoT network and transport layers.
- RPL routing attack – The IPv6 Low Power and Loss Network (RPL) Routing Protocol is susceptible to several assaults by compromised network nodes which could result in eavesdropping and depletion of resources. Furthermore, the sinkhole is used to perform malignant activity on the network. When a sinkhole attack is launched a routing request is addressed by the attacker node which results in routing the packets through the attacker node.
- Transport level security – The goal of the transport layer is to provide a mechanism of secure communication that results in data from the sender node to the receiver node is transferred in a reliable manner. Comprehensive and detailed authentication mechanisms are required to satisfy the transfer of data in encrypted form along with keeping the secrecy and privacy at all costs.
- Insecure neighbor discovery – In the development of an IoT architecture it is a requirement that each device in the network should be identified as unique. The message communication for identification must be safe to ensure that the data transmitted to the device reach the specified destination during the end-to-end communication. In the neighbor discovery mechanism, few steps are performed which include resolution of the addresses and discovery of router. Moreover, the implication of identifying neighbor packets with improper mechanisms could lead to denial of service.
IoT Security Solutions
IoT’s safety vulnerabilities include application/interface vulnerabilities, network elements, software, firmware, and physical devices, which exist at multiple concentrations. Users in an IoT paradigm communicate with these parts through protocols that can also be dismantled. Countermeasures are needed at each protocol level to deal with the specific threats. Furthermore, varied protocols which support the deployment make the countermeasures difficult to implement.
The interference causing message collisions or channel flooding is a jamming attack for the wireless sensor networks. To detect an attack an approach is used to measure the signal strength which can further be used to identify signals containing noise. Furthermore, to deal with sleep deprivation attacks a cluster-based approach can be used where we can divide clusters into different sectors. This will help us in reduced consumption of energy when we avoid communication-based on long distance. Authentication techniques are essential for the information as well as for the entity. An identity method framework management system has been proposed to achieve authentication. It suggests we allocate an identity manager that will ensure the authentication of the received data and will forward the data to the manager in charge of the service to allocate the services to be performed. Furthermore, protecting data traveling on the network is of extreme importance as the man in the middle attack could monitor and alter the communication as desired. To overcome the issue of ensuring the privacy of the data, a PKI-Lite protocol helps us to achieve the goal. This protocol suggests we encrypt the nodes that are traveling from sender to receiver and then using a key to decrypt the message. Moreover, the proposed methodology also suggests that the data we are sending should be transferred to an offspring node which further transmits the key to the receiver when the nodes arrive at the receiving end.