The blockchain industry is not limited to the distributed ledger technology as many companies tend to use different innovations. Perhaps one of the most mysterious developments remains the quantum blockchain. The launch of the first network built on a quantum DLT was announced in spring 2017 by a team of the Russian Quantum Center. The concept of a “quantum threat” concerning the blockchain is also known in the community. It means that when building a quantum computer of a specific power, it can almost instantly decipher the algorithms of blockchain networks, such as that of Bitcoin.
DeCenter asked Yaroslav Lunev, the CEO of CellFrame—a project aimed at developing a blockchain protocol using “post-quantum” encryption—about how realistic this threat is and how the blockchain industry can benefit from the introduction of standards of quantum mechanics.
If not everyone understands what the blockchain is and how it works, then a quantum computer is completely unknown to the public. Let’s try to explain to the ordinary reader what it is and what benefits it provides.
I must say at once that I am absolutely not the person who should answer this question. I am not a physicist, but an amateur, so I will try to make it interesting and “not explain it the wrong way.”
An ordinary computer uses the concept of a bit in a binary system as an atomic particle of information that has only two possible values: one or zero. A quantum computer is based on “qubits,” which, being in superposition, can have more values and thus be more effective.
To make it more clear, we can bring one amateurish analogy, which is not an exact description but allows us to feel the difference between a classical computer and a quantum one. We have a phone book with a list of names and phone numbers, each name consists of ten letters, and each number is six digits. Thus, this database of 1 million values (lines) will require 15.26 megabytes (128 million bits) to save it on a regular computer, while on a quantum one, we need only 16 qubits.
Yes, it is technically incorrect to say “save”; it is better to say “conduct operations,” but this example is needed to understand the difference in orders. In short, it can increase the reachable amount of computation.
Imagine, for example, that we have a computer model of the human body, in which every cell or even every molecule behaves in the same way as in life. We could simulate a bunch of things: the behavior of molecules of new drugs with individual molecules of the body, nuclear reactions for the construction of a new generation of reactors, phase transitions in gaseous media, plasma physics, and so on.
Another example, closer to crypto enthusiasts is a quantum threat, that is, a quantum computer which can, for example, hack the Bitcoin blockchain. Traditional computers can very well multiply numbers, but they deal poorly with factorization. By “poorly,” I mean that this problem is solved by brute force, and this is not very effective. This is the basis of cryptography, we can still remember about PoW mining. Thus, for a very long time, a very powerful computer could theoretically crack the signature on the blockchain.
This, of course, depends on the power of the computer, but still is billions of trillions of years. Although I may be mistaken by several million, but this is not important. We must understand that such a hack today is impossible.
But a quantum computer with several thousand qubits can do this. Moreover, it does not need time for this, that is, it is not like “it will be able to do this a sextillion times faster,” it’s like 1 or 0, mean it’s either instantly accomplished or not.
In general, it is important to simply understand the approximate essence of the subject, and forecasts are ungrateful things.
Although scientists are actively working on implementing the concept of a quantum computer, researchers argue that quantum computers will gain mass distribution only in 10–15 years. Do you agree with this forecast?
My opinion here is worth nothing, I am not working on a quantum computer. 10−15 years? Maybe yes. Maybe no. It does not matter. Just when quantum supremacy becomes permanent, quantum stable encryption should already be the standard, and standards are not created in one year.
In January of this year, IBM introduced the first 20-qubit quantum computer. In your opinion, is this really an essential stage in the development of quantum computers, and is there enough power of this computer for practical use?
There is a nuance, it lies in the fact that this is the first commercial quantum computer with 20 qubits. That is, it is a stable 20-qubit system that can be sold and operated.
For the market, this is probably important. From the point of view of things that we talked about, it’s too early to be frightened of. Today, a similar system of 20 qubits can be emulated on a home computer, the only question is how much RAM we have.
In your opinion, what important events in the field of quantum computing should occur in the next two to three years?
Here it is better for me to remain silent. It is better to contact the Russian Quantum Center for comment.
Then let us turn to the concept of a quantum blockchain. How exactly can we combine these two technologies? And what for?
At this point, it is worth, finally, to tell about our project. Our protocol is post-quantum, not quantum. This means that it can be used after the quantum computer is created while a quantum blockchain would apply the principles of a quantum computer. Although it can be added that, due to the universality of the system, nothing prevents the future from adding a quantum key exchange to CellFrame and releasing the real quantum token in the same ecosystem.
In other words, we create the most efficient protocol using quantum-resistant encryption. Quantum-resistant signatures themselves are more used now, which imposes limitations in terms of efficiency. Therefore, we use the pure C language almost everywhere to be closer to the hardware and make a more efficient product than any of the created blockchains.
Another caveat is that we do not fully know which signatures or algorithms are actually quantum-stable. We can only calculate and assume everything.
Right now, there is a Post Quantum Cryptography project at the National Institute of Standards and Technology, where very smart people are trying to standardize algorithms and signatures, they are checking and filtering out various options in several rounds.
Therefore, we have laid down in the protocol the variability of encryption, that is, the ability to change the types of encryption on the go. We have implemented four different options so far, but we will wait for the results of this project and implement everything we need.
So is the quantum blockchain able to overcome the theoretical threat from the quantum computer itself?
This is the complexity: we can only reason in theory, there is no practice as yet.
What is the significance of the post-quantum blockchain, if it becomes popular, for the participants of the blockchain industry? What will change?
We tend to think that all our future will be post-quantum. At least “just in case.” Therefore, the future simply needs a similar protocol.
Will your protocol have a public or private blockchain network? What business model? Maybe you are planning to offer something to companies?
The network is public, but with the ability to create private “shards” and networks. From the point of view of monetization, we can equally effectively move both toward corporate customers and retail.
If we talk about specific solutions, we are about to launch a distributed VPN on our protocol. Our solution will eliminate the boundaries in the use of the Internet anywhere on the planet, regardless of the DPI or national firewalls. In addition, we use post-quantum encryption, and the protocol bandwidth limit is the bandwidth of the hardware itself.
Please tell us briefly about other key members of your project team.
The roots of our team are drawn from Akademgorodok Novosibirsk. I myself am from there. Dima Gerasimov, our technical director and author of the architecture, has been engaged in network security for the last ten years, has launched several commercial VPN systems. Zhenya Grishakov, our operating director, has extensive experience in building business systems.
We all have experience with the blockchain, each of us has participated in several projects. In addition, probably, Vasily Sumanov and Dmitry Chirkin do not need to be introduced, they are also members of the team. We also have several international advisors.
Who finances your project? What businesses may be interested in a promising development that will become relevant only after the start of the work of a real quantum computer? Or is the project being implemented under a non-commercial grant?
We have a private investor and own funds, the project is being implemented with these funds. It would be incorrect to say that the relevance of the development depends on the appearance of a quantum computer.
The prospect of our development is in its architecture, which maximally effectively utilizes the resources of a computer system and can be used at any level from mainframe to smart refrigerators.
When planning, we thought about a system that could handle the flow of hundreds of millions of users daily. I understand that a dozen projects have made such claims before us, but we can provide something that no one has yet shown in the form of a system in detail and the code.
In 2017, scientists from the Russian Quantum Center (RCC) stated that they “launched the world’s first quantum blockchain.” Is this statement true?
I tend to believe the RCC. I can’t even imagine a reason not to believe them.
Why did banks become the “test site” for the quantum blockchain, the fact that Alexey Fedorov, an employee of the RCC, pointed out in an interview? Are they most interested in ensuring maximum data security?
Probably. Absolute security of information, especially financially significant information, is invaluable.