Quantum computing blockchain
in fact, in the real world, even if quantum computing is implemented, if the topology of the whole network is still in accordance with the existing model (the infrastructure will be updated for many years), quantum computers can only greatly improve the computing power on a few nodes and obtain accounting rights, So basically, quantum computing should be safe before it reaches everyone's personal computer.
Zhongke Shuguang (603019) [trading tips]: the E-Class supercomputer prototype system development project has been launched
Inspur information (000977) [trading tips]: Inspur electronic information company, a subsidiary, participated in the development of "Shenwei Blu ray" supercomputer
variety show (600770) [trading tips]: engaged in the proction of supercomputer related chips
other concerns: Great Wall of China (000066), Huasheng Tiancheng (600410) and Tiantong (600330)
the influence of quantum computer on the mining of special currency
at present, we do not have such quantum algorithm, but what should we do if we find it in the future? As we all know, bitcoin aims to identify the speed of mining, and also increases the difficulty of mining. It means that the difficulty of finding the algorithm will become more complex
in fact, it is impossible to mine with ordinary computers, so miners use ASIC chips to dig bitcoin. At present, there are two kinds of cryptocurrency, RSA and elliptic curve cryptocurrency. In fact, these two cryptocurrency methods are vulnerable to quantum computer attacks. According to Anastasia, we only need 2500 cubits to interrupt algoant, interrupt EC, and about 4000 cubits to interrupt RSA
Hackers can identify bitcoin wallet addressesin the current situation, hard forking is impossible because many users have lost their wallet addresses and coins. Now, the worry is that quantum computers can easily help track lost wallets, and hackers can use them to decrypt and retrieve such lost coins
However, the main focus is the research of quantum computer. The entry of such computer system will make the cryptocurrency system face risks. The system could be the destroyer of bitcoinon May 3, 2017, a big news in science and technology circles: the world's first optical quantum computer surpassing the early classical computer was born. This "world's first" is a genuine "made in China" and is the result of a breakthrough made by Professor Pan Jianwei and his colleagues of the University of science and technology of China and Professor Wang Haohua of Zhejiang University
if the speed of traditional computer is bicycle, the speed of quantum computer is just like airplane. In the past few months, IBM and Intel have announced that they have built 50 and 49 qubit quantum computers, respectively. Some experts point out that within ten years, the computing power of quantum computer may catch up with and surpass the current supercomputer
at the American Physics Annual Meeting held in Los Angeles on March 5, 2018, Julian Kelly, a research scientist at Google quantum AI laboratory, reported that he was leading the Google team to test a 72 qubit universal quantum computer. However, this is only 72 qubits. At this rate of development, the magic power of quantum computer will soon be terrifying
then, why do we say that quantum computers can easily crack bitcoin? What's the matter
it takes 600000 years to crack an RSA cryptosystem, but it takes less than three hours to use a quantum computer with considerable storage function! In other words, with the leap from electronic computer to quantum computer, the computing power and the ability to process big data of the whole mankind will be improved for tens of thousands or even hundreds of millions of times. In front of the quantum computer, the traditional electronic computer we used to be proud of is equivalent to the previous abacus, which is bulky and old
although the bitcoin protocol uses asymmetric cryptocurrency, the corresponding public key is used to verify the transactions signed by the private key to ensure that bitcoin can only be used by legitimate owners. It is not feasible to force the private key to be consistent with the public key by using the currently available computer, but quantum computer can solve the problem of asymmetric cryptocurrency
in addition, the rule of bitcoin is that the more processed block will be added to the blockchain, and the other block will be voided. For example, it's like 51 people in an account book say that you have saved 100 yuan in the bank, while 49 people say that you have saved 50 yuan. In this case, the minority of blockchain algorithm is subordinate to the majority, and the bank thinks that you have saved 100 yuan is true, and that you have saved 50 yuan is false. So once a miner has 51% of the computing power, other subsequent miners will not be able to continue to get bitcoin
Andersen Cheng, co-founder of a network security company in the UK, says bitcoin will come to an end the day quantum computers come into use. What's your opinion?
in short,
quantum computer is to replace the original ordinary bits with quantum bits
from the physical level, quantum computers are not based on ordinary transistors, but use spin direction controlled particles (such as proton nuclear magnetic resonance) or polarization direction controlled photons (mostly used in school experiments) as carriers. Of course, in theory, any multi-level system can be used as the carrier of qubits
from the perspective of calculation principle, the input state of quantum computer can be either discrete eigenstate (like traditional computer) or superposition state (probability superposition of several different states). The operation of information is extended from traditional logic operations such as "and", "or", "and" to any unitary transformation, and the output can also be superposition state or an eigenstate. So quantum computer will be more flexible and can realize parallel computing< If you want to explain the details, it's a bit troublesome. I'll give you some key words to look up:
1. Quantum state
2. Quantum superposition
3, qubit
4, unitary transformation
5, quantum logic
6, quantum gate (corresponding to traditional logic gate, In fact, it is some special positive transformation)
7, quantum algorithm, quantum algorithm (of course, quantum computer can also realize the traditional algorithm)
8, and then on how to realize from the physical level, it is best to start with quantum optics, because polarized photons are the simplest
in depth:
ordinary digital computers run on binary systems of 0 and 1, which are called "bits". But quantum computers are far more powerful. They can operate on qubits and can compute values between 0 and 1. Suppose an atom placed in a magnetic field rotates like a top, so its axis of rotation can point up or down. Common sense tells us that the rotation of atoms can be up or down, but not all at the same time. But in the strange world of quantum, the atom is described as the sum of two states, an upward turning atom and a downward turning atom. In the wonderful world of quantum, every object is described by the sum of all the incredible states
imagine a string of atoms arranged in a magnetic field and rotating in the same way. If a laser beam is shining on the top of the atoms, it will jump down the group of atoms and quickly flip the rotation axis of some atoms. By measuring the difference between the incoming and outgoing laser beams, we have completed a complex quantum "calculation", involving a lot of rapid spin movement
from the perspective of mathematical abstraction, quantum computer performs the calculation with set as the basic operation unit, while ordinary computer performs the calculation with element as the basic operation unit (if there is only one element in the set, quantum calculation is no different from classical calculation)
take the function y = f (x), X ∈ a as an example. The input parameter of quantum computation is the domain a, and the output domain B is obtained in one step, that is, B = f (a); The input parameter of classical calculation is x, and the output value y is obtained. The range B can only be obtained by multiple calculations, that is, y = f (x), X ∈ a, y ∈ B
quantum computer has a problem to be solved, that is, the output range B can only randomly take out a valid value y. Although the number of elements in output set B is much less than that in input set a by directing the unwanted output to an empty set, it still needs to be calculated many times when all the valid values need to be taken out.
behind, a woman ran after her, holding a hundred yuan note in her left hand and a kitchen knife in her right hand, screaming in Mandarin: "return my virginity! Return my virginity! ", A look of heartbreak
(at that time, I thought, did the man play a hooligan and not pay enough to be chased?)
seeing a woman chasing after her with a knife, the man had to stop and say to the woman, "OK, OK, I'll pay you back."
(I can't understand it any more. Do you want to rob people of their virginity and money? Oh, my God! It's heartless! I want to cut him off.)
the woman gave the man a hundred yuan note, and the man gave the woman dozens of yuan
(the more you look at it, the more confused you become. How can you earn money by taking someone's virginity? Look at the man's appearance. If he can be the second male, the old sow can climb trees.)
the end of the song is the end of the song
(when I woke up today, I suddenly realized that the man had paid the counterfeit money and was chased by the shopkeeper: "give me back the real money!")
Zhongshan Library is on Wenming Road, but now it is renovated and temporarily moved to the first floor of the comprehensive building of guihuagang campus of Guangzhou University. It is far away from Tianhe