Security Challenges

Hardware is usually limited in terms of restricted computation, memory, radio bandwidth and battery resources. These hardware limitations mean that computationally intensive security tasks are generally not feasible, especially where a device is responsible for a heavy data stream 10.
These limiations can often be mitigated in applications where the physical environment is conducive to enabling greater power consumption and heat dissipation - such as a factory or vehicle 5.
The complacent attitudes of manufacturers, combined with a lack of understanding regarding cyber threats is another issue plaguing IoT devices1 . This can in part be attributed to the fact that IoT systems area relatively new and typically less understood than traditional iT systems 5.

Geographic Challanges

Systems are often deployed over wide geographic regions and in uncontrolled open environments5 . This can introduce vulnerabilities in the form of a single point of failure in the network compromising the availability and integrity of the entire network 3.
Such devices can include WIFI enabled security cameras, Bluetooth enabled hearing aids, or any number of WIFI and Bluetooth enabled smart home devices6.
This results in a wide range of use cases and infrastructure configurations that will have varied data and resource security requirements. Therefore, whilst it typically falls upon the consumer to protect their devices from physical threats and vulnerabilities such as theft, damage, and incorrect user operation1 ; it is critical that developers look toward working groups such as the ISO and IEC and their recommended frameworks 5.

Security Requirements

Assessment of security requirements based on the Confidentiality-Integrity- Availability (CIA) triad9 . Confidentiality implies that network data packets are not being intercepted or examined. Integrity refers to dynamic or static data being protected from unauthorised manipulation. Availability requires all devices to be functioning properly and in an uncompromised manner; free from any viruses, worms or malware.
IoT systems must address security issues such as denial of service (DoS) attacks, distrubuted denial of service (DDoS) attacks, jamming, man in the middle attacks, and malware5 . These threats can be largely mitigated by employing methods of authentication, access control, malware detection and secure offloading techniques10.

Blockchain Security Approach

At a higher level, blockchain technology is beginning to gain traction. This is because most IoT problems arise as a result of the IP protocol being the main standard for connectivity 4. Blockchain is a paradigm shift as it does not require the participation of a trusted third party for authentication purposes due to its de-centralised nature 7.
Integrity is maintained due to the recursive nature of the digital signatures in the ledger 5 . 'Smart Contracts' can also be established within the blockchain protocol. These contracts can be devined as "a computerised transaction protocol that executes the terms of a contract" 3.
In the context of IoT devices, smart contracts are required in order to handle queries and transactions proposed from the devices typically found within database applications such as query, create and update with regard to device information held within the ledger 3.