Quantum Computing Vs. Blockchain
Crypto assets may not be afraid of a quantum computer.
The cryptocurrency community has long been discussing one technical feature of the blockchain, which directly affects its future. We are talking about the threat to the blockchain from the so-called quantum computing. The fact is that if these threats are implemented, crypto assets will not be able to function technically and all problems with their regulation will disappear by themselves.
Indeed, what is the point of creating a serious regulatory system for an instrument that will soon become simply inoperable?
Most modern cryptocurrencies are built on a particular cryptographic algorithm that ensures its security. The level of protection is determined by the amount of work required by the key, the password that determines the final result of the cryptographic conversion. It is known that when solving cryptography problems, the classical computer performs total testing of possible keys, in turn, one after another. A quantum computer can instantly test a set of keys and establish a combination that has the maximum probability of being true and thereby compromise the cryptosystem.
The threat to bitcoin is that high-speed quantum computers, as a result, will be able to “create problems” to the encryption processes and digital signatures used in the technology of blockchain and virtual currencies. Ultra-fast calculations would in principle allow to forge smart contracts and steal “coins”.
Most cryptocurrencies use public key encryption algorithms for communications and, in particular, digital signatures. Public key cryptography is based on one-way mathematical functions-operations that are simple in one direction and difficult in the other. If we use quantum computers rather than classical ones to solve the factorization problem, it is solved much faster. Quantum computer allows for a couple of minutes to determine the secret key on the public, and the knowledge of the secret key allows you to access the address of the bitcoin network. It turns out that the owner of the quantum computer will be able to break the encryption system with a public key and write off (steal) “coins” from the appropriate address. This feature of quantum computing is the main danger for bitcoin.
According to some estimates, the quantum computer will be able to determine the secret key on the open in 2027.
Some commentators believe that with the advent of full-fledged quantum computers, the era of cryptocurrencies and blockchain will come to its logical end — the cryptography systems on which cryptocurrencies are based will be compromised, and the cryptocurrencies themselves will become worthless. Allegedly, the first thing that the owner of a quantum computer will do is quickly mine the remaining bitcoins, ethers and other popular crypto-coins. Experts have estimated that bitcoin hacking will require a quantum computer with a capacity of 10 thousand qubits, and it is not so long to wait for it — perhaps ten years, or even less.
However, not everyone shares this opinion.
According to new forecasts, a commercially acceptable version of the quantum computer will not appear until 2040.
Many cryptocurrency experts are sure that by this moment developers will be able to prepare and adapt the blockchain to new realities. They will be able to modify the cryptocurrency code and protect the technologies used in it from hacking.
Analysts, however, emphasize that although an attacker with a powerful quantum computer will be able to get the secret key from the public, it is impossible to get the public key from the bitcoin address of the recipient of the transaction. The public key is converted to a bitcoin address by several unidirectional hash functions that are resistant to quantum computation. However, in fact, the public key still gets into the network one day. This occurs when the transaction is signed by the sender of the “coin”. Otherwise, the network will not be able to confirm the transaction, because there is no other way to verify the authenticity of the sender’s signature.
The widespread fear of a direct threat to bitcoin by quantum computing is exaggerated and comes from ignorance. In fact, using crowdsourcing, blockchain technology solves many problems, including reducing threats to its security from quantum computers. That is why the network based on the blockchain for superior protection network and platform of centralized architecture. Dr. Brennan has analyzed the threat of blockchain technologies by modern systems of quantum computing. He investigated the potential of a quantum computer in terms of the possibility of its use “for manipulating the blockchain in the centralization of hashing power” and assessed the probability of disclosure of the key of the encryption system that underlies the mechanism of protecting users of the blockchain. The results of the study show that the existing developments in the field of quantum computing are very far from the “imaginary possibilities” of quantum technologies — the modern quantum infrastructure is characterized by speed, absolutely insufficient to solve extremely complex problems such as the search for an acceptable time encryption key.
At least on the horizon of the next 10 years, the speed of quantum computers will be insufficient compared to the capabilities of modern mining machines.
Bitcoin will not give way before quantum computing.
Can Quantum Computing Take Over Blockchain?
Practice crosses out any theoretical constructions that claim that quantum computing is able to “master” the blockchain. This is due to the limited capabilities of existing technical means and the ongoing development of the blockchain protection system. The technology that can compromise the work of the blockchain is becoming obsolete by the time of its appearance, it is constantly about ten years behind the development of blockchain technology.
The head of the laboratory of quantum computing John Martinis from Google also rejected the assumption that quantum computing could pose a direct threat to blockchain systems and cryptocurrencies in the near future. Martinis believes that the process of creating quantum computers will take at least a decade, and the practical implementation of effective quantum computing will require even more time. He believes that the creation of quantum devices “is really problematic and much more difficult than the creation of a classical computer”.
From another angle, one of the world’s leading experts in the field of bitcoin and blockchain Andreas Antonopoulos also looked at the problem under consideration.
Andreas Antonopoulos official Twitter page:
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He is convinced that the US NSA and other intelligence agencies will not use a quantum computer against bitcoin, even if they have such weapons.
Andreas Antonopoulos said:
“I’m not at all worried that the NSA might have a quantum computer, because the basic security law says: if you have a powerful secret weapon, you do not use it. You need a very significant excuse to use it”.
He cited as an example the decryption by the British cryptographer Alan Turing of the German military machine encryption Telegraph messages “Enigma” during the Second World War. The Germans used this machine, in particular, for secret communication in the Navy. The British government then decided to keep this success in the strictest confidence, and by any means to hide the source of information (it was removed from the communication channels). The British had even deliberately not to prevent the sinking of their ships by the Germans, because as soon as the enemy realizes the compromise of the codes used by him, he immediately takes measures to Refine its technology.
The question of the threat of quantum computing is not the existence of a quantum computer, but its power — the number of quantum bits (qubits). Special services at this stage of development can not have enough power to attack the Bitcoin blockchain. However, a really real problem will arise when quantum computers become commercially available, but not so much that everyone can use them in their bitcoin wallet. During this transition period, bitcoin will need to switch to new algorithms. It is not yet clear how this transition will take place.
Researchers estimate the exploitability of the ideas of quantum-secured blockchain, the essence of which is that the Central element in the protection technology of the blockchain to make the quantum technology of quantum communication. Quantum communications (or, more precisely, quantum key distribution) guarantee security based on the laws of physics, not on the complexity of solving mathematical problems, as in the case of public key cryptography. As a result, the quantum blockchain (it can be defined as a set of methods of using quantum technologies for calculations; the work of the quantum blockchain is based on the use of quantum communications to authenticate the participants of operations) will be invulnerable to attacks using a quantum computer.
Brennen and Tucker agree that quantum computing, at least on paper, definitely poses a threat to the security of blockchain networks. Feed her fears caused by the injection of panic sensational articles in the media. Tucker believes that the talk that quantum computing poses an immediate threat to the blockchain is distracting from the really important topics for discussion. The quantum threat to bitcoin cannot be completely excluded, but the level of this threat is estimated as minimal, especially if we take into account the high reliability of the network of this cryptocurrency and powerful incentives to ensure the highest level of its security.
Perhaps, from all this, it is possible to draw two conclusions. First, bitcoin in the current modification is really vulnerable to quantum computing. Secondly, it is equally obvious that there are and there will be many opportunities in the future to improve it. On the one hand, it is, in particular, alternative systems of cryptographic protection of transactions, and including on the basis of public key ciphers, on the other — quantum communication systems that guarantee the security of communication without the use of mathematics.
So quantum systems promise new means of protection of virtual currency blockchains. If we turn to ordinary money, it can be noted that as technological development is constantly evolving and their means of protection. Remember how to protect against counterfeiting of conventional paper money is constantly coming up with new and unusual technologies. From all this, it follows that from a technical point of view, crypto assets are for a long time, which makes their regulation useful.