Ethereum side chain SKL

1.

There is an essential difference between Ethereum and bitcoin. What is the difference? Bitcoin defines a set of currency system, while Ethereum focuses on building a main chain (which can be understood as a road) to allow a large number of blockchain applications to run on this road

from this point of view, Ethereum's application scenarios are more extensive, which is why we say that Ethereum marks a simple monetary system in the era of blockchain

1.0, and a transformation to other instries and application scenarios in the era of blockchain 2.0

however, there is no perfect thing in the world. Although Ethereum has expanded the application scope of blockchain in all walks of life and improved the speed of transaction processing, it also has some disputes and doubts

first, the solution to the lack of scalability of Ethereum: slicing technology and lightning network

the bottom design of Ethereum, the biggest problem is that Ethereum has only one chain and no side chain, which means that all programs have to run on this chain equally, consuming resources and causing system congestion. Just like last year's very popular Ethereum game "encryption cat", when this game was very popular, it once caused Ethereum network paralysis

to improve the processing capacity, Ethereum proposes two ways: shard and lightning network. Let's introce these two technologies respectively

(1) fragmentation technology

vitalik buterin, founder of Ethereum, believes that the reason why mainstream blockchain networks such as bitcoin process transactions very slowly is that every miner has to process every transaction in the whole network, which is actually very inefficient. The idea of fragmentation technology is: a transaction does not need to be processed by all nodes in the whole network, as long as some nodes (miners) in the network are allowed to process it. Therefore, Ethereum network is divided into many pieces. At the same time, each piece can handle different transactions. In this way, the network performance will be greatly improved

however, the slicing technology is also controversial. As we all know, the important idea of blockchain technology is decentralization. Only when the whole network witnesses (processes) the same transaction can it have the highest authority. The Ethereum slicing technology is similar to the group witness, not all nodes witness together. In this way, it will lose the absolute "decentralization" attribute, and can only achieve the purpose of high performance by sacrificing certain characteristics of decentralization

(2) lightning network

lightning network uses the way of transaction under the chain. What does that mean? It means: when the participants of lightning network transfer money to each other, they do not need to confirm the transaction through the main chain of Ethereum, but create a payment channel between the participants and complete it under the chain

however, lightning network is not separated from the main chain. Before establishing a payment channel, you need to use the assets on the main chain as collateral to generate a balance proof, which indicates that you can transfer the corresponding balance. In the case that both parties of the transaction hold the balance certificate, both parties can make unlimited number of transfers under the chain through the payment channel

only when the off chain transaction is completed and the assets need to be transferred back to the chain, the balance change information of the main chain account will be registered on the Ethereum main chain, and no matter how many transactions occur ring this period, there will be no record on the main chain

another real benefit of lightning network is that it can save the cost of miners for you. At present, when we trade on the main chain of Ethereum, we need to consume gas and pay for miners. Once we move the transaction to the lower chain, we can save this part of the cost

Of course, lightning network is not perfect. When using the lightning network, the assets on the main chain should be used as collateral; And this part of assets as collateral can not be used before the user completes the transaction under the chain. This also determines that lightning trading is only suitable for small transactions

the above is the problem of insufficient scalability of Ethereum, as well as the two main solutions: fragmentation technology and lightning network

Second, there are loopholes in Ethereum's smart contract and the infamous Dao event

Ethereum's smart contract is very powerful, but there are loopholes in any code. The biggest controversy of Ethereum's smart contract lies in the so-called loopholes, that is, security issues. According to relevant research, 34200 (about 3%) of the nearly 1 million smart contracts based on Ethereum contain security vulnerabilities, which will allow hackers to steal eth, freeze assets or delete contracts, such as the infamous Dao incident

(1) what does Dao mean

before introcing the Dao event, let's first introce what Dao is. Dao is the abbreviation of decentralized

autonomous organization, which can be understood as decentralized autonomous organization. From the perspective of Ethereum, Dao is a kind of contract or a combination of contracts on the blockchain, which is used to replace the government's review and complex intermediate proceres, so as to achieve an efficient and decentralized trust system. Therefore, Dao is not a specific organization, that is to say, there can be many Dao, all kinds of Dao

(2) the infamous Dao event

however, when we talk about Dao now, we basically refer to the Dao event, that is, the infamous hacker attack event we just mentioned. As we know, the English word "the" refers to "the Dao event". The Dao event

refers to "the Dao event", because we just said that Dao is not a specific organization, there can be many Dao, all kinds of Dao

in 2016, slock.it, a German company focusing on "smart locks", launched the Dao project on Ethereum in order to realize decentralized physical exchange (such as apartments and ships). Since April 30, 2016, the financing window has been open for 28 days

unexpectedly, this Dao project is very popular. It raised more than US $100 million in just half a month. By the end of the whole financing period, it raised a total of US $150 million. Therefore, it has become the largest crowdfunding project in history. However, it didn't last long. In June, hackers took advantage of the loopholes in the smart contract to successfully transfer more than 3.6 million Ethernet coins and put them into a Dao sub organization, which has the same structure as the Dao. At that time, the price of Ethernet currency fell directly from more than $20 to less than $13

this event shows that there are loopholes in smart contracts, and once the loopholes are exploited by hackers, the consequences will be very serious. This is why many people criticize Ethereum and say that its smart contract is not smart

to solve this problem, many foreign companies begin to provide code audit services in order to solve the vulnerability problem of smart contract. From a technical point of view, some teams are currently testing smart contracts. Most of these teams are led by professors from Harvard, Stanford and Yale, and some of them have obtained investment from leading institutions

in addition to the problems of insufficient expansibility and loopholes in smart contracts, the controversy over Ethereum lies in the POS consensus mechanism it pursues, that is, the proof of equity mechanism. Under the proof of equity mechanism, if anyone holds more money and holds it for a longer time, he will get more "rights" (interests) and have the opportunity to get bookkeeping power, Bookkeeping can also be rewarded. In this way, it is easy to create the oligarchic advantage of "the stronger the stronger"

Another problem is the chaos of ICO. ICO is a common way to raise funds for blockchain projects, which we can understand as pre-sale. The outbreak of ICO projects on Ethereum has caused illegal activities such as fund allocation and money fraud under the banner of ICO, which has caused security risks to social and financial stability

2. Ethereum blockchain has exposed three major problems, and its founder vitalik buterin has been unable to interpret them for a long time. The first is the low performance and TPS of Ethereum blockchain as a whole; The second is that resources are not isolated. The event of cryptokitties virtual cat once occupied 20% of the traffic of the whole Ethereum, which directly caused Ethereum network users unable to carry out timely transactions, which is the biggest pain point of resources not isolated; The third problem lies in the embodiment of Ethereum's governance structure. As a decentralized distributed ledger, the founder team of Ethereum has dominated its network development in the past. The over centralized governance mode has led to the bifurcation of eth, etc and ETF in Ethereum, and the Ethereum community is now in a state of fragmented governance. In the view of Ma Haobo, founder and CEO of "aelf", all kinds of disadvantages of Ethereum are unacceptable. Therefore, the positioning of "aelf" is born for the next generation of decentralized underlying computing platform of Ethereum, which focuses on solving the problems of insufficient performance, non isolation of resources and governance structure of Ethereum.

3.

This is two different concepts. According to different standards, blockchain can be classified into three categories:

& # 8195&# 8195; 1) According to the network scope of blockchain, it can be divided into public chain, private chain and alliance chain

 &# 8195; 2) According to the docking type of blockchain, it is divided into single chain, side chain and interconnection chain

 &# 8195; 3) According to the display environment of blockchain deployment, it can be divided into main chain and test chain

the main chain can be understood as a formal online and independent blockchain network, while the public chain refers to a blockchain that can be read by anyone, can send transactions and can be effectively confirmed by anyone, and can participate in its consensus process

4. 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.

5.

Link

< H2 > 1. Introction

link is the erc20 standardized token based on Ethereum blockchain, which is used to pay the chainlink node operators, so as to retrieve data from the data of the chain off, format the data into the readable format of the blockchain, calculate the chain off and ensure the normal running time. Chainlink token, as a part of the running node, can prevent undesirable participants

< H2 > 2. Project introction

the first distributed Oracle network, which allows anyone to safely provide smart contracts, access key external data, offline payment and any other API functions. Any user with a data feed, offline service (such as local payment) or any other API can directly provide it to a smart contract in exchange for a link token. Chainlink network is a distributed network of chainlink nodes, which directly transport specific data, API and various offline payment functions to smart contracts. Chainlink network is composed of two independent parts, on chain and off chain, which must interact to provide services. The network is built in such a way that it can be upgraded, so that it can replace its different components when better technologies and technologies emerge. The chain components of the network filter Oracle through service level agreement (SLA) based on the measurement of one party's request of smart contract. Using these metrics, chainlink collects responses to SLA queries, sorts them using reputation and aggregation models, and provides final set results of chainlink queries that may be implemented in smart contracts. The out of chain components of the network are composed of Oracle nodes connected to the Ethereum network, which independently collect responses to offline requests. These off link nodes can be located in any instry. For example, the off link nodes operated by the New York stock exchange can provide real-time and accurate transaction information for the chainlink network, or the off link nodes of the visa network can solve transactions and interact with consumers and suppliers through the chainlink network. Chainlink technology aims to integrate nodes from all these instries into a common network, which itself acts as a (low-cost) middleman, interpreting and allocating data correctly as needed. The chainlink system will ensure that the results obtained from the Oracle are accurate and allow the oracle to remain independent of the data they provide. Any data, payment, e-signature or other API providers and personal developers can easily join the chainlink network by connecting their familiar API to the network. Once the API is connected to the chainlink, the user becomes the chainlink node operator and is responsible for connecting the API to the chainlink network. In order to motivate operators to provide API information, they are compensated in the link token to successfully complete the online link request. The project currently provides a fully distributed Oracle network compatible with bitcoin, Ethereum and hyperledger. It is expected that other blockchains will be supported in the future, which will allow cross chain connections between smart contracts and any other public or private chains, and allow anyone in the world to use the chainlink network, regardless of its platform. All service providers will be able to securely provide smart contracts to access critical external data and possibly even non chained payments

< H2 > 3. Comment

chainlink (link) is a decentralized network, which can provide information (Oracle) for smart contracts. Chainlink was established by Sergey Nazarov and Steve Ellis in 2017, aiming to solve the problem of information procurement under the chain through smart contract for its execution parameters. Smart contract is designed to execute automatically when some parameters are satisfied. However, when these parameters exist under the chain, it depends on the information source (called Oracle) to provide the necessary information. Off chain predictors are often centralized and rely on third parties to provide critical information in a reliable and time-consuming manner. Chainlink aims to break this dependence by providing information to smart contracts through a decentralized prediction network. These predictions work together on the link blockchain to verify and forward key information to these contracts. Chainlink network allows users with data feeds or information hosting APIs to easily provide information to smart contracts in exchange for link tokens< memorabilia September 2017 - chainlink ICO. November 2018 - acquisition of town crier (smart contract and data privacy project). June 13, 2019 - announced cooperation with Google utility link network to provide timely and accurate information to smart contracts through Oracle's distributed network (data sources and APIs). This information is very important for the effective and accurate execution of smart contracts, because the required information exists under the chain, and there must be a reliable way to obtain the information on the chain. The link token is used as payment for smart contracts that use the data provided by the link network, in which the oracle that provides accurate information will be rewarded in proportion to the link< important functions partnership with major instry players such as swift and Google, integration of Ethereum side chain, such as harmony, celer and matic. Average block time n / A; The total supply is 1 billion link; Write Oracle consensus to Ethereum blockchain through threshold signature

related links: https://chain.link/

https://en.bitcoinwiki.org/wiki/ChainLink

https://everipedia.org/wiki/lang_ en/chainlink-cryptocurrency

https://blog.chain.link/threshold-signatures-in-chainlink/

https://blockonomi.com/chainlink-guide/

 

6.

An important reason for the popularity of "virtual currency" in China is the lack of multi-level and multi category investment market, which makes many investors choose speculative procts such as "virtual currency"

therefore, China should also pay close attention to the construction of e-money system and virtual currency in line with the background of the times, improve the supervision of the investment market and the new financial technology system, and make good use of financial technology on the premise of preventing financial risks, so that it can better serve the real economy

in the face of the rapid development of Internet Finance and financial technology, relevant departments need to do a solid job in risk prevention and control while encouraging innovation. In order to regulate the development of this virtual commodity better and make its transaction in the market truly based on the use value, we should build special regulatory measures and even institutions for innovation such as "virtual currency" on the existing basis

7. Generally, blockchain, especially public chain, has main network and test network. The main network is a trusted blockchain network recognized by the blockchain community, and its transaction information is recognized by all members. Effective blocks will be added to the block ledger of the main network after the consensus of the blockchain network
many people don't understand what side chain is. This concept comes from bitcoin community and was put forward in December 2013. There are some problems with the birth of bitcoin itself or the mechanism of a blockchain itself. But if you modify bitcoin protocol or chain directly, it is easy to make mistakes. Moreover, because the bitcoin block has been operating continuously, if it is wrong, the amount of funds involved will be very large, which is not allowed
in fact, sidechains do not refer to a particular blockchain, but to all blockchains that comply with the side chain protocol. This term is relative to the main chain of bitcoin
for more information, what is a side chain

8.

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

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