Quantum computing holds the promise of improving cyber security infrastructure. Security algorithms such as those used in online banking require basic primitive operations such as factoring numbers. To improve security, larger numbers must be used resulting in a substantial increase in computational requirements.
Duncan Steel, professor of Electrical Engineering and Computer Science, Physics, and Biophysics at the University of Michigan, is developing quantum computer technologies in the context of cyber security. “These kinds of issues are critical,” Duncan notes, “If we want more protection, we need bigger numbers.”
In traditional computing, bits (0 and 1) are the atomic level of representation. In a quantum computer, quantum bits (or qubits) are the analog representation. A qubit takes on the value of 0 or 1, or a superposition of 0 and 1. That is, a qubit can assume a value of 0, 1, or any number in between.
Duncan analogizes the relationship of qubits as playing notes on violin strings. When a violinist plays a single note on the violin, a pure tone is produced. Equivalently, playing a second note producing another pure tone. If these two notes are sufficiently close on the musical scale and are played simultaneously, each notes are produced accompanied by the phase relationship between the two notes.
Instead of using wires to propagate information, Duncan and his team leverage lasers to manipulate information. Duncan notes the very delicate nature of manipulating qubits on the timescale of a trillionth of a second.
As the technology is relative immature, Duncan doesn’t anticipate the integration of quantum computers into desktop or laptop computers. Quantum computing, Duncan remarks, are built for factoring numbers and not for general applications such as video games.