# Physics is Taking Over

The power of quantum computers and what to expect from them.

Quantum computing: you may have heard the term quantum within the field of physics, but where does it fit into the world of computers? McKinsey and Company have an interesting analogy that is worth sharing as an introduction. Imagine flipping a coin; the options you have are heads or tails. When this coin is spinning, there is some probability that both of these options could occur. What if there was a machine that could interpret all of these optionsâ€¦

Classic computers, used in pretty much all technology, work on bits: the smallest increment of data on a computer. A bit, also known as a binary digit, is always in one of two physical states: zero or one. An easier way of understanding this is the childhood pleasure of balancing a light switch. Unfortunately, no matter how hard we would try, it would never work; it would always either be one state: on or off. That is the exact same as a bit: it is always a zero or a one.

Quantum computers are built on quantum bits or qubits. These can store zeros, ones, and everything in between. This feature is called superposition. Qubits behave in a way that is studied by quantum physics. This field investigates matter and energy at the most fundamental level to uncover the properties of the very building blocks of nature. Qubits, therefore, have some extremely special characteristics that do not compare in any way to classical computers.

Whilst classical bits are independent of each other, qubits can work under a state of entanglement which means the states of qubits can be correlated with one another. This means that the processing power of these computers is much more complex leading to its potential to seriously support advances in all fields of quantum study.

What is the future for these machines? Well, one aspect of them is something that has been colloquially named Q-day. This is the day that all data that is currently encrypted could be very quickly compromised. Encryption works by encoding plaintext which can be anything like your personal information held by a bank. Ciphertext, which is typically composed of cryptographic mathematical models, then encrypts the data. The ability to view the plain text again would need a decryption key to switch the ciphertext back to plaintext.

Quantum computing technology, being much more advanced, would be able to get through all of these mathematical models; anything that seems safe now will no longer be on Q-day. The Biden Administration in 2022 released a national security memorandum discussing a myriad of national and international security issues which included the cybersecurity threat of quantum computers. Generally, there was a fear that, in the wrong hands, this technology poses an imminent threat to global security.

Due to this, many nations are investing in these technologies in preparation but also for their computational efficiency. The Ministry of Defence purchased the government's first Quantum Computer on the 9th June 2022. The US is home to the Osprey; a 433-qubit quantum computer, the world's most powerful one to date.

There are of course fears that these computers could cause a geopolitical nightmare that would remove the idea of privacy from existence. Ethics boards are trying to get their heads around how this technology could impact the world but realistically, that answer is still up in the air. It will be interesting to see what mention of this technology occurs at the AI conference in Bletchley Park. We are yet to understand the full potential of these computers as we still do not really know their full function. It's a topic that is worth following as, in the near future, these developments could become mainstream.

*Image from WikiCommons*