Blockchain side chain record data

1. The degree of decentralization of public chain. This kind of public blockchain, represented by bitcoin and Ethereum, is not controlled by a third party. All people in the world can read the data records on the chain, participate in transactions and compete for the bookkeeping rights of new blocks
program developers have no right to interfere with users, and each participant (i.e. node) can freely join and exit the network, and carry out relevant operations according to their wishes
private blockchain is on the contrary. The write permission of the network is fully controlled by an organization or institution, and the data read permission is regulated by the organization, either open to the outside world or with a certain degree of access restrictions
in short, it can be understood as a weakly centralized or multi centralized system. Because the participating nodes are strictly limited and few; Compared with public chain, private chain has shorter time to reach consensus, faster transaction speed, higher efficiency and lower cost
the alliance chain is a blockchain between the public chain and the private chain, which can realize "partial decentralization"
each node in the chain usually has its corresponding entity or organization; Participants join the network through authorization and form a stakeholder alliance to jointly maintain the operation of the blockchain.

2. Bitcoin blockchain is a bitcoin blockchain? No, the block stores the transaction. In the early stage, you will get a coin if you successfully build a block. In the later stage, you can only get the fees paid by the exchange. A currency is a string of digital signatures. It is a digital signature sent by the last owner to the receiver. Everyone can see who owns the currency from the transaction
does each node have complete blockchain data? You mean a user node? A user node needs to keep the of the block head of the longest workload proof chain, so it knows the data of all the block heads. It can move forward to know all the data on the block chain, but not all of them are saved. A block header is very small, only 80 bytes, which can be saved completely, because the generation of nodes is very slow. Even with the passage of time, the amount is not too large now.

3. Toobi, it's a unilateral trading operation mode, very safe

4. The main chain is the underlying technology foundation of all blockchain applications, just like chips and operating systems. Whoever can become the main chain of the basic layer of the blockchain and accumulate a large number of users and scenes is likely to become the future giants such as apple and Microsoft
however, for most scenarios of using and developing blockchain, it is not necessary to re create a set of blockchain, as long as we develop our own applications based on the existing underlying blockchain or technical framework. Therefore, for the similar encryption algorithm, P2P technology, consensus algorithm, we only need to have a basic understanding, and do not need in-depth study
the primary goal of blockchain application development is to find a relatively mature underlying blockchain for application development. The underlying blockchain needs powerful and easy-to-use development interface or framework, scalability, transaction frequency, etc
Rong technology is a listed financial technology company, which currently provides main chain construction and development services http://www.erong.com/new/blockchain/backbone/index.html

5.

US annual report 2017 data have not yet been disclosed on the Internet. Only CEO Wang Xing told the public at Shanghai Center Tower that the sales volume of the US group network reached 360 billion yuan in 2017 and the income reached 33 billion yuan. In 2016, the turnover reached 240 billion yuan, an increase of 50% over 2015, and in 2017, it reached 360 billion yuan, an increase of 50% over 2016. Although judging from these data, meituan has developed rapidly, its financing frequency is also very high in recent years. What is the profit model of meituan

1. Commission

this is the most basic service of group buying websites, but it is different from foreign group buying websites. Foreign group buying websites usually buy goods from the merchants themselves and then sell them to earn the price difference, namely direct selling. Meituan is different. Basically, it only acts as the intermediary of the organizer, providing online promotion for cooperative businesses, and extracting a certain commission from the total amount of procts sold by businesses

meituan only uses group buying to establish its own basic business system, and takeout is only a consumption mode easily accepted by users in the current market under the whole catering category

6.

Hash function, also known as hash function and hash algorithm, is a method to create small digital "fingerprint" (also known as Digest) from any kind of data. What do you mean? That is to say, if you input data of any length and content, the hash function outputs a fixed length and fixed format result, which is similar to the fingerprint of the data you input. As long as the input changes, the fingerprint will change. Different content, the fingerprint obtained by hash function is different. This is the hash function

in distributed ledger, in order to ensure data integrity, hash value is used for verification. For example, a transaction or a page of ledger (that is, the concept of block) generates a summary after hashing, which means that the transaction information of the whole block cannot be tampered with (that is, the summary cannot be kept unchanged after tampering with the data)

the original definition or narrow sense of blockchain is in the form of block + chain, which is linked by hash. Each block may have many transactions, and the whole block can generate summary information through hash function, and then each block needs to record the summary information of the previous block, so that all blocks can be connected into a chain

if you change the data of a block in the history, it means that the block summary value (i.e. hash value) will change, then the hash of the previous block recorded in the next block will have to be modified accordingly, and so on. That is to say, if you want to modify the history, you need to start from that point, and then all records will have to be modified to ensure the legitimacy of the ledger, Hash function increases the difficulty of account book tampering

the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system

7.

The current development stage of blockchain Technology: financial value period, credit value period and governance value period. Among them, blockchain 3.0 and 4.0 are developing rapidly. It is predicted that there will be a wave of great changes in blockchain technology

ecology makes the main chain and the side chain

ecol ecology makes the team deal with the difficulties faced by the side chain. Through data isolation and cross chain audit, the business data confidentiality and security of the side chain can be guaranteed, and the balance between data transparency and business confidentiality can be solved

and support multi side chain, main side chain communication, asset transfer, both integration and division of labor, both security and convenience. The main chain is mainly responsible for security and consensus. The side chain will provide smart contracts, token issuance, asset trading, cross chain interoperability, and the structure of the main and side chains. Through slimming and pruning technology, it can effectively prevent block swelling, garbage accumulation, and shorten synchronization time. To clear the obstacles for the implementation of high concurrency and lightning network

ecol ecol makes it possible to connect different blockchains through side chain technology, which is the key to solve the problem of slow transmission speed and low efficiency in expanding the external structure of blockchain. In short, the side chain is like a channel, connecting different blockchains together to realize the expansion of blockchain. In the long run, ecolink will graally build a high-speed value Internet belonging to the side chain in the case of developing, applying and proposing solutions