The goal of post-quantum cryptography (also called quantum-resistant cryptography) is to develop cryptographic systems that are secure against both quantum and classical computers, and can interoperate with existing communications protocols and networks. Still, even with error-correction, large-scale, fault-tolerant quantum computers will need hundreds of thousands or millions of physical qubits. And other challenges—such as how long it takes to move and entangle increasingly large numbers of atoms—exist too.
Unlike a classical bit, a qubit can exist in a superposition of its two “basis” states, which loosely means that it is in both states simultaneously. When measuring a qubit, the result is a probabilistic output of a classical bit, therefore making quantum computers nondeterministic in general. If a quantum computer manipulates the qubit in a particular way, wave interference effects can amplify the desired measurement results. The design of quantum algorithms involves creating procedures that allow a quantum computer to perform calculations efficiently and quickly. Because of their sensitivity to environmental disturbances, quantum computers today are highly unstable and must be held in expensive refrigerators cooled to near-absolute zero temperatures.… Read More View More Quantum Computing for Portfolio Management and Investment Strategies