The world is experiencing a dramatic transformation as a result of the emergence of intellectual information technology among the main industries where high-end user engagement is anticipated to boost service qualities in all fields. Blockchain is one of the most brilliant technology enablers to overcome most of the current limitations and provide the functional needs of 6G. This chapter examines the importance of blockchain in tackling pressing 6G concerns as well as potential future applications and new research fields like artificial intelligence, data storage and analytics, and internet of everything. In addition to offering a solitary answer for application security and privacy, blockchain also has its own unique set of security and privacy flaws. This chapter examines the advantages, drawbacks, and possible routes for getting through the obstacles associated with using blockchain in 6G.
TopIntroduction
A blockchain may be described as a spreading technology in the framework of today's increasingly digital environment, where the accuracy, reliability & security of digital data are key issues in the wake of the global data revolution (X. Li, P. Jiang, (2017)). In a blockchain, a block is a growing collection of data that is logically connected to every other block by encryption, Figure 1. depicts its fundamental structure. According to (Vladimir Plotnikov and Valentina Kuznetsova (2018)), each block contains a timestamp (to verify the transaction's existence), a cryptographic hash (the hash value for each connected block is similar to a “digital fingerprint” that guarantees block confidentiality and is always unique for supplying encrypted data, durability & serviceability), and transaction data (including details with record).Transaction data is frequently represented as Merkle trees (Becker, G., (2008)) (Dhumwad, S., Sukhadeve, M., Naik, C., Manjunath, K.N. and Prabhu, S., (2017)). Because each block in a chain has information about the block that came before it and they all function together to form a chain, another benefit is data change resistance. Each block that comes after it strengthens its predecessor, severely restricting data alteration while remaining unaffected by any blocks that come after it. (Khacef, K. and Pujolle, G., (2019)) suggests peer-to-peer protocols are used to administer and control blockchain, which is primarily a publicly distributed ledger (Z. Li, A.VatankhahBarenji, G.Q. Huang (2018)). Blockchain is a publicly accessible & readily viewable distributed ledger where nodes use a procedure to validate and connect with new nodes. Blockchain technology does not require a centralized server or system to store data. Globally, there are millions of blockchain devices processing the dispersed data. On these computers, data can be notarized because it is easily verifiable and saved on each node. The three cornerstones of blockchain technology are decentralization, transparency, and immutability (Flovik, S., Moudnib, R.A. and Vassilakopoulou, P. (2021)). Blockchain - based information are exceedingly hard to attack because they have been encrypted. Additionally, hackers would need to alter the entire chain in order to alter a single record on a distributed ledger since every entry is connected to the entries that came preceding and following it.
Figure 1. Blockchain technology basic structure
Distributed ledger technology, Immutable records and Smart contracts are the main key-elements of blockchain technology (Peters, G.W. and Panayi, E. (2016)) (Bashir, I. (2020)) Where,