Physical Review A. Quantum-based cryptographic systems could, therefore, be more secure than traditional systems against quantum hacking. One of the most overlooked problems of blockchain systems is their ability to resist the fast-evolving machines known as quantum computers. However, any measurement can be deferred to the end of quantum computation, though this deferment may come at a computational cost, so most quantum circuits depict a network consisting only of quantum logic gates and no measurements. Related information.