Blockchain under attack

1.

Although driven by the influx of capital and talents, the blockchain instry ushered in rapid development, but as an emerging instry, the frequent warning of its security vulnerabilities caused people to worry about the risk of blockchain

Yu Kequn, director of the national information technology security research center, pointed out that the emergence of blockchain has brought people a lot of expectations for privacy exposure, data leakage, information tampering, network fraud and other issues. However, there are still many challenges in the security of blockchain

Li Bin, assistant director of China Information Security Evaluation Center, analyzed that the current blockchain is divided into three types: public chain, private chain and alliance chain. No matter which type, it faces security challenges in algorithm, protocol, use, time limit and system. What is particularly critical is that the current blockchain is still facing 51% attack problem, that is, nodes can successfully tamper and forge blockchain data by mastering more than 51% of the network examples

it is worth noting that in addition to external malicious attack risk, blockchain also faces the threat of its endogenous risk. Yu Kequn reminded that how to build a complete security application system around the equipment, data, application, encryption, authentication and authority of the application system of the whole blockchain is an important problem that all parties must face

Wu Jia also analyzed that as an emerging instry, employees in the blockchain instry are lack of safety awareness, which leads to the low safety factor of the software and hardware related to the blockchain and a large number of security loopholes. In addition, there are many ecological links in the whole blockchain. In contrast, the strength of the relevant security employees is scattered and it is difficult to form a joint force to solve the problem. A systematic solution is needed to meet the above challenges

content source: zhongxin.com

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4.

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5. 100m bandwidth has little to do with the connected computer
because the connected computers are controlled by the policy settings of the router
the most important thing is to allocate your bandwidth reasonably. In theory, if you download resources from a computer in your network segment, if your router does not allocate bandwidth, it may cause the computers in the whole network segment to get stuck on the Internet
if the distribution is reasonable and the router is powerful, then 200 computers can be easily handled.

6. In a simple explanation, 51% attack is also called majority attack. It means that malicious miners control more than 50% of the hash rate of the blockchain network, and then attack the network and take over the blockchain network, so that criminals can reverse transactions, stop payment or prevent new transactions from being confirmed
for more information about 51% attacks, you can learn about them on the password finance network,

7. Micro three cloud replied: blockchain developers can 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.

8. How to protect my bitcoin after bifurcation
if bitcoin really forks, as an ordinary user, the biggest risk is replay attack
what is replay attack? If bitcoin is split into one or more bitcoins, such as btc1 / btc2 / btc3, each bitcoin account will have a corresponding number of all bifurcated coins according to its bitcoin balance
because the address, private key, algorithm, etc. on each chain are the same, and the transaction format is also the same, the transaction initiated on one blockchain can be broadcast on another blockchain and may be confirmed. This is the "replay attack."
in short, when you transfer btc1, your btc2 / btc3 may also be transferred at the same time
however, at present, many forked coins have done two-way anti replay attack processing to avoid the risk of replay attack after forking.

9. Heteromorphic attack, also known as address pool pollution, refers to the intrusion and pollution of nodes between similar blockchain systems. This is an attack that most public chains are likely to face. The opportunity of this attack is that many public chains have handshake protocols with similar chains, and then the system can not identify whether the node belongs to its own chain. The attacker can use this point to collect the address of the public chain and make a malicious handshake, contaminate the address pool through the node handshake, so that the nodes of different chains shake hands with each other and push the known nodes in their respective address pools to each other, causing more nodes to contaminate each other and eventually spread to the whole network. The communication performance of the node under heteromorphic attack will decline, and the node will be blocked, which will eventually lead to the abnormality of the main network. The security of blockchain system is not only provided by technology itself, but also provided by developers. The more careful the program logic designed by developers, the lower the possibility of being broken. Therefore, if you need to develop a system, you must find a reliable development company. Xuanling technology is a reliable blockchain development company. Their strength and experience in blockchain development are trustworthy. If you have any intention, you can consult their company.

10. The result of these two attacks is that the other party's system is out of service or crashed e to information overload. But DoS attack is a single server attack, while DDoS attack is distributed multiple servers attack, the success of the attack is higher. The application of blockchain technology should be more and more, so it is necessary to understand the knowledge of blockchain. It is recommended that you go to the official website of Xuanling technology. This website has many popular science and application posts of blockchain technology, which should be of great help to blockchain learning.