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Blockchain Technology

The features of blockchain benefitting IoT implementation are as follows (Khan

and Salah 2018):

Address Space: Compared with IPv6 with its 128-bit addressing system,

blockchain uses 160 bits for addressing, enabling the scalability of block­

chain solutions for IoT, considering the widespread usage of IoT that is

likely in the near future (Antonopoulos 2017). IoT devices face challenges

in implementing a full IPv6 stack with limited resources and hence, can

utilize the blockchain address space.

Governance and Identity of Things (IDoT): Identity and Access Management

(IAM) for IoT has several challenges that must be addressed to manage the

risks. The device may change hands during its lifetime from the manufac­

turer to the consumer, including dealers and retailers. The device’s owner­

ship needs to be managed seamlessly every time it is sold and resold (Khan

and Salah 2018) Blockchain presents an opportunity to address this chal­

lenge with its security features and capabilities (Otte et al. 2020).

Data Authentication and Integrity: IoT devices, if connected via a blockchain

architecture, would transmit data securely (cryptographically secured) and

with trust (digitally signed from sender using its unique public key and

GUID or Globally Unique Identifier). Moreover, blockchains provide better

auditability of the actions with the ledgers.

Authentication, Authorization and Privacy: Smart contracts can drive a

decentralized authentication and authorization in IoTs with a predefined

set of rules. Smart contracts are much more effective than the traditional

solutions available today.

Secure Communications: MQTT (MQ Telemetry Transport), HTTP

(Hypertext Transfer Protocol), XMPP (Extensible Messaging and Presence

Protocol) and CoAP (Constrained Application Protocol), including the rout­

ing protocols such as 6LoWPAN (IPv6 over Low -Power Wireless Personal

Area Networks) and RPL (Routing Protocol for Low-Power and Lossy

Networks) used by IoTs, have security concerns by design. These need to

be used with protocols such as TLS (Transport Layer Security) or DTLS

(Datagram Transport Layer Security) for security enablement. With block­

chain, the overhead of ensuring trust can be eliminated; the unique identi­

fiers and the trust model of the blockchain can aid secure communications.

A detailed list of IoT security requirements versus blockchain technology is

shown in Table 4.1 (Makhdoom et al. 2019).

4.8  DATA SECURITY IN IOT WITH BLOCKCHAIN

Data security and privacy are among the most sought-out topics today in security.

IoT devices, mostly sensors, often deal with sensitive or critical data that could lead

to serious security issues if tampered with or lost. Blockchain works on a different

trust model, which is decentralized. The full nodes and miners in a blockchain keep