By Konstantinos Karagianni, Principal Consultant, Ethical Hacking
Classical computers that work with zeros and ones will soon join the abacus and UNIVAC on computer-history timelines. In this first instalment of a multi-part series, we’ll look at how binary beasts have just about reached their architectural limits, and how a truly strange creature—the quantum computer—may both overcome these limits and make possible advanced functions that could revolutionize information technology.
Chip makers won’t admit it’s time to panic, but we’ve hit maximum trace-shrink. Before long traces will have to be one-electron wide to allow for cramming more transistors into the miniature metropolises that are CPUs. And when we reach such an ultimate frontier of tininess, all digital hell will break loose.
The subatomic world of the quantum is not like the world of the large. Imagine sitting at the dinner table only to have your plate disappear and reappear in the next room. It might aid your digestion retrieving din-din, yet chasing a vanishing plate could mean you never take a bite. Likewise, having an electron vanish from a circuit trace would make it difficult to guarantee you end up with … well, bits and bytes. This could happen due to a phenomenon known as quantum tunnelling a particle has a probability (or wave function) of being in various places at any given moment. Make the spaces between circuit components too small, and the wave function will include a probability of having electrons appear within transistors or paths other than the ones intended. In the world of the quantum, probability does not describe a thing. Probability is the thing. Electrons and other particles can get around.
For now chip makers are compensating by adding more CPU cores. Samsung even announced an 8-core chip for phones at CES. This is a mere stopgap. Maintaining Moore’s Law and any further leaps in computing power will become impossible by relying on building devices with dozens of CPU cores.
To bypass the limitations of some aspects of quantum weirdness, we need to embrace other oddities such as superposition, which makes possible a new unit of information: the qubit. A qubit is in a superposition of both zero and one at the same time, as represented by a particle that can be in two states simultaneously. Examples of particle states are spin up and spin down, although it’s unnecessary to understand what spin actually is for our purposes. Superposition is delicate—observing a particle in this state causes de-coherence resulting in a concrete spin up or spin down (a classical 0 or 1). Unfortunately the universe is always making observations of particles by merely having them bump into each other, and a quantum computer will have to maintain superposition until an operation can be carried out.
If you can maintain superposition, however, you can bypass any worries of tunnelling and apply special algorithms to qubits, thereby performing amazing feats, such as slicing through encryption in seconds rather than centuries. Next time we’ll start looking at the algorithms made possible with quantum computing that will change security forever.
Hear more from Konstantinnos on this subject at https://www.ncsc.nl/conference on 22-23rd January.
To read the latest on ethical hacking from our Centre of Excellence, click here.