Demystifying Quantum Computing | Fundamentals & Security

Though it isn’t possible at the moment to break strong encryptions, it doesn’t mean  we will never be there
Demystifying Quantum Computing | Fundamentals & Security
Representational Pic

Imad U Din Ahmad

Imagine a world where we could simulate exact biological processes, chemical reactions and molecular bonding to create, and accurately test drugs. A device which might even have the power to unravel the secrets of the cosmos.

This is the power of Quantum Computing, a limitless ocean of knowledge which might otherwise have been unfathomable to humans.

What is Quantum Computing? A Brief History ?

In 1927 a group of 29 most brilliant minds were together in Brussels for the first time to discuss about the foundation of everything. The problem at hand was whether the universe at the minutest level works as a fundamental system or a set of probabilities.

After the Double Slit Experiment it was clear that light exhibits a wave nature, however, there were other experiments which stated otherwise. So, it was soon realised that the nature of light is actually a wave of probabilities and it is only when we check its nature it then exhibits one or the other nature depending on how we check it. This revolutionary discovery naturally rose questions about the then accepted nature of other known particles such as electrons which led to the Uncertainty Principal and thus eventually Quantum Mechanics was born.

How does a Quantum Computer work ?

Quantum computing works on the basic principal of using the power of endless set of probabilities exhibited by sub-atomic particles. In our traditional systems we use bits to store data, these binary bits are either off or on in other words a 0 or a 1. However, in quantum computing we use sub-atomic particles such as electrons, ions or photons to store the data which can be later manipulated just like a bunch of bits are used to make calculations. The bits in a quantum computing system are called qubits. So a qubit is the basic unit of quantum information. All the data of a Quantum computer is stored in a qubit chip and the majority of other components just comprise a highly efficient super cooling system. This is required as the qubits are highly sensitive and can easily get interfered by its surroundings such as heat or other particles; thus is kept at a near 0 kelvin in a magnetic field.

One of the phenomena qubits use is super-position which means they are continuously spinning between 0 and 1 and exhibit one of the two only when we check it. So, If in a traditional 3 bits system we get 3 bits of information, if we use 3 qubits we can get 8 bits of information simply because of the power of super position. The Information that can be obtained from qubits increases exponentially as we increase the number of qubits. IBM’s Osprey holds the current record for the largest quantum computing system with a processor that contains 433 qubits. Another important principal that Quantum computers use is Quantum entanglement. This phenomenon basically is when multiple object such as a pair of electrons, ions or photons share a single quantum state. This can be used to efficiently manipulate and transcribe the data stored by the quantum computer.

How do we communicate with a qubit ?

Quantum computers won’t simply work with our traditional assembly line firmware, thus a special assembly line software is used to interact with the qubits. Big tech firms are actively building such firmware which can be integrated with existing technologies so that we can develop various softwares that can be then powered by a quantum computer. Python is one of the languages actively used to build softwares and implement algorithms on a quantum computer firmware.

Also the moment we check the state of the qubit it loses its super-position power and the result is simply a set of data containing 0s and 1s. Although this at first seems like a problem as we can’t observe the super position state itself. This is solved by using special quantum algorithms that use probabilities of the super-position to perform calculations and then output a usable state that can be read.  So because of this requirement of probability factors, it means that a quantum computer won’t always be faster than a traditional system to solve some simple problems. However, it can solve enormous problems with a lot of variables in a fraction of time as compared to our current systems. One such example is the traveling salesman problem where we have to compute the best route a salesman can take to travel through multiple cities and end up at the same city he/ she started from.

This problem is quite hard for a traditional computer to compute as they have to go through all the possible routes one by one to find the best route, given the number of cities is quite large. On the other hand a type of Quantum computer called the Ising Machine can solve this problem in mere seconds by using a collection of qubits calibrated in a way to represent the distance between the cities and because of the quantum interaction they will all synchronise to the lowest energy state showing the solution which can be read to obtain the best route possible.

Will Quantum Computers break the Internet ?

Now the biggest question about quantum computers is that will it break our current systems. So while theoretically it is possible to even break AES encryptions using a quantum computer in minutes. It, however, isn’t possible with the given number of qubits right now even if Shor’s Algorithm is used.

What is Shor’s Algorithm ?

The encryption of all private Information sent over the web immensely relies on one numerical phenomenon that is; it’s quite hard to find the factors of a really big number especially if its factors are quite large prime numbers itself. The usual way is to brute-force all possible combinations but with a large encryption key size this task requires humongous resources and a lot of time thus deterring attackers from trying such attacks. But using the Shor’s algorithm; it starts by taking one random number which isn’t a factor and use it to improve the next guess and with every failed guess use a better guess in the next round. Then by analysing the results of all failed guesses it finds the factors with much probable guesses.

Although this process is also a type of brute-force it takes significantly lesser time to guess the factors than bluntly trying all combinations. Shor’s algorithm uses a concept to find shared factors of the large number by multiplying the prime numbers with itself enough times to get a number which can be used to find a shared factor. Finally if we divide the large number with the shared factor using this method over and over again, we break the factors of the very large number and break the encryption. We can also implement this algorithm on a traditional computer as well, but on a quantum computer it takes a fraction of time to find these factors.

Armageddon: Are there any Security Protocols that are safe ?

According to the Kryptera researchers, breaking AES-128 encryption should require a quantum computer with 2,953 logical qubits, while breaking AES-256 would need 6,681 qubits. Then there is the Shor’s algorithm, which can break asymmetric encryption with twice as many qubits as the key size. So to break an encryption with a key size of 256 bits will require a 512 qubit Quantum Computer using Shor’s algorithm while as we are still only at 433 qubits at the moment.

In the meantime security researchers are working towards making security protocols such as Crystals-Kyber Algorithm which can withstand the ravaging power of quantum computation. While as, Tech companies like google are also quite ahead in the race by launching security keys like FIDO2 and have announced that they are already working and experimenting with various other quantum attack resistant security protocols. With all that being said, in cybersecurity we say “Nothing is a 100% secure” so avoid sharing something digitally that you want to keep confidential.

Even-though it isn’t possible at the moment to break strong encryptions, it doesn’t mean we will never be there, big tech firms such as IBM already have announced to work on building a quantum computer with tens of thousands of qubits. If and when that happens, will the human race open Pandora’s box or become a super-civilization is yet to be seen.

The author is currently doing his Masters in Computer Sciences, Cybersecurity at Denmark Technical University. He is founder Dusksecurity Private Limited.

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