Blockchain risk

1.

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

2. There must be risks, and they are high risks, because high returns are always bound with high risks. You are a little rookie who doesn't know anything. Can you make money like other people's old birds? If you are just interested in the coin circle, I suggest you don't be reluctant to spend a small amount of money to add a pay circle of the coin circle. For example, the group of Li Xiaolai, the big money in the coin circle, once cost as much as 5 million yuan. There are also some old cats and baoerye groups, but they are too far away from us ordinary people. But if you have a lot of money, it's a good deal. If it's only tens of thousands, it's suggested to add some groups with high cost performance, such as the payment group of fire chain blockchain, Zhongshen blockchain club, which are reliable, and there is a free trial period.

3. Forget the private key, the mnemonic note lost... This is the most basic. When it comes to the essence of investment, it is the investment risk caused by the fluctuation of currency price. GRE global risk trading all specialized insurance can be bought to avoid the risk of digital money market.

4. How much risk you can take and how much you will get in return. Just like in troubled times, people who rise up may fall to the ground or become the next emperor. The question is, do you dare@ Block chain God Tucao: make complaints about investment risks correctly.

5. Yes, blockchain is a high-risk project.

6. You mean digital currency? Digital currency based on blockchain technology has good performance in operation security, but it also exposes many problems. Most governments are cautious or resistant to the current non legal digital currency, and the research on legal digital currency continues to improve. The main risk is that there is no commercial application foundation and it can't be realized. Honghua coin has done a good job in this aspect. He has cooperated with Chinese people all over the world to realize the decentralization of enterprises, so we can learn more about it.

7.

The risk of any investment is directly proportional to the return. The key is whether you dare to participate in it. Of course, there are too many uncertainties in the current blockchain instry, not because of the instability of technology, but more because some insatiable people are black hearted and hard to defend

in my opinion, bitcoin is the most popular blockchain derivative currency at present, and there is no one. Then there are many other counterfeit currencies. If you hold some bitcoin now, but you are short of bitcoin, it is equivalent to a risk. And you are facing this risk. In the normal way, you can hardly short bitcoin to make profits, unless you do some up and down options to hedge the risk. I have done some short-term options in extreme NEW Europe, Long term options are not recommended, and few platforms can. Bitcoin doesn't operate in the same way as foreign exchange, so it has profit opportunities. When you are bullish, you can buy or hold money. When you are bearish, you can throw money. When you hold money, you can only hedge it by buying options, so the risk is relatively high

according to the current bitcoin market, if this position is at the bottom again at most, it will hit the top edge of the box. In short, this range fluctuation will increase. If there is a wait-and-see, you can wait until you fall to the bottom of the box and try to buy it. You must set a stop loss, or you will be confused when you are buried. If you think bitcoin is too expensive, you'd better find some options to get addicted to it