What does quantum computing do that regular computing can’t? In this article, I will answer this question. Spoiler; the answer is rather extensive. And here’s why.
Quantum computing relies on technology that is much smarter than current computers. This is because quantum computing uses qubits rather than bits. Quibits can hold multiple positions at once, as well as send information undisturbed over incredibly long distances.
As of now, quantum computing focuses on two major problems. The first is the undisturbed transmission of detailed digital information, and other is the future of cryptography with quantum features.
This article looks at a few of the central concepts that are relevant to understanding the future of quantum computing. We’ll examine how researchers take on these research problems.
So let’s take a closer look at the unique qualities of quantum computing: the superposition and entanglement of qubits.
Quantum Mechanics 101
Quantum computing is an off-shoot of the much broader field of quantum mechanics. It belongs to the framework of theoretical physics. This area of theoretical physics is the study of the smallest parts responsible for the movement of energy. This involves examining quantum states, which includes quantum particles or subatomic, which includes: atoms, electrons, and photons.
Therefore, quantum theories examine the most subtle concepts that underly the makeup of our universe. Quantum computing does something similar. It includes the analysis of the subtle underlying qualities that allow for substantial computations, which are qubits.
Basically, quantum computing will make substantial computations a reality. This is a total understatement of its potential. Once the theoretical potential of quantum computing is fully realized, it will change the way computational capacities and information is shared.
Qualities of Qubits: Superposition and Entanglement
Most of you reading probably know that traditional computers run on code made up of zeros and ones called “bits.”
Quantum computers function using the same basic principle as classic bits. But instead, they have what we refer to as “qubits.” Qubits are quantum bits that capitalize on the phenomena of “superposition” and “entanglement.”
Superposition and entanglement are really technical ways of saying that qubits are much more malleable and durable than the run of the mill bits that traditional computers run on.
Entanglement and superposition make qubits more flexible and extendable than a regular bit when transferring information. Why? Simply because even when we are using zeros and ones, with qubits, due to the great potential of states, there are more possible outcomes for combinations of zeros and ones.
Entanglement
Entanglement is the property that means the particles remain perfectly correlated. Even when they are separated by a great distance. Within a quantum understanding, particles are so intensely interconnected that they maintain unity and coherence even at opposite ends of the universe.
Superposition
Superposition is the ability a quantum system has to allow it to be in multiple states at the same time. If a computer uses superposition, the binary code can hold multiple positions and states at the same time. This makes the code much more malleable.
So, because of the qualities that qubits posses, they can actually “search” for better and worse ways to solve different problems. This is because the particles have such a strong connection to one another because of their property of entanglement. The particles of qubits prefer to remain in a state of unity. As such they are strongly drawn together.
And the quality of superposition means that the message remains intact in a variety of positions. This is helpful when sending information over a long distance, as the message will remain undisturbed.
Essentially, because of superposition and entanglement, a quantum computer can process more information and calculations faster. It can also perform computer functions simultaneously. This is simply because classical computers rely on the limits of ones and zeros. But if you’re using superposition of ones and zeros, quantum computing can solve problems much more efficiently.
Polarization and Photons
Another benefit of quantum computing is the unique measurability of photons, called polarization. A photon’s polarization measurements are not knowable in advance. However, the property of entanglement gives a quantum message the precious quality of long-distance coherence. Unfortunately, you cannot predict the measurement of photons because it is random. Entanglement ensures that the measurements of the same photon will remain the same until disturbed.
Let’s talk about why this is important for transferring information.
Alice and Bob receive and measure a quantum message. The entanglement of the photons means that when both Alice and Bob measure the polarization of the entangled photons they receive, they will come up with the same results. Alice and Bob then ascribe either a “one” or a “zero” to each photon they receive.
Because the polarization of the same photos will always have the same measurement, when they measure their results, if Alice gets a string like 010110, then Bob gets the same outcome.
Eavesdroppers and Message Corruption
However, although the particles of quantum messages have strong attractions to one another, they do not like to be disturbed. One of the major challenges to quantum computing is that qubits can be very difficult to manipulate.
As a consequence, if the qubits are disturbed by an outside force, or “eavesdropper,” they will fall out of their quantum state. This disturbance is called decoherence.
So, if Alice and Bob are measuring their photons, and do not have identical results, they will know that an eavesdropper is trying to spy on the signal. But if Alice and Bob keep receiving photons until their identical keys are long and identical enough and they have an ultra-secure key for encrypting communications.
Therefore, to remain undisturbed, photons must be isolated from all other information. This is the state of quantum coherence. Coherence is essential in order for a quantum message to survive undisturbed.
The delicate nature of quantum information is beneficial as a corrupt message is obvious. It also means that a quantum message can only be transferred, but never duplicated or shared.
Polarization does make quantum messages impossible to corrupt. It also makes qubits very tricky to manage and study closely. This is because any subtle interference will change the photons of a qubit.
Encryption and Large Number Factorization
One of the reasons that classic encryption is so effective is because it uses prime numbers and factorization. Now if you remember from high school, prime number factorization is very limited. This is because the prime number is a number that can only be divided by 1 and itself (2 is the smallest prime number).
Factorization computations are notoriously difficult for computers to do because there is no truly efficient way to factorize. Therefore, factorization is a computationally heavy procedure for regular computers.
For example, to factor a large number that is 500-digits, it would take a typical computer 1 billion years to solve for all of the prime numbers. However, with a fully functioning quantum computer (TBD) it would only take about 15 minutes.
This is a good news/bad news situation. The good news is that this kind of computational power makes solving for anything efficient. The bad news is that this kind of computational power makes solving for anything efficient.
Do you see where I am going with this?
Let’s have a look at how cryptography will be affected by quantum computing.
Classical Cryptography
RSA encryption is a classic form of encryption that relies on the factorization problem. Online stores use RSA to encrypt credit card numbers.
The websites you shop on will give you a public key, which anyone can access. The public key encodes your credit card information. The product of two very large prime numbers, that the seller knows, makes the private key.
So if someone wants to hijack your information, they need to know the two prime numbers that multiply to create the key. As I stated earlier, factoring is very hard, therefore, eavesdroppers are unable to access your credit card and banking number.
The “one-time pad” is a common cryptographic practice. Alice and Bob share a long, random, binary string; this is their secret key. They are the only ones who know what the key is if the key is only used once. And so they can safely transmit a secret message that no eavesdropper can decipher.
The biggest challenge with the one-time pad is the actual distribution of the secret key. In the past, Alice and Bob shared these keys manually. In the past, governments sent people to exchange books full of random data for private keys. This is system obviously is impractical and imperfect.
Enter quantum computing and quantum cryptography.
Quantum Cryptography
Bad news. As I mentioned, quantum computing will affect classical cryptography. When quantum computers overcome the problem of efficient factorization, then they will be able to decrypt classical encryption.
Good news! Quantum computing will also offer a solution to the limitations of classical cryptography. Quantum Key Distribution (QKD) makes the distribution of completely random keys at a distance possible.
Remember what I said about superposition and entanglement earlier? Large messages are shared over a long distance undisturbed as a result of these qualities. And, because of decoherence, if an eavesdropper tries to interfere, it will be clearly apparent. This will allow for Ultra Secret Keys (USK), where any attempt to observe or measure a quantum system disturbs it.
Current Limitations and Future Exploration
Decoherence:
Although qubits make it possible to take advantage of superposition and entanglement, they are also very difficult to control. Basically, we do not fully understand qubits at this point. Qubits could be made up of photons, atoms, electrons, molecules or even something else entirely.
In order to understand qubits, there is still a great need for additional research. Even despite the significant amount of research that is ongoing. Qubits are particularly difficult to manipulate. This is because of decoherence; any disturbance causes them to fall out of their quantum state.
Quantum error correction is a field of study that is currently examining how to avoid the problem of decoherence as well as other issues quantum computing faces. Nevertheless, researchers are very optimistic about the potential quantum mechanics and computing holds.
Quantum Computing Research and Development
Research studying quantum states has been around for a long time. Scientists havebeen developing quantum theories since the 1900s, trying to understand the different ways that energy is created and the underlying causes of energy’s movement.
The most notable researchers for modern notions of quantum mechanics are Richard Feynman and Peter Stor. Feynman is the theoretical physicist who founded the field of quantum computing and introduced nanotechnology.
Peter Stor is an American professor of applied mathematics at MIT. Shor is known for having developed Shor’s Algorithm, which makes factoring exponentially faster than the best-known algorithm running on a classical computer.
Presently, researchers at IQC at the University of Waterloo are researching a large array of them as potential bases for quantum computers. The University of Waterloo’s, The Institute for Quantum Computing is currently home to a world-class research team. With IQC as a world leader in quantum information research, Waterloo and Canada are referred to as “Quantum Valley.”
Why Quantum Computing Systems
- Superposition: Classical binary models do not set limits on quantum computing. There is potential for quantum computers to search for solutions, rather than be programmed to solve problems. Superposition makes is possible to run models more effectively, leading to any number of solutions in understanding chemical processes for pharmaceuticals to the application of superconductors. Superconductors allow for an electric current to loop through the superconducting wire. This can persist indefinitely with no power source.
- Entanglement and decoherence: The property of entanglement will make transferring information a long distance safely and completely uninterrupted a reality. And decoherence, once fully understood, will allow for the impervious security from eavesdroppers and attackers.
- Qubits: Because of the properties of qubits, a quantum computer is inherently faster than a classical computer at searching through a space of potential solutions for the best solution.
- Cryptography and factorization: Quantum computing will change the way that cryptography works, both cracking the problem of limited factorization and enabling the creation of more attacker resistant public keys.
Researchers are excited about the potential of quantum computing. Because once refined and fully operational, it will change the way computations are run. Once refined and fully operational, quantum computing will change information processing forever.
