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Blockchain versus IOTA Tangle

be objects of the physical world, including cameras, robotic actuator arms, light bulbs,

fans, air conditioners, etc. Or, they could be of the information or virtual world, such

as network packets, bits of data, biometric data and so on. These things are recog­

nized and integrated into a communication network with their unique identifiers. The

associated information possessed by these things could be static or dynamic.

The integration of sensor and radiofrequency technologies makes IoT a distrib­

uted network based on the omnipresent Internet hardware resources (Han et  al.,

2012). IoT as an emerging technology comes on the heels of such computing fields as

communications networks and global roaming technologies, involving the addition

of sophisticated technologies such as remote communication, remote data transmis­

sion technologies, sea and earth measures information, intelligent data analytics,

control technologies and DLTs.

The evolution of IoT is due to the convergence of various technologies in place

today. Such technologies include wireless communication networks such as the

4G and 5Gs, satellite communications systems, wireless sensor networks (WSNs),

embedded systems, offices, smart home automation systems, commodity sensors,

etc. More recently, machine learning, DLTs (blockchain, IOTA) and real-time data

analytics have come to play significant roles in the IoT ecosystem (Gupta et. al, 2020;

Petiwala et. al., 2021). The International Telecommunication Union (ITU), which

started a global standard initiative on IoT (IoT-GSI), defined IoT well in 2015 in its

Reference ITU-T Y.2060 as “a universal structure for the information systems, per­

mitting progressive facilities by interrelating both physical as well as virtual things

on the basis of prevailing and growing interoperable informative and communica­

tion technologies” (Dabeesing, 2017). This standard recommendation implies that

through identification, data capturing and processing capabilities, IoT should be able

to make full utilization of things to provide every kind of service to users for con­

firming security. IoT technologies enable objects prepared with sensors, actuators,

processors and transceivers to communicate. However, security and privacy are still

a concern to the IoT ecosystem, and this is where DLTs’ role is critical.

16.2  DESCRIPTION OF BLOCKCHAIN AND IOTA ARCHITECTURE

The two distinguishing features of the IOTA Tangle from the blockchain are: first,

the IOTA is fee free, while blockchain attracts network charges; second, the block­

chain employs miners, while IOTA does not. These two DLTs use different data

structures and consensus protocols. A brief description of the data structures and

consensus protocol is necessary to drive home the distinguishing features.

16.2.1  Data Structure

The data structure is how data and assets are stored in the computer for efficient

manipulation. Blockchain employs a hash-graph sequential data structure to attach

transactions to a chain. When the miners validate a transaction, only one block is

added to the chain at a time; see Figure 16.2. Consequently, this results in a block­

chain bottleneck, which is the reason for the slow TPS in many cryptocurrencies like

Bitcoin today.