Implementation of side chain in blockchain
the purpose of the side chain is to achieve two-way anchoring, so that some cryptocurrency can be "transferred" between the main chain and the side chain. Take bitcoin as an example: through the side chain technology, bitcoin can be "transferred" from the main chain to other blockchains, and can be used on the "transferred" blockchain. At the same time, bitcoin can safely "return" to the main chain; Bitcoin keeps the same value throughout the process. Therefore, the concept of side chain is relative to the main chain; As long as it conforms to the side chain protocol, all existing blockchains, such as Ethereum, lightcoin, zcash, etc., can become side chains
the deployment of side chain technology on the main chain means that users can use their existing assets to access the new cryptocurrency system, so as to achieve the operation purpose that cannot be achieved on the main chain. For example, using rootstock technology will enable bitcoin to conct more complex transaction operations, such as micro payment, through smart contract technology. At the same time, cryptocurrency can also expand its application scope through two-way circulation in the main chain and side chain
on the other hand, because the side chain is an independent blockchain and has its own node network, the code and data are relatively independent; So it will not increase the burden of the main chain in the process of running, to avoid the situation of excessive data expansion. However, the side chain technology is more complex, and it needs to support scripts that can be later reorganized to prove failed transactions and enough running nodes to ensure its security.
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
Meituan belongs to BTC type
BTC (business to customer) is one of the categories of e-commerce according to the trading partners, which means the e-commerce of commercial institutions to consumers
this form of e-commerce is generally based on online retail instry, mainly relying on the Internet to carry out online sales activities
BTC is also called B2C. B2C mode is the earliest e-commerce mode in China 
extended information:
the payment method of B2C e-commerce is the combination of cash on delivery and online payment, while most enterprises choose logistics outsourcing to save operating costs
with the change of users' consumption habits and the promotion of excellent enterprise demonstration effect, the number of online shopping users is increasing. In addition, some large-scale examinations such as the civil service examination also began to implement B2C mode
its basic needs include user management needs, customer needs and vendor needs
user management requirements: user registration and user information management
customer needs: provide electronic directory to help users search and find the goods they need
compare similar procts to help users make purchase decisions
evaluate goods, add shopping cart, place order, cancel and modify order
be able to pay online; Track the status of the order
seller's needs: check the customer's registration information
process customer orders
complete the settlement of procts purchased by customers and process customer payment
be able to publish commodity information, publish and manage online advertising
establish an interface with the bank for electronic auction
inventory management
establish interface with logistics distribution system
be able to track proct sales
to achieve customer relationship management
provide after-sales service
The side chain is another blockchain outside the main chain, which anchors a node in the main chain, maintains the authenticity of the side chain through the computing power on the main chain, and realizes the transfer of the value on the public blockchain and the value on other account books among multiple blockchains. Blockstream is the most representative implementation. In this kind of blockchain architecture, the main chain is sometimes called parent chain
Main chain: an independent blockchain network officially launched. It can be said that the entity of blockchain storing data is generally considered to be the main chain network itself. For example, BTC main network, ETH main network and EOS main network are main chains
side chain: first of all, the essence of side chain protocol is a cross block chain solution. In short, through this scheme, data information can be transferred between two blockchains. The original proposal of side chain is based on the transfer of bitcoin and other digital assets among multiple blockchains
generally speaking, the side chain is like a channel, connecting different blockchains together to realize the expansion of blockchain. The side chain is completely independent of the main chain, but the two books can "operate with each other" to achieve interaction
side chain protocol - side chain protocol refers to (take bitcoin as an example): it can safely transfer bitcoin from the main bitcoin chain to other blockchains, and also can safely return to the main bitcoin chain from other blockchains. The same is true here for bitcoin to Ethernet or other blockchains. Then, why do we need side chain, or what are the advantages of side chain
the function that the main chain lacks is provided by the side chain
for example, bitcoin network does not have the function of smart contract, but it can achieve this function through the side chain
if the operation efficiency of the main chain is low, some functions of the main chain can be transferred to the side chain
for example, the transfer speed of the main chain is very slow, and there is no way to meet the daily payment needs. We can develop the lightning network as the side chain to meet the daily payment needs. Also because of low performance, Ethereum can not support large commercial DAPP (decentralized application), which can be realized through side chain development
if we put aside the technical rigor, we can use another simpler way to understand the side chain. All the networks that provide support or services for the original primary network can be called side chain, regardless of whether the side chain adopts blockchain technology. For example, the
third party payment network (Alipay / WeChat) can imagine the banking network as the main chain while the third party payment is a side chain.
for cryptocurrency trading, the free network such as bitcoin and other virtual currencies can be regarded as the main chain, and the exchange can be regarded as a side chain
RSK and loom are separately developed side chains for bitcoin and Ethereum main chain
in the first application, both the main chain and the side chain are centralized
in the second application, the main chain is decentralized and the side chain is centralized
in the third application, the main chain is decentralized and the side chain is also decentralized. With the deepening of blockchain technology, we can see the value exchange activities of human beings, It will graally transition from the first application to the third application
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