Blockchain is a marvel of modern technologies. With DLTs and hashed records, businesses can truly benefit by adopting this technology.
If you've been closely analyzing the news cycle around blockchain, you'll realize that it's been positive, for the most part. But there have also been experts who have constantly come forward to warn the general public about technological advancements that could raise a number of concerns in blockchain or can even make it obsolete. One of the biggest sources of that concern is quantum computing.
Quantum computing refers to the kind of technology that can perform all sorts of calculations just on the basis of the probability of an object’s state before formal measuring is done.
This means that individuals will be able to use quantum computing for processing more data as compared to the amount of data that can be processed with the help of classical computers that are used currently. This is also where quantum computing generates fear.
There are individuals who believe that once quantum computing is developed, the security mechanism of blockchain will become crackable. This includes asymmetric cryptography and hashing.
If we look objectively at this picture, then these concerns are justified in some ways. But there is a lot more than that to the picture. In this article, we’ll be exploring just what that is.
Understanding Quantum Computing
Before understanding the impact of quantum computing, it is first important to know what quantum computing means. The most prominent advantage of using quantum computing is that it is able to process more data.
When it comes to quantum computing, then operations are carried out with the help of quantum states of an object that produces ‘qubit.’ These states also refer to various undefined properties of an object, like the spin of the electron or the polarization of a photon. This allows the qubits to hold two positions at the same time.
This entire phenomenon is known as superposition. This is the secret weapon of quantum computing.
The phenomenon of superposition reduces the total number of operations that a computer has to perform before solving a problem. Because of this, the task of
using quantum computing for solving various complex queries at the same time becomes very easy. Quantum computers are also different from classical computers as they do not use a base 2 numerical system.
This means that bits are not used to exclusively communicate and process data. All of these features together have led many experts and scientists to conclude that quantum computing can potentially crack the cryptographic protocol with ease.
Many organizations in the blockchain industry have taken this seriously, and they have launched various plans and strategies for adapting the blockchain ecosystem according to the standards of quantum computing. One such plan of action is
Ethereum for quantum computing. According to Justin Drake, who is an Ethereum researcher, Ethereum 3.0 will consist of a plan that addresses the potential threat that quantum computing can pose for the blockchain technology. It was further suggested that other organizations should also come up with their own Ethereum for quantum computing plans.
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What is Asymmetric Cryptography, Symmetric Cryptography, and Hashing?
Now that we know what quantum computing means, the next step on the journey of understanding the effect of quantum computing on blockchain-based products is to understand the concepts related to blockchain that can be targeted. Some of the essential concepts are explained in brief below.
- Asymmetric Cryptography
Asymmetric cryptography is commonly known as public-key cryptography. This type of cryptography makes use of two different kinds of keys, including a public key and a private key, to carry out every single transaction.
The task of the public key is to encrypt a message while the private key is responsible for decrypting a message. It is important for both of the keys to be used together for carrying out any particular transaction.
- Symmetric Cryptography
Symmetric cryptography refers to the type of cryptography within which the same cryptographic key is used for both encryption and decryption. This can be compared to how every individual uses the same key to both lock and unlock a door to his or her home.
Hashing refers to the process of scrambling data into a unique set of numbers or letters. This unique set of numbers or letters represents specific data. This means that if there is any other piece of untampered data, then it would produce the exact same hash.
According to the press release, which Ethereum released with respect to quantum computing, the two primary security tools of blockchain are hashing algorithms and encryption via asymmetric cryptography.
How Does All of This add up?
Let’s understand how all of this adds up. Asymmetric cryptographic algorithms secure blockchains as they are based on prime numbers and factors. In every single blockchain protocol, both public keys and private keys consist of extremely large numbers that have been hashed into a smaller quantity of letters or numbers. Since it’s almost impossible for classical computers to find the prime factors of gigantic numbers; this makes blockchain extremely secure and tamper-proof.
However, it is possible for individuals to use quantum computing for optimizing combinations and probabilities. This means that a quantum computer would possess the ability to perform combinatorial calculations of bigger numbers at a very deep level in comparison to classical computers. This point to the fact that not only will quantum computers be able to solve complex numbers but quantum computers will also have the capacity to do all of that quickly. Hence, a quantum computer would be able to use superposition to easily crack any asymmetric cryptography that serves the purpose of securing the blockchain.
The next question that you might have is, what about hashing? Is it possible to use quantum computing for posing a security threat to hashing algorithms? Thankfully, the answer to these questions is no. Blockchain is secured by both encryptions via asymmetric cryptography and hashing. A key difference that exists between encryption and hashing is that hashing cannot be reversed. So, the threat that quantum computing can pose for hashing is significantly smaller than what it does for encryption. This has led many experts to believe that Ethereum 3.0 might be using a similar strategy for quantum computing safeguarding.
The Defense of Bitcoin against Quantum Computing
No conversation about blockchain is complete without talking about Bitcoin. This is mainly due to the fact that Bitcoin revolutionized the digital economy and brought a lot of positive attention towards blockchain.
To further shower praise on the Bitcoin protocol, it has been revealed that the protocol for Bitcoin was built with quantum computers in mind. Hence, it does have some built-in resistance against quantum computers. This also means that steps taken by
Ethereum for quantum computing safeguarding were not the first initiatives.
According to experts, the SHA-256 hashing algorithm is used in Bitcoin. This hashing algorithm is partly safe against any attacks from quantum computers. Further, the fact that Bitcoin addresses are only used once and are revealed only when the user sends the Bitcoin means that any quantum computer would have a very narrow window to find the private key.
This is not particularly easy to accomplish. It is also very encouraging to note that apart from Bitcoin and Ethereum, there are other blockchain-based organizations that are even taking the idea of this disruption very seriously. This has led to many organizations formulating plans of action that they would follow to protect their platform and cryptocurrency against any possible attacks from quantum computers.
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The Future Quantum Threat
In this article, we have discussed various potential
uses of quantum computing. But one thing that we haven’t done till now is talk about the fact that in the current age, quantum computers exist in a very rudimentary form.
This has led many experts to even come out and say that it’s not worth it for organizations to protect against threats from quantum computers at this stage, as it would take a minimum of 10-15 years for quantum computers to develop capabilities to "hack" a blockchain.
There are other experts who even question whether building a quantum computer would be possible or not.
This goes to show that while the threat that quantum computers possess for blockchain is just possible thinking scenarios at this point in time. However, this does not mean that organizations should not take quantum computing seriously. If real quantum computers are ever developed in the future, then they can pose a serious challenge to the blockchain.
Hence, instead of placing a bet on what happens and what does not. It is important for organizations to prepare against such considerations at this point in time instead of trying to catch up later when serious damage has already been done.