Can quantum computing overcome the blockchain? Researcher: Encryption technology should be transformed into anti-quantum direction

From the current state of computing technology, the main selling point of the blockchain and its applications is that encrypted distributed ledgers are actually "unbreakable" under normal circumstances. However, its effectiveness depends to a large extent on the premise of “technical status”. If a paradigm shift occurs in the computing world, contemporary blockchain-based systems can be vulnerable to design flaws. But how urgent is the threat that can happen at any time?


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The advances that physicists have made in building operational quantum computers over the past three decades have quickly contributed to this shift. As quantum computers perform better on specific tasks than traditional computers, the milestone of quantum supremacy can be realized at any time. The question of whether quantum-based devices can "chall" blockchains in the future has become a concern. Focus.

Introduction to Quantum Computing Knowledge

A quantum computer is any device that uses the principles of quantum mechanics to perform calculations. In order to store and manipulate information, a conventional computer uses a binary unit called a bit, also known as a bit, which can only represent one of two possible states 0 or 1. Quantum machines rely on qubits (also known as qubits), which can be both 0 and 1. This phenomenon is called superposition, which makes these devices perform certain tasks much faster than "bit-based" devices.


(Quantum digit maps of data and organization implemented. Source: MIT Qubit Counter)

Another basic term for quantum theory is entanglement. When two particles are entangled, they exist in the same quantum state. If the state of one of the particles changes, no matter how far the two particles are in physical space, the state of its peers will A corresponding change has occurred. Qubits paired in this way can exponentially increase the computational power of quantum computers.

The superimposed state is a state necessary for calculation, and it is difficult to achieve and difficult to maintain. Physicists use lasers and microwave beams to position quantum in this state of operation, and then use a range of techniques to protect them from the slightest temperature fluctuations, noise, and electromagnetic waves. Due to the fragility of the work environment, current quantum computers are very error-prone, and the fragility of the working environment dissipates in a process called quantum decoherence before most operations are performed.

Quantum computing power depends on how many qubits a machine can utilize at the same time. Starting with the two qubits obtained in the first experiment in the late 1990s, the most powerful quantum computers operated by Google today can use up to 72 qubits.

Quantum computer and blockchain

The blockchain acknowledges all traditional doubts, and its invariance and unparalleled security are widely accepted. The blockchain laid the foundation for public trust in digital assets and promoted large-scale adoption. However, the advent of quantum computing can jeopardize the integrity of public key cryptography as a pillar of security for blockchains.

Although quantum computers have a wide range of potential applications, one of the most relevant applications in the context of blockchain technology and cryptography is that their ability to run specific algorithms is much faster than any existing supercomputer. One of the most widely discussed hypothetical use cases is to run the well-known Shor's algorithm, which may take a few streets out of many contemporary encryption techniques.

A group of researchers at the Russian Quantum Center pointed out in an article in the journal Nature that a potential risk stems from blockchain security that relies heavily on one-way mathematical functions (ie, The fact that a function that runs but is more difficult to reverse compute). These features are used to generate digital signatures and verify transactions on the ledger.

Criminals equipped with functional quantum devices will be able to reverse computing faster, which will enable them to forge signatures, impersonate other users and gain access to their digital assets. When mining, such a malicious participant can take over the process of updating the ledger, thereby manipulating the transaction history and performing a double currency.

Russian researchers suggest that designers of encryption systems should immediately begin to take precautions against this threat. One solution might be to replace traditional digital signatures with anti-quantum cryptography, a security algorithm designed to withstand attacks from quantum computers that are powerful enough. Another remedy proposed by Russian physicists can only be implemented when there is a quantum Internet, and it has been going on for decades. This future wireless communication architecture, based on the connection between remotely entangled quantum particles, will open up a large number of new blockchain models and designs.

This is somewhat consistent with the puzzling views expressed in a recent research paper by Del Rajan and Matt Visser of Victoria University of New Zealand. They proposed to abandon the use of quantum cryptography and directly transform the blockchain into a quantum-based system. Their model describes a qubit-based blockchain that is not only spatially entangled but also entangled in time. If the particles are not completely destroyed, it is impossible to retroactively change the transaction records encoded by the state history of the individual particles. However, this model was not possible until the quantum Internet was established and operational.

Practitioners have their own opinions

While future solutions proposed by academia may take decades, much of the actual research and development in quantum computing and quantum cryptography is in full swing. Experts in the field of quantum computing applications involved in the Cointelegraph survey have different views on the urgency of quantum threats. Yaniv Altshuler, MIT's researcher and CEO and co-founder of the predictive analytics platform Endor Protocol, said:

"Quantum computers are becoming extremely powerful, and they are growing faster than most people expect. However, their ability does not break the blockchain. Every year, when new hardware is released, it will re-ignite people's blockchain. Concerns about integrity, but there is no evidence that quantum computing can damage blockchains."

Stewart Allen, chief operating officer of the quantum computing company IonQ, believes that when the number of equivalent sub-computers is developed enough to threaten the integrity of today's blockchain, the security system will move to algorithms that can contain them. He said:

"In the short term, quantum computers do not constitute a real threat to block blockchain cryptography. If this happens, cryptography will shift to more quantum-proof algorithms. To solve quantum computer cracking Blockchain encryption will take at least a decade."

However, others do not fully agree with this optimistic view.

Norbert Goffa, ILCoin's executive manager, expressed concern about possible quantum-based mines:

"If someone has a quantum-based mine, then it's easy to control others. Today, we don't have any quantum-based mining machines. On the other hand, many companies have been working on quantum-based computing. We believe that This will become a reality in the next five years. Maybe the time will be shorter, who knows?"

Rakesh Ramachandran, CEO and co-founder of QBRICS Inc., emphasized that quantum computing will have an impact on almost every area of ​​cryptography. He said that in terms of blockchain technology, we may expect a systematic shift:

"Quantum computers will not only redefine blockchain cryptography, but will also redefine anything that applies cryptography, including online banking sites. Developers are currently doing a lot of research and work to mitigate this impact, And to the transformation of anti-quantum cryptography or post-quantum cryptography.

However, the challenge of blockchain is not only the threat represented by quantum computing, but also how the blockchain will transform into new cryptography. The estimated time for all experts to pose a threat to the integrity of blockchains by quantum computers is strikingly similar, ranging from 5 to 10 years. In dealing with potential quantum attacks, their methods are quite consistent: most people believe that it is necessary to gradually turn to anti-quantum cryptography and build an infrastructure to support this technology. Blockchains must evolve, but quantum computing technology is unlikely to fundamentally threaten their existence.