Systematic study on vulnerabilities, countermeasures and security analysis tools for cryptocurrencies and post quantum cryptographic approach to design quantum resistant blockchains

Blockchain and other Distributed Ledger Technologies (DLTs) have evolved significantly in the last years and their use has been suggested for numerous applications due to their ability to provide transparency, redundancy and accountability. Public key cryptography and hash functions provide security to blockchains, smart contracts and cryptocurrencies. Fast progress in Quantum computing presents significant threats to blockchain systems as it has leveraged possibility of attacking cryptosecurity systems in near future forcing re-design of blockchains to withstand quantum attacks and vulnerabilities. This article studies different types of vulnerabilities to blockchains, existing countermeasures for attacks and investigates causes and preventive mechanisms to make quantum resistant or quantum proof blockchains. Thus, this article seeks to provide a broad view on security analysis tools, quantum-based cryptosystems, signature schemes and algorithms on Post-Quantum Blockchain (PQB) security to future blockchain researchers and developers.