Quantum Computing and cryptocurrency

Sanskruti Dube
GDSCVITBhopal
Published in
6 min readFeb 28, 2021
Introduction Image

Where had you come across the word “quantum” before? Predominantly in Physics or Chemistry, isn’t it? “Quantum” literally means a small share or portion of something. It refers to a discrete quantity of energy or any other physical quantity, such as momentum or electric charge in physics. Quantum Physics has already remodelled our lives as almost every other electronic device around us is a fruit of Quantum theory. Owing to this, we are probably heading towards a “Quantum revolution” shortly. This revolution has led to the rise of a new term called “Quantum Computing.” Let us see what this new term connotes.

What does the term “Quantum Computing” refer to?

Quantum computing implies using quantum phenomena such as superposition and entanglement to perform computation. Some tasks can’t be executed by classical computers owing to the complexity of problems. Some problems can take long periods of execution time as long as thousands of years! To outstrip these issues, “Quantum computing” arose. Quantum computers can perform such calculations which were impossible using classical supercomputers.

How do they differ from classical supercomputers?

The traditional classical supercomputers compute data based on binary digits called bits which consists of 0 and 1. This approach solely relies on “certainty” and precision. But with the high increase in the complexity of data, it fails to provide the necessary results within the stipulated time.

On the contrary, the quantum world works on the principle of “uncertainty” where the language probability comes to play. Here the computation of data is carried out in the discrete units called quantum bits or qubits. Qubits have some plausibility of being a 0 or 1 at the same time. This “superposition” of 0 and 1 is not a flaw, but a feature. It provides new means and more powerful ways to communicate and process data.

Applications of Quantum Computing:

1.Physiology:

One of the most significant applications of quantum computers is in creating simulations for the analysis of molecules in drug development and materials design. A quantum computer is eccentric for these as the simulations are based on the same laws of quantum theory in physics. The use of these quantum devices to simulate quantum chemistry gives more efficient and faster results than the currently used supercomputers.

2.Working with intricate data:

Quantum computers are perfect tools for solving complicated optimization tasks. They also serve as the best fit for executing searches of unsorted data at great speed. This can be implemented for many applications like sorting climate data, data related to health or finance, supply chain logistics, workforce, or traffic flow management.

3.Quantum encryption:

One of the biggest perks of quantum theory is its probabilistic nature. It ensures that the information cannot be precisely copied. From a security perspective, this is highly significant. Even if the hackers try to forge quantum keys used for encrypting and transmitting messages, they will get absolutely nothing except mere failure even if they had access to a quantum computer or other powerful resources. Thus, this fundamentally uncrackable encryption works on the laws of physics, unlike mathematical encryption. Mathematical encryption used today works on techniques of complex mathematical algorithms. Mathematical algorithms are vulnerable to being hacked by powerful computers. On the contrary, cracking quantum encryption would necessitate violating the laws of physics.

4.Potential attacks on cryptography:

The most acclaimed application of quantum computation is the attacks on cryptographic systems that are currently in use. The existing quantum computers don’t suffice the power to replace classical supercomputers. They have been proven theoretically to have massive potential which includes breaking blockchains’ cryptographic functions which are presently considered to be secure from the supercomputers. On the other hand, a quantum computer would crack these cryptographic shields in very little time. But, this threat is only conjectural as of today and is believed will be a reality in about a decade.

The last application sounds captivating, isn’t it? But before diving into this, we need to get acquainted with what cryptography and cryptocurrency are in specific.

What is Cryptography?

The word “cryptography” is a juncture of two words. The prefix “crypto” meaning hidden or concealed, the other being the suffix “graphy” meaning to write. Hence, the combination connotes “the method of securing information and communications” using codes so that only authorized parties can read and process it.

With the use of Quantum computing, the algorithms used to secure web pages, encrypted email, and many other types of data could be hacked easily. This will lead to significant ramifications and threats to electronic privacy and security.

For a better understanding of the upshot of Quantum computing on cryptography, we will take a look at a narrower fragment of cryptography that is currently a buzzword these days: cryptocurrency.

What is Cryptocurrency?

Cryptocurrency by literal meaning means “hidden currency” due to its non-existence in a physical form, unlike the typical paper currency. It is a digital capital that works as a medium of exchange.

For example, let us take Bitcoin.

Bitcoin Image

Currently, Bitcoin is one of the most trending topics which has gained immense popularity. It is the first decentralized cryptocurrency that was released as open-source software in 2009. Later, as an aftermath of Bitcoin, the other cryptocurrencies have evolved. Other cryptocurrencies include Ethereum, Ripple, Dash, Litecoin, Dogecoin, zCash.

In this asset, the individual holdings or coins are recorded, stored, and maintained in a publicly available distributed ledger called the blockchain. This blockchain is a computerized database that is protected using strong cryptography. This protection secures transaction records, controls the creation of additional coins, and validates the transfer of coin ownership.

How Quantum Computing can pose a threat to Cryptocurrency?

Google has announced that it has achieved quantum supremacy. Subsequently, many predictions have been rising, directing towards the demise of presently used cryptography in general, and Bitcoin in specific.

Presently, about 25% of the Bitcoins in circulation are vulnerable to a quantum attack.

Powerful quantum computers may ravage all the blockchains that rely on the ECDSA (Elliptic Curve Digital Signature Algorithm), including Bitcoin. ECDSA is used in creating keys under the public key cryptographic system. This is used to sign transactions in most blockchains. It allows us to create a random 256-bit private key and a deriving public key. The public key is created for sharing with any third party. As of today, it is unfeasible to find the private key that generated the public key. But quantum computers can employ an algorithm to untangle the mathematical relationship between a public key and a private key. Thus, the private key will be hacked.

To counteract this robbery, you should transfer your coins to a new p2pkh address. But even after doing this, still, your wallet might be impacted by others who don’t take such protection measures. In case if everyone does this, then too there is a possibility that quantum computers will advance to such an extent that they will outstrip this protection too. In this manner, the entire blockchain will be sabotaged. The Bitcoin blockchain will be fundamentally broken. This will lead to the robbery of a large number of Bitcoins and the price will most likely crash and people will lose confidence in this technology.

Conclusion:

The field of quantum computing in its present-day state is still in its infancy stage. The aforementioned threat is abstract as of today. Still, according to researchers working in this field, it is said that it will be a reality in about a decade. So, currently, the cryptocurrency blockchains are secured. We have no idea how fast a quantum computer will become in the future. If a quantum computer ever gets closer to the 10 minutes mark to derive a private key from its public key, then the Bitcoin blockchain will be broken. In such a case, shifting to post-quantum cryptography and quantum encryption is the best solution.

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Sanskruti Dube
GDSCVITBhopal

Content Writer at Google Developer Student Club VIT Bhopal | Pursuing B. Tech CSE in Artificial Intelligence and Machine Learning