English vs Bangla medium: How does it impact your career? While bits or binary digits are the building blocks of classical computing, quantum computing uses much more efficient subatomic Qubits for calculation. This is what makes them so much faster. Trending Latest Video Free. Now Mark Webber at the University of Sussex, UK, and his colleagues have investigated how large a quantum computer you would need to break bitcoin, in terms of the number of qubits, or quantum bits, the equivalent of ordinary computing bits. January 28, - pm Research. Comparing classical computers and supercomputers with quantum computers would be like comparing bicycles to motorcycles.