Blockchain: A Crypto-Intensive Technology—A Comprehensive Review

Blockchain has shifted the paradigm of computer-based commercial applications during the last decade. Initially developed as a public ledger for Bitcoin transactions, it has already shown that it has the potential to revolutionize the world, where trust, security, privacy, and anonymity are the assurances. The data stored within the blockchain remains unchangeable, resistant to tampering, and distributed across multiple locations within a decentralized network. The existence and reliability of blockchain rely heavily on robust cryptographic primitives, as these are fundamental to its operation. While blockchain faces significant challenges in the ever-evolving landscape of hardware and software technologies, it has retained its reputation for being secure due to its underlying cryptographic primitives. The architecture of blockchain, various consensus protocols, and the impacts of quantum computing are also discussed here. This study reviews the existing academic literature on cryptographic primitives used in blockchain and endeavours to bridge the gaps and provide a detailed understanding of their role in blockchain security. An exploratory qualitative research methodology is used in this study and is based on the latest literature on the topics. The findings of this study provide a valuable reference to the knowledge body and enhance the comprehension of blockchain, cryptography, and cryptographic primitives in blockchain for both new and experienced researchers, enabling them to identify new opportunities and challenges in the domain.