The chapter obj ectives are to describe the distributed ledger technology and

blockchain, compare blockchain and distributed ledger, describe their

benefits, explain blockchain formation, and what makes it special. Further,

blockchain types, integrity, conflict, and its resolution, fork, and its types

are described. The knowledge of the j ourney of blockchain is provided. The

blockchain versions are discussed together with the Blockchain 3 .0

Directed acyclic graph. Security connects, blockchain benefits and

limitations, and the various terminologies used are discussed next.

Introducing distributed ledger technology and

blockchain

A distributed ledger is a specific implementation of “shared ledgers”,

which are defined as a shared record of data across different parties.

Based on whether the network participants need permission from any entity

to make changes to the ledger, they are categorized as permissioned and

permissionless.

The nodes are network participants in a distributed ledger network and

depending on whether the ledgers can be accessed by anyone or only by the

participating nodes in the network, they are categorized as public or private.

The companies use a database that is centralized and lives in a fixed

location, wherein they have a single point of failure. However, a database

that exists across multiple locations or among multiple participants is a

distributed ledger.

A distributed ledger is decentralized for eliminating the need for a central

authority to process, validate or authenticate transactions and companies

use it for any kind of data exchange. U pon reaching a consensus by the

parties involved, these records are stored in the ledger.

Timestamping is done, and a unique cryptographic signature is given to all

files in the distributed ledger. All of the records can be viewed by all of the

participants on the distributed ledger, and a history of all information stored

on a particular data set is provided by technology for the purpose of audit

and verification.

The core attributes of the DLT based infrastructure are as follows: