How does blockchain face quantum computer

1. The relationship between blockchain and big data is not very big. The main purpose of big data is to manage massive data, and the core of blockchain is to achieve high security and high reliability of data without centralized intermediary accounting. Therefore, blockchain and big data do not conflict with or replace each other. They are completely different solutions for data in different scenarios.

2. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
blockchain is an important concept of bitcoin, which is essentially a decentralized database and the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block
let's talk about the social or economic significance of blockchain. In fact, many of the previous technologies were devoted to "proctivity". For example, artificial intelligence is a kind of progress in proctivity. The blockchain, which has greatly improved the proction relations, is committed to the proction relations. So why do you say that
because the so-called proction relationship is actually how to do business between people and business partners. And these things, originally, are in the cognitive process between people, and there is no special program to program or quantify it
for example, if you and I are good friends now, we can do business. If someone stirs up our relationship and we are not good friends, we will not do business. Even if we can make money in business, we will not do business because there is no trust between us
as for blockchain, it is actually because the data is authenticated by all nodes and backed up at the same time, so my data is as real as possible and can't be tampered with. In this case, if you believe my data, you can make a program on this basis, and then use the data to make what kind of business contract, what kind of service, what kind of service, and what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, etc This "proction relationship" of commercial cooperation is programmed. In this way, we believe in the data and the program compiled by the algorithm. Because you believe in the data and the program, you can develop all kinds of apps in the program. These apps are the proction relations and what business to do. This is: blockchain is actually a reconstruction of "proction relationship".

3.

One of the characteristics of blockchain projects (especially public chains) is open source. Through open source code, to improve the credibility of the project, so that more people can participate. But the open source code also makes it easier for attackers to attack blockchain system. In the past two years, there have been a number of hacker attacks. Recently, the anonymous currency verge (xvg) was attacked again. The attacker locked a vulnerability in the xvg code, which allowed malicious miners to add false timestamps on the block, and then quickly dig out new blocks. In a few hours, the attacker obtained nearly $1.75 million worth of digital currency. Although the subsequent attack was successfully stopped, no one can guarantee whether the attacker will attack again in the future

of course, blockchain developers can also take some measures

one is to use professional code audit services,

the other is to understand the security coding specifications and take preventive measures

the security of cryptographic algorithm

with the development of quantum computer, it will bring a major security threat to the current cryptosystem. Blockchain mainly relies on elliptic curve public key encryption algorithm to generate digital signature for secure transactions. Currently, the most commonly used ECDSA, RSA, DSA, etc. can not withstand quantum attacks in theory, and there will be greater risks. More and more researchers begin to pay attention to cryptographic algorithms that can resist quantum attacks

of course, in addition to changing the algorithm, there is another way to improve the security:

refer to bitcoin's treatment of public key address to rece the potential risk of public key disclosure. As users, especially bitcoin users, the balance after each transaction is stored in a new address to ensure that the public key of the address where bitcoin funds are stored is not leaked

security of consensus mechanism

the current consensus mechanisms include proof of work (POW), proof of stake (POS), delegated proof of stake (dpos), practical Byzantine fault tolerance (pbft), etc

POW faces 51% attack. Because POW depends on computing power, when the attacker has the advantage of computing power, the probability of finding a new block will be greater than that of other nodes. At this time, the attacker has the ability to cancel the existing transaction. It should be noted that even in this case, the attacker can only modify his own transaction, but not the transaction of other users (the attacker does not have the private key of other users)

in POS, attackers can attack successfully only when they hold more than 51% token, which is more difficult than 51% computing power in pow

in pbft, when the malicious nodes are less than 1 / 3 of the total nodes, the system is secure. Generally speaking, any consensus mechanism has its own conditions. As an attacker, we also need to consider that once the attack is successful, the value of the system will return to zero. At this time, the attacker does not get any other valuable return except destruction

for the designers of blockchain projects, they should understand the advantages and disadvantages of each consensus mechanism, so as to select an appropriate consensus mechanism or design a new consensus mechanism according to the needs of the scene

security of smart contract

smart contract has the advantages of low operation cost and low risk of human intervention, but if there are problems in the design of smart contract, it may bring greater losses. In June 2016, the Dao, the most popular funding project of Ethereum, was attacked. The hacker obtained more than 3.5 million Ethereum coins, which later led to the bifurcation of Ethereum into Eth and etc

there are two aspects of the proposed measures:

one is to audit the security of smart contract, and the other is to follow the principle of smart contract security development

the security development principles of smart contract are: to be prepared for possible errors, to ensure that the code can correctly handle the bugs and vulnerabilities; Release smart contracts carefully, do well in function test and security test, and fully consider the boundary; Keep smart contracts simple; Pay attention to the threat intelligence of blockchain and check and update in time; Be clear about the characteristics of blockchain, such as calling external contracts carefully

security of digital wallet

there are three main security risks in digital wallet: first, design defects. At the end of 2014, a user lost hundreds of digital assets e to a serious random number problem (repeated r value). Second, the digital wallet contains malicious code. Third, the loss of assets caused by the loss or damage of computers and mobile phones

there are four main countermeasures:

one is to ensure the randomness of the private key

The second is to check the hash value before installing the software to ensure that the digital wallet software has not been tampered with

The third is to use cold wallet

The fourth is to back up the private key

4. The highlights of the global economy range from manufacturing to real estate to Internet to finance, and then from the development of Internet Finance generation by generation to blockchain. I think this may be the last stop. It's like taking a train to the end. There won't be a stop in less than ten years. In 2018, all the suoha blockchain companies want to turn over and make some achievements, I believe this is the only opportunity for you to talk about your dreams again and seize the last opportunity in your life.

5. One of the characteristics of blockchain projects (especially public chains) is open source. Through open source code, to improve the credibility of the project, so that more people can participate. But the open source code also makes it easier for attackers to attack blockchain system. In the past two years, there have been a number of hacker attacks. Recently, the anonymous currency verge (xvg) was attacked again. The attacker locked a vulnerability in the xvg code, which allowed malicious miners to add false timestamps on the block, and then quickly dig out new blocks. In a few hours, the attacker obtained nearly $1.75 million worth of digital currency. Although the subsequent attack was successfully stopped, no one can guarantee whether the attacker will attack again in the future
of course, blockchain developers can also take some measures
one is to use professional code audit services,
the other is to understand the security coding specifications and take preventive measures
the security of cryptographic algorithm
with the development of quantum computer, it will bring great security threat to the current cryptosystem. Blockchain mainly relies on elliptic curve public key encryption algorithm to generate digital signature for secure transactions. Currently, the most commonly used ECDSA, RSA, DSA, etc. can not withstand quantum attacks in theory, and there will be greater risks. More and more researchers begin to pay attention to cryptographic algorithms that can resist quantum attacks
of course, in addition to changing the algorithm, there is another way to improve the security:
refer to bitcoin's treatment of public key address to rece the potential risk of public key disclosure. As users, especially bitcoin users, the balance after each transaction is stored in a new address to ensure that the public key of the address where bitcoin funds are stored is not leaked
security of consensus mechanism
the current consensus mechanisms include proof of work (POW), proof of stake (POS), delegated proof of stake (dpos), practical Byzantine fault tolerance (pbft), etc
POW faces 51% attack. Because POW depends on computing power, when the attacker has the advantage of computing power, the probability of finding a new block will be greater than that of other nodes. At this time, the attacker has the ability to cancel the existing transaction. It should be noted that even in this case, the attacker can only modify his own transaction, but not the transaction of other users (the attacker does not have the private key of other users)
in POS, attackers can only attack successfully when they hold more than 51% of the token, which is more difficult than 51% of the computing power in pow
in pbft, when the malicious nodes are less than 1 / 3 of the total nodes, the system is secure. Generally speaking, any consensus mechanism has its own conditions. As an attacker, we also need to consider that once the attack is successful, the value of the system will return to zero. At this time, the attacker does not get any other valuable return except destruction
for the designers of blockchain projects, they should understand the advantages and disadvantages of each consensus mechanism, so as to select an appropriate consensus mechanism or design a new consensus mechanism according to the needs of the scene
security of smart contract
smart contract has the advantages of low operation cost and low risk of human intervention, but if there are problems in the design of smart contract, it may bring great losses. In June 2016, the Dao, the most popular funding project of Ethereum, was attacked. The hacker obtained more than 3.5 million Ethereum coins, which later led to the bifurcation of Ethereum into Eth and etc
there are two aspects of the proposed measures:
one is to audit the security of smart contracts, and the other is to follow the principles of smart contract security development
the security development principles of smart contract are: be prepared for possible errors to ensure that the code can correctly handle the bugs and vulnerabilities; Release smart contracts carefully, do well in function test and security test, and fully consider the boundary; Keep smart contracts simple; Pay attention to the threat intelligence of blockchain and check and update in time; Be clear about the characteristics of blockchain, such as calling external contracts carefully
security of digital wallet
there are three main security risks in digital wallet: first, design defects. At the end of 2014, a user lost hundreds of digital assets e to a serious random number problem (repeated r value). Second, the digital wallet contains malicious code. Third, the loss of assets caused by the loss or damage of computers and mobile phones
there are four main countermeasures:
one is to ensure the randomness of the private key
the second is to verify the hash value before software installation to ensure that the digital wallet software has not been tampered with
the third is to use cold wallets
the fourth is to back up the private key.

6.

1. Most people don't know what a blockchain is

compared with traditional stocks, real estate, bonds, gold, etc., blockchain assets are a very abstract and virtual form of assets. Blockchain assets represented by bitcoin are a very specialized computer language and program running mode, There is no credit endorsement from any country behind it, nor does any enterprise give it securitization income, which completely depends on the mutual consensus trust between strangers. In this case, although the operation logic of decentralization has been completed, its experiment is only in the initial stage and development stage, and participating in relevant investment is actually a kind of brave adventurer behavior

2. The price of blockchain assets fluctuates violently

because there is not much support from the use level of entities, many blockchain projects are completely dependent on community operation and market speculation, so it is difficult for investors to hold blockchain assets from the perspective of value investment, which leads to frequent capital flow, and the situation of price fluctuations has become a normal. A blockchain related token can soar by 500% in a day, or fall by 90% in a few hours. This kind of drastic price fluctuation is not affordable to ordinary investors

3. The uncertainty of national policies is too great

as an underlying technology, blockchain has basically accepted its value all over the world. However, as the "companion proct" of blockchain, there are still great disputes on national policies, and with the continuous increase of digital currency trading volume, the impact on the global financial market is also increasing. At present, the daily trading volume of the whole digital currency field exceeds US $60 billion, which is comparable to the trading volume of China's Shanghai and Shenzhen stock exchanges, or the average daily trading volume of the New York Stock Exchange. It is impossible to continue to operate outside the supervision. There is a very large regulatory game cycle, and the policies of various countries in this regard may be introced one after another, The impact on the market cannot be ignored

4. All kinds of blockchain projects are good and bad

blockchain technology is originally a very basic architecture technology. At present, e to the global pursuit of funds, many project parties who have nothing to do with blockchain begin to use the concept of blockchain to design procts, And can complete the writing of the white paper of blockchain in a very short time, and then raise market funds. In this case, the technical threshold of the whole blockchain has been lowered. Many companies without the strength and willingness of blockchain development have developed the concept of blockchain purely to obtain financial support, resulting in the flooding of projects. The gap between projects is widening, but ordinary investors are difficult to identify and easy to fall into the trap

5. Currency speculation is not equal to blockchain investment

at present, there are many views that blockchain and digital currency are a whole. You can't develop blockchain technology while suppressing digital currency. I agree with this logic, but currency speculation is not the same as blockchain investment in the real sense. The thing with real investment value must be the thing with scarce supply. If any digital currency is issued, it can represent the application value of the blockchain and bring some innovation to the society. Then any blockchain technology team that can issue digital currency can issue dozens of digital currencies and change its name in a very short time. Therefore, digital currency itself has little logical relationship with blockchain assets. Blockchain projects must be a market with obvious scarcity, but digital currency does not have great scarcity. This is like saying that any Internet company can develop a chat software similar to wechat, but the chat software itself does not have much value. The real value lies in how many people participate in the chat software. Digital money is just a chat software. The current situation is that everyone is frying the software, and few people are concerned about what is on the software. p>

6. Short term overheating, easy to be used by lawless elements

the particularity of the blockchain instry is that many of the ecology has become very financial, in the whole process of operation, capital will be very concentrated, and most of the links are related to capital. From raising funds by ICO to sending tokens to investors, to online trading of exchanges, and trading of tokens by users in exchanges, the whole process is almost full of financialization. If the practitioners are not professional enough, have no self-discipline ability, and lack of supervision, then every link may be used by criminals to manipulate the market, Obtain all kinds of illegal income

In order to catch up with the next round of financial technology and digital revolution, Japan holds a very open attitude towards bitcoin and other transactions. Digital currency transactions denominated in Japanese yen occupy half of the whole legal currency trading area in the world, Japan hopes to use digital currency to revive its financial competitiveness. The United States hopes to use mainstream financial markets, such as futures and options derivatives market, to tame bitcoin and make it another powerful tool for us dollar hegemony. And China is also trying to promote sovereign cryptocurrency, one of the important purposes is to promote the internationalization of RMB. The field of digital currency and blockchain assets is likely to become the next big country's game and contention point, which will virtually increase the systematic risk to investors. It's hard to know what unexpected policies appear behind this big country's game and what impact they will bring to the whole market

8. The threat of quantum computer

blockchain generates a set of self-motivated system to ensure that it can run on its own under decentralized conditions. Most of them use asymmetric encryption, and use the corresponding public key to verify the transactions signed by the private key, so as to ensure that bitcoin and other blockchain assets can only be used by legitimate owners. But quantum computer can solve the problem of asymmetric encryption. Quantum computer can calculate the private key from the public key in a few minutes. After knowing all the private keys, people with quantum computer can spend bitcoin and other digital currency at will. Of course, when the quantum computer will come out is also a problem. The digital currency protocol is constantly adding new encryption standards, but the potential threat brought by the quantum computer has to attract the attention of investors

9. There is a possibility of a big reversal in the supply and demand level

the market value of the blockchain token market has hovered around us $trillion. Although OTC funds are still pouring in, the stability and growth rate of the capital inflow are questionable. The supply of encrypted digital currency is a very embarrassing thing. From the perspective of a single digital currency, the total amount is strictly limited. For example, there are only 21 million bitcoins, but the threshold of issuing encrypted digital currency is getting lower and lower. Anyone and any organization can issue encrypted digital currency anytime and anywhere, and the supply is almost unlimited. On the other hand, the increasing transaction cost is restraining the demand side. At present, investors in the transaction link need to pay the transaction fees in the exchange, and also pay the miners' fees when transferring money. If countries begin to tax digital currency transactions in the future, it means that this market will have to bear more operating costs without generating its own profitability, If coupled with the increasing supply level, the overall market supply and demand expectations may reverse in a moment

10. Lack of legal protection for blockchain assets

it is not uncommon that global digital currency exchanges have been "hacked", and in the process of all kinds of over-the-counter and on-the-spot transactions, fraud also occurs from time to time, and the legal protection for investors is very limited. Especially for domestic investors, once they are stolen or cheated because of trading digital currency, it is almost difficult to recover effectively. Due to the lack of intermediary guarantee from banks and other levels, the security of digital currency is entirely under their own responsibility. Although this is in line with the logic of self preservation of private property, it also brings greater uncertainty to the storage and transaction of digital currency assets. Before there is no complete legal system to protect the rights and interests of personal digital currency assets, the legal security of investment in blockchain related assets is a very serious problem

7. Jungle law infinite superposition flying bug steps: first enter the game after parachuting, first find a safe place, and then open the top left gear set key. After the setting key is turned on, this interface will appear. Click the reset key to enter the reset key page. It will prompt [when the terrain is stuck, please click the reset button], click Reset, and then the next time you click the gear, it will automatically return to reset. Then, click open the gear, click Reset all the time, click open the gear, and then click Reset... Repeat all the time. Next, friends will find a surprising event, that is, as you keep clicking the reset button, your height keeps rising, and then you fly up.

8. There are patches
this problem is actually very simple
your graphics card is OK! But the vertical synchronization of the graphics card is not off, so the FPS is very low. You can turn off the vertical synchronization in the properties of the graphics card
it must be this problem
the properties of the graphics card can be found by right clicking on the desktop, and then properties - Settings - Advanced<

vertical synchronization is off
in the 3D settings of the graphics card

9. We need to look at the mining income according to the model of the graphics card, and then use the income to look back at the cost time. If it is a low-end graphics card, it may not be able to be found in my life

10. Abstract: in a small laboratory in a secluded village 50 miles north of New York City, intricate pipelines and electronic equipment are wound under the ceiling. This seemingly haphazard pile of devices is a computer. It is different from any computer in the world, but it is a milestone device in the history --- quantum computer

on 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?