Will Google's realization of "quantum supremacy" threaten digital currency?

1. Google develops a quantum computer

Recently, according to foreign media reports, Google researchers published an article on NASA's official website earlier this week, which showed that Google's quantum computer completed a calculation in 3 minutes and 20 seconds, while the world It would have taken the first supercomputer, Summit, 10,000 years to do the same calculation.

According to the Google researchers, this means that quantum computers have achieved "quantum supremacy", that is, they can perform calculations that were not possible before.

"Compared with all known classical algorithms, this astonishing computational speed experimentally confirms the advantages of quantum computing and heralds the long-awaited computing paradigm," the authors wrote.

Google researchers also stated that "the system can only perform a single, highly technical calculation, and it will be years before quantum computers can be used to solve practical problems".

2. Scientists' exploration of quantum computers

In fact, quantum computers are not the first to be developed by Google. Earlier, the established technology giant IBM and the start-up company Rigetti Computing have developed quantum computer prototypes, but their prototypes can only complete the same tasks that traditional computers can complete at a faster speed, and their advantages over traditional computers are not obvious. .

This time, Google's quantum computer surpassed the traditional computer in a certain calculation with an absolute advantage, marking a major breakthrough in the field of quantum computing for Google, so it has attracted great attention from the global scientific and technological community, especially in the field of digital currency. of high attention.

3. Advantages of quantum computers over traditional computers

We know that the basis for the operation of existing digital currencies is cryptography, based on public and private keys for asymmetric encryption.

The fundamental reason why this system is safe is that with the current supercomputers, it takes longer than the life of the universe (13.8 billion years) to deduce the corresponding private key from the public key. Therefore It is an impossible task.

If the quantum computer can be put into practical application, the decryption of the private key will be easily solved. Take Google's quantum computer as an example. According to published data, its calculation speed is 1.752 billion times that of a traditional computer.

If it can also be used to crack the private key, the approximate time required is no longer 13.8 billion years but only 8 years.

The iteration speed of quantum computers is exponential, which is much faster than that of traditional computers, so cracking in seconds will be just around the corner.

4. Quantum computers will not threaten digital currencies

So is the building of digital currency really going to be crumbling?

No, mainly for the following reasons:

1) Current quantum computers lack effective algorithms

Deciphering a private key not only requires computing power, but actually requires a suitable algorithm to operate.

This is like our high-speed train with a speed of 300 kilometers per hour, but to go from Guangzhou to Beijing, there needs to be railway tracks between the two places. If the track route of the high-speed rail twists and turns through a bunch of other provinces, while the track of the ordinary train is a straight line from Guangzhou to Beijing, then under such circumstances, the high-speed rail will take many detours, and it may take longer than the ordinary train It will be longer.

The high-speed rail train here is like a quantum computer, and the high-speed rail line is like an algorithm.

Because the architecture of quantum computers is very different from that of traditional computers, their algorithms also need to be redesigned.

At present, quantum computers still lack an algorithm to effectively crack the private key, so although the computing power has increased by 1.752 billion times, it still takes a long time to find a hash collision.

2）There are already many digital currencies in the layout against quantum computers

Many of the existing digital currencies already claim to have the ability to resist quantum computer attacks, such as NEO. In addition, Ethereum has also incorporated anti-quantum computers into its development plan in its planned 2.0 path.

We believe that more large-scale public chains will start to deploy in this area.

3）It will take a long time before quantum computers are actually put into use

As the Google researchers themselves put it, "it will be years before quantum computers can be used to solve practical problems." The machines currently made by Google are just prototypes, and a lot of engineering optimization is still needed before the prototypes can be used in practice.

During this time, the tech community is sure to find more ways to combat quantum computing, too.

So this news is a major positive for the technology community, but it is not necessarily a negative for digital currencies, so we don't need to worry too much.