This month, Google made a big announcement. It was the unveiling of a new quantum computer chip called Willow. Willow is a superconducting quantum chip that operates at temperatures below -200 degrees Celsius and has 105 qubits. Considering that IBM's previously announced quantum chip was 1,000 qubits, 105 qubits may not seem like a high performance, but according to the paper, the Willow chip surprised the academic world by suggesting the possibility of drastically reducing the occurrence of 'errors', which were previously considered a chronic problem of quantum computers. However, this innovative quantum chip unexpectedly had negative effects in an unexpected field. That is, cryptocurrency prices plummeted. The price of Bitcoin, which had been fluctuating around $100,000 since the election of President Trump, fell below $95,000 with the announcement of Willow, and altcoins fell even further. Of course, there is a good chance that other factors, such as the US Federal Reserve’s tightening policy preference, could have an impact, but since concerns have long been raised that quantum computers will threaten blockchain-based cryptocurrencies, the view that Willow’s influence is also dominant. So, let’s examine whether the concern that quantum computers could lower the value of cryptocurrencies is based on evidence. First, there is a claim that if quantum computers are introduced, cryptocurrency mining will become easier and the value of cryptocurrencies will fall. To sum up, this does not seem to be a big concern. When people try to explain quantum computers in an easy way, they often say that quantum computers can solve problems that would take a long time to solve with conventional computers in an instant, but this is only true for certain calculations. In fact, academics believe that quantum computers will not be very fast in the calculations that mine cryptocurrencies, that is, in solving hash functions. Specifically, there is analysis that it will be about twice as fast in Bitcoin mining. Of course, if the mining volume is unlimited like Dogecoin, the coin supply in the market will increase when the mining speed increases, which may lower the coin price, but most cryptocurrencies, such as Bitcoin and Ethereum, have a set maximum supply and can adjust the mining speed. The possibility of a value crash due to oversupply is low. So what is the cryptocurrency industry really worried about? It's because of 'hacking'. To conclude, this hacking concern is very real. Arthur Herman of the Hudson Institute in the US said that if someone develops quantum computer hacking capabilities and tries to use them to attack cryptocurrencies, it's only a matter of time. Google predicts that it will happen in 10 years at the earliest, and there are mixed market forecasts that it will happen sooner or later, but the risk is clear. As I mentioned earlier, quantum computers are not good at solving all problems, but rather specific problems. They have already proven to be excellent at solving prime factorization and discrete logarithm problems that can break most current security measures. Furthermore, there is a good chance that they can break blockchains. Let's hear it directly from an expert. [Bang Jeong-ho / Professor at Yonsei University's Convergence Science and Technology Institute: (If you ask a computer) to multiply a number, it calculates it. But if you give it a number and ask it what it is made of, it takes a very long time. But in the 90s, a paper was published saying that quantum computers can do that very quickly. Such an algorithm was developed. However, most of the modern encryption used recently is RSA, which is based on factoring. So, when quantum computers are developed, it became a scenario that encryption systems based on factoring would be able to be decrypted quickly.] Fortunately, a technology that can respond to this is being developed. It is the 'quantum-resistant encryption' technology that constructs encryption using problems that quantum computers cannot solve. It is easy to construct encryption, but it is difficult to solve it in reverse, not only for general computers but also for quantum computers, such as lattice-based problems. Of course, if another algorithm is developed, it is not guaranteed that this problem will be safe, but several technologies are being discussed as promising. Then, if quantum-resistant encryption is applied before hacking becomes a reality, why is the cryptocurrency industry so worried about the emergence of quantum computers? The reason is, ironically, because of decentralization, which is considered the greatest strength of cryptocurrencies. The existing financial system is managed by a central institution such as a central bank, so it is easy to switch to a new security system if necessary, even if it costs money. Cryptocurrencies are decentralized, meaning there is no central institution. In order to introduce new security t