Blockchain cannot be falsified
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 keyAs of May 2020, blockchain and digital currency are illegal in China
according to the announcement of the people's Bank of China Central Network Information Office, Ministry of instry and information technology, State Administration for Instry and commerce, China Banking Regulatory Commission, China Securities Regulatory Commission and China Insurance Regulatory Commission on preventing the risks of token issuance and financing, Article 2 no organization or indivial shall illegally engage in token issuance and financing activities. Organizations and indivials that have completed the token issuance and financing should make arrangements such as refund, reasonably protect the rights and interests of investors, and properly handle risks. Relevant departments will seriously investigate and deal with the activities of token issuance and financing that refuse to stop and the illegal behaviors in completed token issuance and financing projects
Article 3 strengthen the management of token financing trading platform
from the date of this announcement, any so-called token financing trading platform shall not engage in the exchange business between legal currency and token and "virtual currency", and shall not buy or sell token or "virtual currency" as a central counter party, and shall not provide pricing for token or "virtual currency" Information intermediary and other services
extension data
"illegal financial institutions and illegal financial business activities ban" stipulates that:
eleventh, the criminal suspect, funds and property involved in illegal financial institutions and illegal financial activities, and the public security organs shall take compulsory measures according to law to prevent suspect from escaping and transferring funds and property. p>
Article 12 the people's Bank of China shall, after investigation and confirmation, make a decision to ban the illegal financial institutions and financial business activities, declare them illegal, order them to stop all business activities, and make an announcement
Article 13 if the people's Bank of China discovers that a financial institution opens an account, handles settlement and provides loans for an illegal financial institution or illegal financial business activities, it shall order the financial institution to stop the relevant business activities immediately. No unit or indivial may use the relevant funds without authorizationhowever, it's easy for people with an eye to see why there is no security layer? In fact, several key features of blockchain have already solved the security problem. First, the blockchain uses asymmetric encryption technology. In fact, encryption and decryption are different keys, namely public key and private key. In short, the public key is open to the public, while the private key is absolutely confidential
secondly, distributed bookkeeping is a way for blockchain to store data. It can also be understood as distributed storage, which is consistent with the concept of decentralization. In the form of ledger, there is no central ledger in the network, and the ledger is stored in each node. Each node is not only independent, but also can act as the central node. Therefore, the central node will not be attacked, leading to the loss of core books or data, and the whole network will not be paralyzed
moreover, tamper proof is the basic feature of blockchain. As long as the chain can not be modified, and can not be deleted. If it needs to be changed, based on the principle of transparency and openness, the whole network and all nodes need to be informed. Therefore, under the democratic mechanism, the possibility of tampering with data at will is very low. Therefore, blockchain technology is applied in various instries, such as finance, payment, traceability, games, etc., such as the network "universe", Tencent's "come together to catch the demon", and Zhongan Huanyu blockchain "Dr dragon hunt" are the safe and high-quality procts under the blockchain technology.
Chinese Mahjong: the world's earliest blockchain project
first of all, a initiates an application. I want to play mahjong and set up a mahjong Bureau, which is equivalent to creating a block, and this block will be broadcast to B, C, D, a, B, C, C, C, C, C, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D D...
in the process of playing mahjong, the above four people constantly play cards, which can be understood as mining, through what to mine? Mahjong machine can understand the mineralization machine. These four miners are the so-called miners. These four miners collide from 144 mahjong, and any right card can be Hu card. We can understand the 144 mahjong as a series of hash values (numbers). The process of Hu card is called computational power. Until Hu card, it means that the right hash value is collided and you can get a reward, Each person will pay the corresponding chips to C and put them in the blockchain. The reward is bitcoin or other virtual coins
Why do the other three people take the initiative to reward C? That's because these people have automatically reached a consensus that C has indeed won, and everyone has recorded the account, including the family members who are sitting next to buy horses. It's not good to deny it, otherwise when it comes out that the character is not good, no one will play with him again. After all, the circle is very important
when we reached a consensus, we didn't see any intermediary or third party judging that C had won, and the rewards given to C didn't need to be transferred to C through the third party. All of them were direct point-to-point transactions. This process was decentralization. The card players (miners) recorded their own achievements in the first game, and the third team won the first game, After the record is completed, a complete block is generated. But remember, this is only the first round. In the whole blockchain, this is just a node. The first eight rounds are finished, that is, eight nodes (blocks). Eight blocks are connected together to form a complete account book, which is the blockchain. Because everyone has one account book, it is a distributed account book. The purpose is to prevent someone from tampering with records. In the end, it is clear who wins or loses.
as a trademark, the "blockchain" lacks significance, which directly indicates the characteristics of the instry, so it can not be registered successfully. However, words with significant meaning can be added in front of the "blockchain", so that it can be registered as a trademark
for trademark registration issues, please refer to our Ruima trademark registration
I'm afraid that many people have seen such news and some companies are doing such projects by using the transparency of blockchain to solve the problems of the music instry. But have you ever thought about using blockchain to make music? Is it really necessary for the audience
the emergence of streaming media has spoiled the audience. Although musicians are against this mode, almost all technology giants have deployed streaming media. The emergence of this mode makes it difficult for the traditional physical record mode to turn over. Big brands such as Taylor swift and Adele refuse to cooperate with streaming media platform in order to promote record sales, But in the eyes of streaming media managers like music tank, this refusal is only temporary. In the final analysis, musicians feel that they have made less money and are aggrieved. The key point is that the audience pays less. Do users care about the income of the musicians
here we emphasize a problem. Blockchain can only solve the problem of falsification, but it can't solve the problem of piracy. It's very easy to pirate music and other digital procts
of course, it's not that there is no possibility of success. I just say that there will be a lot of resistance to this kind of application, and users will not like it. Only musicians will have the motivation to promote it. On the other hand, for trading users, blockchain can provide transparency, and it can also bring efficiency and cost advantages to the exchange, so its resistance is relatively small
blockchain will have a profound impact on finance, logistics, crowdfunding (European crowdfunding), certification and securities.