Blockchain consensus in the United States
e to the high network delay in peer-to-peer network, the transaction order observed by each node can not be completely consistent. Therefore, the blockchain system needs to design a mechanism to reach a consensus on the sequence of transactions that occur in the same time. This algorithm to reach consensus on the order of transactions in a time window is called consensus mechanism
-- chainknow
as a data structure that stores data in chronological order, blockchain can support different consensus mechanisms. Consensus mechanism is an important component of blockchain technology. The goal of blockchain consensus mechanism is to make all honest nodes keep consistent blockchain view, and satisfy two properties at the same time:
1) consistency. The prefix part of the blockchain saved by all honest nodes is exactly the same
2) effectiveness. The information released by one honest node will be recorded by all other honest nodes in their own blockchain.
one sentence introction: the more you do, the more you get
2. POS proof of stake
in a word: the more you hold, the more you get< Pbft: practical Byzantine fault tolerance
3. Pbft: practical Byzantine fault tolerance
Introction: it provides (n-1) / 3 fault tolerance on the premise of ensuring the activity and safety< Dbft: Byzantine fault tolerant algorithm authorized by delegated BFT
Introction: dbft mechanism adopted by ant is that bookkeepers are selected by rights and interests, and then bookkeepers reach a consensus through Byzantine fault tolerant algorithm
5. Pool verification pool
is based on traditional distributed consistency technology and data verification mechanism
chainnova is a blockchain company. I feel it's very good. Although I don't know any hash algorithm, I still know a little bit.
in a decentralized structural system, because the status of all participants is equal, when there are differences, how to reach consensus becomes a problem
therefore, a well-designed and easy to operate consensus mechanism is the key to the smooth self operation of a distributed system
in short, consensus mechanism is an algorithm to reach consensus on the sequence of things in a period of time. It is a mechanism for blockchain nodes to reach consensus on block information in the whole network.
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.
the biggest consensus of blockchain is to make money
there will be a process for the advancement of blockchain consensus. In the current flood and famine period, making money based on cognition and circle is still in consensus 1.0 stage. Fortunately, its size is not enough to affect the overall situation of the world economic structure, and the cost of supervision and policy intervention is low. In the large community of blockchain, more roles need to be involved, In particular, the government with service functions should not be absent, and the people in the community should not act like frightened birds, independent from the outside world
the bustling blockchain communities are not forests, but bird nests in a few trees at most. They chatter in order to grab food. Even if there is a third-class wind, everyone will be scattered. If you really want to dream of building a forest, you should bravely go down the tree, dig ditches and divert water
in the blockchain system, there is no centralized bookkeeping institution like a bank, so it is very important to ensure the consistency of each transaction on all bookkeeping nodes, that is, to make the whole network reach a consensus. The consensus mechanism solves this problem
at present, the main consensus mechanisms are workload proof mechanism POW and equity proof mechanism POS
POW determines your chances of getting bookkeeping rights by evaluating your workload. The greater the workload, the more likely you will get this bookkeeping opportunity
POS determines your chances of getting bookkeeping rights by evaluating the number and ration of tokens you hold. This is similar to the stock dividend system, holding a relatively large number of shares can get more dividends
the principle of dpos is similar to that of POS, except that some "deputies to the National People's Congress" are selected. The main difference from POS is that the node elects several agents, which are verified and recorded by the agents
with the development of technology, more advanced consensus mechanisms may emerge in the future.
blockchain is not only the core technology behind bitcoin, but also the infrastructure supporting bitcoin. Therefore, when talking about the consensus of blockchain, we must talk about the consensus of bitcoin
the core breakthrough of bitcoin is to reach a consensus on transaction events in the case of decentralization, that is, to reach an agreement on the effectiveness of a transaction without a central organization<
bitcoin's method to achieve this consensus mainly includes two parts:
incentive; That is, each block generates a certain amount of new bitcoin to motivate participants
introce external resources to ensure safety; That is, to ensure the security of consensus through a large number of external calculations, that is, proof of power
this is also the method adopted by almost all POW currencies. For example, dent, Wright coin, sand coin, dog coin and so on.
the consensus mechanism of blockchain is how to reach a consensus among all distributed nodes, generate and update data through the algorithm to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering
blockchain mainly includes four different consensus mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security.