Blockchain data consensus
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.
1. Physical security
the network and host running the blockchain system should be in a protected environment. According to the regulatory requirements of specific business, the protection measures can be used to protect the physical network and host by means of VPN, firewall, physical isolation, etc
2. Data security
in principle, the data exchange between nodes of the blockchain should not be transmitted in clear text. For example, asymmetric encryption can be used to negotiate key, and symmetric encryption algorithm can be used to encrypt and decrypt data. The data provider should also strictly evaluate the sensitivity and security level of the data, decide whether to send the data to the blockchain, whether to desensitize the data, and adopt strict access control measures
3. Application system security
application system security needs to start from the aspects of identity authentication, authority system, transaction rules, anti fraud strategy, etc.
relevant personnel, transaction nodes and transaction data involved in application operation should be controlled in advance and auditable afterwards. Taking financial blockchain as an example, consensus algorithm with stronger fault tolerance, anti fraud and higher performance can be adopted to avoid joint fraud of some nodes
4. Key security
to encrypt the communication data between the blockchain nodes and the key to encrypt the data stored on the blockchain nodes, the plaintext should not exist on the same node, and the private key should be properly saved by the encryption machine. When the key is lost or leaked, the system can identify the relevant records of the original key, such as account control, communication encryption, data storage encryption, etc., and implement response measures to make the original key invalid. The key should also be managed strictly in the life cycle, and should not be permanently valid. It needs to be replaced after reaching a certain time cycle
5. Risk control mechanism
there should be careful detection measures for the network layer, host operation, data access of application system, transaction frequency and other dimensions of the system. For any suspicious operation, alarm, record and verification should be carried out. If illegal operation is found, loss assessment should be carried out, remedial measures should be taken at the technical and business levels, and security measures should be strengthened, And trace the source of illegal operation to prevent further attacks
Article source: white paper on blockchain technology and application development in China
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
consensus mechanism refers to the algorithms, protocols and rules that define the consensus process
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 a decentralized distributed ledger system. Due to the high network delay in the 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 a certain period of time. This algorithm to reach consensus on the order of transactions in a time window is called consensus mechanism.