Position: Home page » Blockchain » Quantum computing or breaking the two gates of blockchain

Quantum computing or breaking the two gates of blockchain

Publish: 2021-05-14 12:26:31
1. Introction: quantum blockchain technology is a professional Internet technology service provider integrating computer software and hardware research and development, digital currency proction and asset management. Its main business is to mine the most core value digital currency in the world, especially bitcoin. It belongs to quantum blockchain Technology (Guangzhou) Co., Ltd
legal representative: Xu Rong
time of establishment: April 28, 2018
registered capital: RMB 10 million
enterprise type: limited liability company (invested or controlled by natural person)
address: 205, building 3, No. 6, Jiapin third Street, Shatou street, Panyu District, Guangzhou City
2. Blockchain itself solves the problem of large-scale cooperation between strangers, that is, strangers can cooperate with each other without mutual trust. So how to ensure the trust between strangers to achieve mutual consensus mechanism? The centralized system uses trusted third-party endorsements, such as banks. In the eyes of the common people, banks are reliable and trustworthy institutions. The common people can trust banks to solve real disputes. But how does a decentralized blockchain guarantee trust
in fact, blockchain uses the basic principles of modern cryptography to ensure its security mechanism. The knowledge system involved in the field of cryptography and security is very complicated. Here, I only introce the basic knowledge of cryptography related to blockchain, including hash algorithm, encryption algorithm, information digest and digital signature, zero knowledge proof, quantum cryptography, etc. Through this lesson, you can learn how to ensure the confidentiality, integrity, authentication and non repudiation of the blockchain using cryptography technology
basic course lesson 7 basic knowledge of blockchain security
1. Hash algorithm (hash algorithm)
hash function (hash), also known as hash function. Hash function: hash (original information) = summary information. Hash function can map any length of binary plaintext string to a shorter (generally fixed length) binary string (hash value)
a good hash algorithm has the following four characteristics:
1. One to one correspondence: the same plaintext input and hash algorithm can always get the same summary information output
2. Input sensitivity: even if the plaintext input changes slightly, the newly generated summary information will change greatly, which is greatly different from the original output
3. Easy to verify: plaintext input and hash algorithm are public, anyone can calculate by themselves, and whether the output hash value is correct
4. Irreversibility: if there is only the output hash value, the hash algorithm can never dece the plaintext
5. Conflict avoidance: it is difficult to find two plaintexts with different contents, but their hash values are the same (collision)
for example:
hash (Zhang San lent Li Si 100000 yuan for 6 months) = 123456789012
such a record as 123456789012 is recorded in the account book
it can be seen that hash function has four functions:
simplify information
it is easy to understand, and the information after hashing becomes shorter
identification information
you can use 123456789012 to identify the original information, and summary information is also called the ID of the original information
hidden information
the account book is a record like 123456789012, and the original information is hidden
verification information
if Li Si cheated that Zhang San only lent Li Si 50000 when repaying, both parties can verify the original information with the hash value of 123456789012 recorded before
hash (Zhang San lent Li Si 50000 for 6 months) = 987654321098
987654321098 is completely different from 123456789012, which proves that Li Si lied, Then the information can't be tampered
common hash algorithms include MD4, MD5 and Sha series algorithms, and Sha series algorithms are basically used in mainstream fields. Sha (secure hash algorithm) is not an algorithm, but a group of hash algorithms. At first, it was SHA-1 series, and now the mainstream applications are sha-224, SHA-256, sha-384 and sha-512 algorithms (commonly known as SHA-2). Recently, Sha-3 related algorithms have been proposed, such as keccak-256 used by Ethereum
MD5 is a very classic hash algorithm, but unfortunately, both it and SHA-1 algorithm have been cracked. It is considered by the instry that its security is not enough to be used in business scenarios. Generally, sha2-256 or more secure algorithm is recommended
hash algorithm is widely used in blockchain. For example, in blocks, the latter block will contain the hash value of the previous block, and the content of the later block + the hash value of the previous block will jointly calculate the hash value of the later block, which ensures the continuity and non tamperability of the chain< Encryption and decryption algorithm is the core technology of cryptography, which can be divided into two basic types: symmetric encryption algorithm and asymmetric encryption algorithm. According to whether the key used in the encryption and decryption process is the same or not, the two modes are suitable for different needs, just forming a complementary relationship, and sometimes can be combined to form a hybrid encryption mechanism
symmetric cryptography (also known as common key cryptography) has the advantages of high computational efficiency and high encryption strength; Its disadvantage is that it needs to share the key in advance, which is easy to leak and lose the key. The common algorithms are des, 3DES, AES and so on
asymmetric cryptography (also known as public key cryptography) is different from the encryption and decryption key, and its advantage is that it does not need to share the key in advance; Its disadvantage is that it has low computational efficiency and can only encrypt short content. Common algorithms include RSA, SM2, ElGamal and elliptic curve series. Symmetric encryption algorithm is suitable for the encryption and decryption process of a large number of data; It can't be used in signature scenario: and it often needs to distribute the key in advance. Asymmetric encryption algorithm is generally suitable for signature scenario or key agreement, but it is not suitable for large amount of data encryption and decryption< Third, information digest and digital signature
as the name suggests, information digest is to hash the information content to obtain a unique digest value to replace the original and complete information content. Information digest is the most important use of hash algorithm. Using the anti-collision feature of hash function, information digest can solve the problem that the content has not been tampered
digital signature is similar to signing on paper contract to confirm contract content and prove identity. Digital signature is based on asymmetric encryption, which can be used to prove the integrity of a digital content and confirm the source (or non repudiation)
we have two requirements for digital signature to make it consistent with our expectation for handwritten signature. First, only you can make your own signature, but anyone who sees it can verify its validity; Second, we want the signature to be only related to a specific file and not support other files. These can be achieved by our asymmetric encryption algorithm above
in practice, we usually sign the hash value of information instead of the information itself, which is determined by the efficiency of asymmetric encryption algorithm. Corresponding to the blockchain, it is to sign the hash pointer. In this way, the front is the whole structure, not just the hash pointer itself< Zero knowledge proof means that the verifier can make the verifier believe that a certain conclusion is correct without providing any additional information to the verifier
zero knowledge proof generally meets three conditions:
1. Completeness: authentic proof can make the verifier successfully verify
2. Soundness: false proof can not make the verifier pass the verification
3. Zero knowledge: if you get proof, you can't get any information other than the proof information from the proof process< With more and more attention paid to the research of quantum computing and quantum communication, quantum cryptography will have a huge impact on the information security of cryptography in the future
the core principle of quantum computing is that qubits can be in multiple coherent superposition states at the same time. Theoretically, a large amount of information can be expressed by a small number of qubits and processed at the same time, which greatly improves the computing speed
in this way, a large number of current encryption algorithms are theoretically unreliable and can be cracked, so the encryption algorithm has to be upgraded, otherwise it will be broken by quantum computing
as we all know, quantum computing is still in the theoretical stage, which is far from large-scale commercial use. However, the new generation of encryption algorithms should consider the possibility of this situation.
3. At present, there are four main types of consensus mechanisms: pow, POS, dpos, pool
1. POW workload proof, which is familiar with mining, calculates a random number that meets the rules through and or operation, that is, obtains the bookkeeping right, sends out the data that needs to be recorded in this round, and stores it together with other nodes in the whole network after verification
advantages: complete decentralization, free access of nodes
disadvantages: bitcoin has attracted most of the computing power in the world, and other blockchain applications using POW consensus mechanism are difficult to obtain the same computing power to ensure their own security; Mining causes a lot of waste of resources; The period of reaching consensus is long, which is not suitable for commercial application.

2. Proof of rights and interests of POS, a mechanism of upgrading consensus of pow; According to the token proportion and time of each node; It can rece the difficulty of mining in equal proportion, so as to speed up the speed of finding random numbers< Advantages: to a certain extent, it shortens the time to reach a consensus
disadvantages: mining is still needed, which does not solve the pain point of commercial application in essence

3. Dpos share authorization certification mechanism is similar to the voting of the board of directors, in which the coin holders cast a certain number of nodes to verify and account on their behalf
advantages: greatly rece the number of participating verification and accounting nodes, which can achieve second level consensus verification
disadvantages: the whole consensus mechanism still depends on token, and many commercial applications do not need token to exist

4. Pool verification pool, which is based on traditional distributed consistency technology and data verification mechanism; It is a consensus mechanism widely used in the instry chain at present.
advantages: it can work without token, and realizes second level consensus verification on the basis of mature distributed consistency algorithms (pasox and raft)
disadvantages: the degree of decentralization is not as good as that of bictin; The multi center business model is more suitable for multi-party participation

it has great advantages in using consensus mechanism to ensure data consistency (the consensus mechanism is first proposed by ripple, and the network transaction synchronization mechanism with data correctness priority. In the consensus network, no matter how the software code changes, if you can't reach a consensus, you can't enter the network, let alone fork)
- - - - - - - -
PS: a little black, although the consensus mechanism can absolutely ensure that there will be no hard bifurcation at any time. However, the disadvantage of this mechanism is obvious, that is, it is much longer than the current bitcoin network to reach a consensus with other nodes. In extreme cases, the consequences of disconnection in ripple consensus mechanism network are also very terrible

it is possible that one day after the power failure in your home, the whole system will no longer be able to reach a consensus with other rippled nodes (in fact, the consensus mechanism requires more than 80% of the nodes to acknowledge your data before your submission will be accepted by other nodes, otherwise it will be rejected by exclusive nodes), Even you can only empty all your 500 GB data and resynchronize to connect to other ripple nodes

so at present, the existing rippled end is not suitable for civil use (if it is commercial, the impact is relatively small. For example, RL's own rippled node is hosted in Amazon cloud data center. If it has no response for a long time, it can make high claims, and there is almost no break in that place except for large disasters). This is one of the aspects RL has always wanted to improve.
4. Some, such as Tencent security led the blockchain, based on the cryptographic algorithm that can resist the attack of quantum computing environment, created the overall strong security blockchain solution of trusted data.
5.

5g is 5g

blockchain is the third power of blockchain

it's not clear. Do you want to ask if the three logics of quantum computing

are different, and there is a little sense of mutual promotion

5g solves the problem of wireless transmission speed, which is many times faster than 4G

blockchain was formerly PPP protocol, It is the point-to-point transmission protocol

used to solve the congestion problem of the central node. Quantum computing to improve the download speed is a breakthrough of Moore's law, which can solve the limit problem of computing speed in the limited space

for more information, please refer to this article, what is blockchain, can you explain it easily

6. It can only be said that before the advent of quantum computing, blockchain is safe, mainly because no one has seen how much computing power quantum computing brings

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.
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. < UL >
  • in the current situation, quantum computers can't help with bitcoin mining.
  • turning to quantum computers will not affect the mining speed, because with the soaring price, the difficulty of mining will increase.
  • indeed, The introction of quantum algorithm will put the traditional cryptocurrency system at risk
  • < / UL >

    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 addresses

    in 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 bitcoin

    9.

    on the evening of October 23, Beijing time, the 150th anniversary edition of Nature magazine published a paper claiming that Google has successfully achieved "quantum hegemony" this event named "Hello world" in the quantum field immediately occupied the front page of the mainstream media, and the description of "quantum computing in 200 seconds = 10000 years of the most powerful supercomputer on earth" in the paper has become a hot topic of the whole Internet

    at present, many cryptography and quantum cryptography experts are advocating the establishment of financial security system as soon as possible, except that the encryption currency projects such as TaiFang and quantum chain focus on quantum resistance. According to William tooton, a reporter from Bloomberg technology, on twitter last month, the National Security Bureau has been committed to the research of related technologies. Therefore, unless the threat of quantum computing suddenly erupts, bitcoin still has time to deal with its arrival“ Bitcoin is alive, consensus is there, currency is there, if not upgraded, it will not disappear because of algorithms or vulnerabilities. But the problem of quantum resistance has not been solved. With the continuous development of quantum computers and the arrival of more qubit chips, this will still be the sword of Damocles hanging on the head of cryptocurrency. "< br />

    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?
    Hot content
    Inn digger Publish: 2021-05-29 20:04:36 Views: 341
    Purchase of virtual currency in trust contract dispute Publish: 2021-05-29 20:04:33 Views: 942
    Blockchain trust machine Publish: 2021-05-29 20:04:26 Views: 720
    Brief introduction of ant mine Publish: 2021-05-29 20:04:25 Views: 848
    Will digital currency open in November Publish: 2021-05-29 19:56:16 Views: 861
    Global digital currency asset exchange Publish: 2021-05-29 19:54:29 Views: 603
    Mining chip machine S11 Publish: 2021-05-29 19:54:26 Views: 945
    Ethereum algorithm Sha3 Publish: 2021-05-29 19:52:40 Views: 643
    Talking about blockchain is not reliable Publish: 2021-05-29 19:52:26 Views: 754
    Mining machine node query Publish: 2021-05-29 19:36:37 Views: 750