区块链 staking,sol 区块链

区块链staking和sol区块链技术是比特币和其他区块链系统的基础。在本文中，我们将介绍staking、sol区块链和智能合约的三个关键概念。

Staking：Staking是一种区块链技术，它可以帮助用户获得报酬，以支持区块链网络。Staking的工作原理是，用户将自己的资产抵押给区块链网络，以参与网络的共识机制。用户将自己的资产锁定在区块链网络中，以支持网络的运行，并获得报酬。Staking技术可以降低区块链网络的运行成本，并可以降低攻击者的攻击成本。

Sol区块链：Sol区块链是一种新型的区块链技术，它使用智能合约来实现去中心化的应用。Sol区块链是一种开放源代码的区块链技术，它使用智能合约来实现去中心化的应用。Sol区块链技术可以让开发者构建和部署去中心化的应用程序，而无需依赖中心化的服务器或第三方服务提供商。Sol区块链技术的安全性也更高，因为它使用了密码学技术来确保数据的安全性。

智能合约：智能合约是一种可以在区块链网络上执行的自动执行的协议。智能合约可以在区块链网络上执行，从而实现去中心化的应用。智能合约可以用来实现自动执行的交易，从而实现去中心化的应用。智能合约可以用来实现去中心化的支付系统，以及去中心化的投票系统等。智能合约可以提高数据安全性，并可以减少交易成本。

以上就是staking、sol区块链和智能合约的三个关键概念。Staking可以帮助用户获得报酬，以支持区块链网络；Sol区块链可以让开发者构建和部署去中心化的应用程序；智能合约可以用来实现去中心化的支付系统，以及去中心化的投票系统等。这些技术可以帮助用户实现安全、高效的区块链应用。

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A. What are the mainstream blockchain technologies?

This article attempts to provide an overview of blockchain-related technology schools and mainstream platforms as a guide for learning the blockchain technology system. The purpose of this review is to attract new ideas and promote discussion and consensus in the blockchain development community. The schools of blockchain technology plan ahead of the battle. If you want to invest in the field of blockchain development, you must at least find out who the current players are and what their respective opinions and strengths are. There are no certain rules for dividing blockchain technology schools. As far as I can see, there may be the following four ways: The first is to divide it into public chain, private chain and alliance chain according to the node access rules. The representatives of the public chain are naturally Bitcoin and Ethereum, the private chain is the most famous R3 Corda, and the representative work of the alliance chain is Fabric under the name of Hyperledger. Public chains focus on anonymity and decentralization, while private chains and consortium chains focus on high efficiency, and often set entry barriers. These differences between public chains, private chains and alliance chains are all reflected in technology. For example, private chains and alliance chains assume that the number of nodes is not large, and the PBFT algorithm can be used to form a consensus. The public chain assumes a large and dynamically changing node network. Using PBFT is too inefficient, and only a lottery-like algorithm can be used to determine opinion leaders. This means that it is difficult for private chains and alliance chains to become public chains, and although it is easy to use public chains to make alliance chains or private chains, it is not plug-and-play. Scholars cannot ignore this difference. The second is that according to the sharing goal, it is divided into two groups: shared ledger and shared state machine. Bitcoin is a typical shared ledger, and Chain and BigchainDB should also fall into this category. These blockchain systems share a general ledger between various nodes, so it is more convenient to connect with financial applications. In another large type of blockchain system, each node shares a state machine that can complete Turing complete calculations, such as Ethereum and Fabric. They all change the state of the shared state machine by executing smart contracts, thereby achieving various complex functions. . The third is to divide the blockchain system into three generations: 1.0, 2.0 and 3.0 according to the intergenerational evolution described by Melanie Swann. Among them, 1.0 supports decentralized trading and payment systems, 2.0 supports industry applications through smart contracts, and 3.0 supports decentralized social systems. Bitcoin and Chain should belong to the blockchain 1.0 system, while Ethereum and Fabric are blockchain 2.0 systems. There is currently no successful blockchain 3.0 system, but there is one unsuccessful attempt, which is the famous The DAO . The fourth is that according to the core data structure, it is divided into two factions: blockchain and distributed ledger. The blockchain school really implements a chain of blocks as the core data structure in the system, while the distributed ledger school only absorbs the spirit of the blockchain and does not really use a blockchain as the core data structure. , or although it is temporarily used, it is stated that the Zhuangwu blockchain is intended to be a distributed ledger. If time and opportunity come together, it may not be impossible to replace it. Understanding of mainstream blockchain technology platformsThe classification of schools can still only be used to point out the country and boast. To start, there must be an entry point. It is said that there are thousands of blockchain currencies, but there are only dozens of technology platforms worth paying attention to. If you want to enter the field of blockchain development, lay a good foundation, practice good skills, and get a few good ones. offer, there are only a handful of platforms worthy of in-depth study and study. The first, of course, is Bitcoin. As the first and most successful and important model project of the blockchain, Bitcoin has been online for more than eight years without any serious security and operation and maintenance incidents. Its stability and power can be called contemporary software. System model. Bitcoin Core is an open source software with high code quality and good documentation. From the perspective of learning blockchain principles and mastering core technologies, Bitcoin Core is the best entry point to learn authentic blockchain technology. . Of course, Bitcoin Core is written in C++, and uses some C++11 and Boost library mechanisms, which puts higher requirements on learners' C++ level. Another advantage of learning Bitcoin platform development is that you can connect with the prosperous Bitcoin technology community. There are currently many people working on improving and upgrading Bitcoin. The more people there are, the more power there is. Newer ideas and technologies such as Segregated Verification, Lightning Network, and Sidechains have all taken the lead in being implemented in the Bitcoin community. For example, Blockstream, the main leader of sidechain technology, is led by cryptocurrency veteran Adam Back, and Blockstream is one of the largest contributors to Bitcoin Core, so some sidechain-related technologies are the most discussed in the Bitcoin community. However, there is great controversy as to whether Bitcoin, as a typical blockchain 1.0 system, is the best technical platform to support other types of blockchain applications. In addition, not everyone has the ability and necessity to be proficient in the underlying technology of blockchain. So for those who are eager to rush into the blockchain field to do (quān) things (qián), the more straightforward learning goals may be Ethereum and Hyperledger Fabric. Smart contract development using Solidity on Ethereum is the easiest way to get into blockchain development, bar none. Ethereum's ideals are very grand. Because it is equipped with a powerful Turing-complete smart contract virtual machine, it can become the mother platform of all blockchain projects and is the big turtle that carries the entire blockchain world. Developing a cryptocurrency similar to Bitcoin on Ethereum is an out-and-out small goal. Generally, experienced developers can get started with the guidance of the documentation in half a day to a day. The question is, what happens after you get started? Can you conquer the world just by writing Solidity? This is highly doubtful. We can also say the other way around, if Ethereum + Solidity is the ultimate solution for blockchain, then why are there so many blockchain technology schools? In particular, Ethereum doesn’t seem to give the giant real-world centralized groupThis completely uncompromising revolutionary attitude may also become an obstacle to the promotion of Ethereum. The current development of the Ethereum project is not going well. A more prominent problem is that there are too many projects and power is dispersed, resulting in uneven project quality. But despite this, compared with other blockchain 2.0 platforms, the development environment provided by Ethereum is the simplest and most complete. It is absolutely necessary for people who are new to blockchain to learn Ethereum to establish the most "authentic" understanding of blockchain and smart contracts. The third branch of the mainstream blockchain technology platform is Fabric, which is Hyperledger’s first and most well-known incubation project. Fabric first came from IBM's Open Blockchain project. By November 2015, IBM handed over the 44,000 lines of Go language code that had been developed to the Linux Foundation and incorporated it into the Hyperledger project. During a hackathon in March 2016, Blockstream and DAH merged their respective codes into Open Blockchain, which was later renamed Fabric. So far, Fabric and Sawtooth Lake provided by Intel are listed as the first-level incubation projects of Hyperledger, but the former has received far more attention than the latter. From a technical perspective, Fabric has a good idea, and its focus is to meet the commercial needs of enterprises, such as solving transaction volume issues. As we all know, Bitcoin’s biggest shortcoming is its upper limit of 7 transactions per second, which is completely unable to meet practical needs. Fabric's goal is to achieve 100,000 transactions per second, which is close to the instantaneous peak of the Double Eleven transaction volume that just passed, and can fully meet industry-level applications under normal conditions. Fabric is developed in Go language and also provides APIs in multiple languages. It is particularly worth mentioning that Fabric makes full use of container technology. For example, its smart contracts run in containers. This is also a benefit that Go language brings to Fabric, because the static compilation and deployment characteristics of Go language are very suitable for developing programs in containers. Fabric also has some features, such as its membership service that can set up node access review, which is a typical alliance chain feature. Another example is that its consensus algorithm is customizable. The shortcoming of Fabric is that the system is relatively complex. Although it has documentation, it is difficult for developers who lack experience to learn it. However, because of its clear positioning and catering to the mentality of many companies, many institutions are already secretly developing alliance chain projects in the industry based on Fabric.

B. Blockchain financial application

Blockchain financial application is a key area where it plays a role in reality. The financial industry needs such high-end technology, and traditional operating methods will Profound changes have occurred because of such technology. Blockchain financial applications have many distinctive features, which make people talk about it, and it has become more popular because of its actual effects.attention and had an increasing impact.

Abstract: Developed countries and technology companies have taken the lead in the research and application of blockchain technology. Judging from the application of patent technology, there may be a gap of about one and a half years between my country and the United States in blockchain technology. Based on the above situation, how can China achieve "asymmetric" catch-up? The first thing is to see the situation clearly, seize opportunities and meet challenges. Secondly, after understanding the necessity of the underlying construction of blockchain for the existing business and future development of the financial industry, a consensus was reached among various financial companies to establish a "China's Financial Blockchain Alliance". The last step is to advance collaboratively and embrace change.

How to understand blockchain?

Bitcoin: A peer-to-peer electronic cash system. In 2009, after the paper was published, Bitcoin was born as a virtual currency in the digital world of the Internet. At present, the total market value of Bitcoin is about US$6.5 billion. Although the market value is constantly changing, it is still the largest virtual currency in the world.

Another important concept is blockchain. Blockchain is an underlying technology of Bitcoin, and Bitcoin is just an application of blockchain. As we all know, Bitcoin can realize point-to-point value transfer. In addition to the Bitcoin blockchain, there are many other blockchains, such as the Ethereum blockchain, etc. Therefore, we should distinguish between concepts such as Bitcoin, Bitcoin blockchain, blockchain, and blockchain technology.

Currently, people have several misunderstandings about blockchain. Blockchain can be described in English as "Decentralized Blockchain", where Decentralized is translated as "decentralized". However, I think the blockchain has realized the unintermediary dissemination of value, which is point-to-point value dissemination. This does not mean that after entering the blockchain era, there is no need for a center, but that it should move from a single centralization to a center and a center. parallel development. Then, the existing center is likely to become a branch center or a weak center. Currently, all banks have their own data centers. If a financial blockchain alliance is established in the future, they can become nodes in the blockchain alliance, so blockchain does not require a center.

Blockchain does not require credit

We often see some articles that believe that blockchain needs to “remove credit”. In fact, blockchain relies on consensus The algorithm builds trust and ensures the correctness of transactions through consensus among nodes. Build trust at low cost through mathematics and algorithms instead of "removing credit". However, digital asset transactions between people do not require two people to know each other or have a trust relationship with each other, nor does it require a third-party credit agency. It only requires everyone to trust the trusted network of the blockchain.

Why is it considered credible? Because it is a distributed database, it has a consensus-based mechanism: a set of encryption algorithms, making it immutable. on the one handThe public key makes information transparent and traceable; on the other hand, the private key can protect privacy.

Blockchain is not a mature technology, nor is it omnipotent. Blockchain technology is still in its early stages of development. At the beginning of this year, we sent a delegation to Barclays South Africa’s blockchain research laboratory to study. During the seminar, Barclays African blockchain experts believed that it will take at least five to ten years for blockchain technology to become a truly mature technology. At present, blockchain has the disadvantages of relatively slow computing speed and small storage space. Moreover, not all data processing requires the use of blockchain.

Research and application of blockchain in foreign countries

We found that established financial developed countries are already leading the way in the research of blockchain technology. The British government believes that it is very important for the government to participate in the legislation of digital currencies and blockchain networks, and the government encourages in-depth research on blockchain technology. The British government is actively evaluating the potential of blockchain technology and considering its use to reduce financial fraud and reduce costs. In addition, the UK government plans to develop application systems that can be used between government and public agencies.

In February this year, the European Commission placed cryptocurrency at the top of the list of rapid development target areas. This initiative promoted policy research on digital currencies by various agencies. Technology companies are also leading the way in research on blockchain technology.

IBM launched the "Open Ledger Project" to develop an enterprise-level blockchain software structure and promote the commercial use of blockchain technology through the Bluemix and API foundation of the IBM cloud computing platform. Architecture to support the docking of external data. IBM still has a lot of practice in blockchain technology. Recently, it and a company in South Korea conducted creative experiments using blockchain technology and the Internet of Things, and achieved some results.

Microsoft uses the Azure platform to provide users with "blockchain as a service", which can enable R3 and its bank members to speed up the experiment and learning process, and accelerate the development, testing and deployment of distributed ledgers.

Intel also released SawtoothLake, an efficient modular platform for building, deploying and running distributed ledgers; at the same time, Intel is also studying to create a trusted execution environment for hardware chips for blockchain applications, providing Greater security and privacy.

Meanwhile, Wall Street is also taking action. Although founded relatively late, R3’s core function is to formulate industry standards for the development of blockchain technology in the banking industry, as well as explore practical uses and establish a blockchain alliance for banks.

From what we know, in addition to these two new companies on Wall Street catering to the digital financial era, large financial institutions are studying blockchain technology and building their own areas. Blockchain concept and technology team.

Currently, blockchainThe technology already has practical application cases.

In Canada, the blockchain startup company "Blockchain Tech Ltd" has successfully been listed on the Toronto Stock Exchange GEM; the Estonian government will launch the government's blockchain medical insurance Record.

Domestic attention and research on blockchain technology

Blockchain is an optional technology. Previously, the People's Bank of China also held a digital currency seminar. In addition to the central bank, relevant departments such as Zhejiang Province and Beijing Municipality also expressed support for blockchain application research last year.

From an enterprise perspective, Bubi blockchain has been used in equity, supply chain, points and other fields, and is currently conducting trials and application tests with exchanges and banks. Bubi Blockchain focuses on the innovation of blockchain technology and products. It already possesses a number of core technologies and has developed its own blockchain service platform. And many blockchain innovative and entrepreneurial companies are constantly emerging.

In addition, a number of industry alliances are being established. In terms of financial institutions, the current cases of blockchain application by my country's large banks and financial institutions still need to be solved.
At the end of 2015, Bank of America had obtained 15 patents on blockchain. There may be a gap of about one and a half years between my country and the United States in blockchain technology.
Blockchain financial applications are entering a new stage in an all-round way. Various applications will become more and more in-depth, and related changes will attract more and more attention, and a huge new trend will form. .

C. Blockchain Alliance Chain (3) Understanding Fabric

Fabric is the core blockchain framework launched by the Hyperledger Alliance. It is suitable for complex enterprises and between enterprises. Build an alliance chain. According to the goals of the Hyperledger Alliance, Fabric is built as a modular basic alliance chain framework that supports pluggable components. ;

Unlike Ethereum-based Quorum, Fabric only considered inter-enterprise applications from the beginning. Its unique channel concept connects enterprises in different subnets according to different business purposes. Each subnet corresponds to a channel, and each channel has its own independent blockchain. Quorum obviously has only one public network (all enterprise nodes join it), and private business between enterprises is completed through Private Manager.

The simplest way to understand channel is to analogize it to a Topic provided by a message service. In fact, Fabic was first implemented based on Kafka's distributed message service.

  In the Fabric network, an enterprise can have one or more nodes join the entire alliance chain; an enterprise can join 1 or more Channels (subnets); a node can join 1 or more channels. Each channel forms a subnet, so Fabric is a network composed of subnets.

So how does Fabric implement the execution of smart contracts and complete business uploading (recording transaction results in the blockchain)?

Unlike other frameworks, Fabric divides the entire process into three stages:

Business endorsement stage: The endorsement node sent by the customer's request completes the business calculation through smart contracts (but does not update the status), and completes the endorsement; returns the endorsement result to the client.

Business sorting phase: The client sends the endorsement results to the ordering node (orderer) through the Channel. The ordering node completes the sorting of transactions, packages them into blocks, and finally distributes them to all connected The node of the channel.

Business verification and writing to the ledger stage: Through the Gossip network, all Channel nodes will receive the new block. The nodes will verify each transaction in the block to determine whether it is valid: valid will be followed by In the new world state, invalid ones will be marked as "invalid" and the world state will not be updated, but the entire block will be completely added to the ledger (including invalid transactions).

Based on the above description, Fabric nodes can actually be divided into , ordinary nodes and Order nodes:

Peer, ordinary nodes, complete endorsement (including execution of contracts only) and Verification.

orderer, sorting node, completes sorting.

The Fabric network that joins the orderer node can be described as follows:

Each Channel defines all nodes belonging to the channel, but it is not necessary that all nodes are connected to the Orderer Nodes (private data or transactions can be spread between nodes through gossip protocol communication).

In the blockchain, consensus is the basis of the blockchain.Different from the public chain, the consensus of the alliance chain requires that all transactions added to the ledger are deterministic and final, that is, there cannot be forks, the order between blocks is certain, and there is only one chain. In Fabric, this objective requirement is realized by sorting. All transactions will be submitted to the orderer node to obtain a determined order, and finally packaged into blocks and entered into the ledger. Fabric supports the implementation of ordering services based on Raft starting from 1.4.1, which can be considered as the implementation of consensus based on Raft.

The RAFT-based sorting service has better distribution and simpler configuration than the early Kafka. It is a commonly used consensus algorithm in alliance chains. Quorum uses RAFT as the consensus by default. layer. Simply put, RAFT is a leader and follower model. All nodes joining the RAFT network have a leader at any time. Only this leader has the right to decide the order of transactions and package them into blocks. Other nodes can only submit transactions as followers. and sync block.

Based on the FAFT network, each enterprise can have one or more nodes participating in the Orderer. In Frabric, the network connection between enterprises can be changed into the following form:

Users of blockchain are called EOA (External of Account) in Ethereum, and the carrier of EOA is a wallet. Let's use this concept to see how Fabric implements users and initiates transactions. EOA in Fabric is a certificate (x.509) issued by the CA center. A Certificate represents an Identity (this is still very different from Ethereum. An EOA in Ethereum is actually a hash address). Channels that EOA can participate in And the authorized operations are determined by the MSP (Membership Service Provider) of the channel (as shown below).

Note: Certificate is a common method of verifying identity in cryptography; certificate contains personal information, public key and signature of the CA that issued the certificate. The verifier only needs to have the CA's certificate (including the CA's public key) to verify whether the signature is correct and whether the content of the certificate has been tampered with. Simply put, through CA and Certificate, we can obtain a verifiable identity and trust chain.

As shown in the picture above, fabric Zhongtong uses Wallet as the carrier of EOA. A Wallet can contain multiple Identities (x.509 certificate). Identity verifies correctness through the chain of trust provided by the CA.

After verifying the identity, Fabric uses MSP to resolve in the blockchain network whether the identity represents a member of the organization and what role it has within the organization. For example, the channel will first verify whether the current user Identity is a valid identity, then check the enterprise and role it has through MSP, and finally determine whether the user has the right to perform operations.

It can be said that Fabric access control is completed through MSP. An MSP needs to be defined every time access control is required. For example, each channel defines an MSP, which specifies the access rights to resources within the channel range. MSP is an obscure concept in Fabric, and it is also the basis for providing secure access between enterprises.

As mentioned earlier, Fabric divides business processing and Internet access into three parts: endorsement, sorting, and adding to the ledger after verification.

Endorsement is the stage in which Fabric executes smart contracts. In Ethereum, smart contracts are executed in the EVM and are supported in multiple languages. In Fabric, smart contracts are called chaincode: A chaincode can be understood as a container of smart contracts, which can contain one or more smart contracts. It is not used in EVM. Chaincode is executed in JVM or NodeJS.

Client applications access the ledger through smart contracts. Each accessible smart contract is installed on a node accessible to the client and is defined in the channel. (Nodes with smart contracts are called endorsement nodes, nodes without smart contracts are called unsubmitted nodes, and submitting nodes only maintain ledgers)

The client application submits a transaction request, and the request reaches the endorsement node , the endorsement node will first verify the customer's signature to ensure that the customer's identity has the right to execute this transaction, then execute the smart contract (chaincode) mentioned in the transaction, and generate an endorsement response (or transaction proposal, trans-proposal). This endorsement response usually contains the world state's read set, write set, and the node's signature for this transaction. here withThe main difference between the Ethereum-based alliance chains is that the endorsement phase only simulates transactions and does not actually update the transaction results. The real update transaction is completed in the third phase. The endorsement node finally sends the generated endorsement response fanhui to the client, and the execution of the smart contract part ends.

Usually the execution of a transaction requires the signatures of multiple parties, so the client needs to send a transaction to multiple endorsement nodes, and the selection of these endorsement nodes needs to meet the requirements of the endorsement policy.

The following figure is a network diagram including customers, endorsement nodes, and submission nodes.

According to Fabric’s official reference document, the process of successful customer transactions can be described in the following figure.

As shown in the figure above, from 1 to 3, it is the endorsement stage, 4 is the sorting stage, and 4.1, 4, 2, 5 are the verification and submission stages. Refer to Frabic's node concept to learn more about the concept of transaction details.

Generally speaking, Fabric is more focused on inter-enterprise. Through the above, everyone can have a general understanding of the basic composition and concepts of Fabric. Fabric itself is not mysterious. It uses existing inter-enterprise technologies. For a better understanding, it is recommended to read Support for Distributed Messaging Systems and Enterprise Security Infrastructure (CA related). Compared with the Ethereum-based alliance chain implementation, Fabric's subnet concept is more adaptable to complex inter-enterprise applications, but its complex security considerations make operating costs very high. In addition, Fabric uses Certificate as user identity, which has great The limitations of Fabric will be changed in the new 2.0.

In the next article, we will take a look at Sawtooth, a blockchain framework provided by Inter.

Blockchain Alliance Chain (1) Understanding Ethereum

Blockchain Alliance Chain (2) Understanding Quotum

Blockchain Alliance Chain of Blockchain (3) Understanding Fabric

Alliance Chain of Blockchain (4) Understanding Sawtooth

D. Which company is best for blockchain application development

< p>Blockchain technology was announced through a 2008 paper titled “Bitcoin: A Peer-to-Peer Electronic Cash System” written by Satoshi Nakamoto. Interestingly, this article does not specifically use the word “blockchain”.

This article discusses a "pure version of electronic cash" in which "the network works by hashing transactions into persistentA hash-based proof-of-work chain is used to mark the time of a transaction, creating a record of "work" that can be changed without redoing the proof.

The open source PT-BSC (Blockchain Security Control) defines blockchains as peer-to-peer networks that record time by hashing them into an ongoing hash-based proof-of-work chain Stamps, which form records that cannot become records, are changed without redoing proof of work. Blockchain can be permissioned, permissionless or hybrid.

A distributed ledger, on the other hand, is defined as a peer-to-peer network that uses a defined consensus mechanism to prevent modification of an ordered sequence of timestamped records. Consensus mechanisms include proof of interest, joint Byzantine agreement, etc.

The most popular blockchain platform

1. Ethereum
Ethereum is an open source Blockchain platform that runs smart contracts and provides programming tools for their creation . After being proposed by Vitalik Buterin in 2013, the platform simplifies the development of next-generation decentralized applications (DApps) and online contract protocols.

Ethereum allows the design and issuance of cryptocurrencies and tradable digital tokens. What's more, you can create your own DAO (Democratic Autonomous Organization), for example, a virtual organization that solves various problems through member voting.

The platform offers many useful features, including a Turing complete language, command line tools (built in Go, C++, Python, Java, etc.), and an Ethereum wallet, which is the last one that supports and Protect crypto assets and simplify smart contract development for developers.

2. BigChainDB
BigChainDB is an open source distributed ledger system designed to store large amounts of data and enable developers to deploy blockchain proof-of-concepts and applications.

The database provides decentralized control, low latency, immutability, powerful query capabilities, and high-speed transaction processing.

The system does not have its own currency but allows the issuance and transfer of any assets, tokens and cryptocurrencies. BigChainDB supports customizing digital assets and establishing access permissions at the transaction level.

BigChainDB is based on the federated consensus model, an alliance of nodes with voting rights. BigChainDB supports public and private networks and has many use cases, including areas such as intellectual property, human resources, government and land registration.

Also, get an in-depth look at how Bitcoin, Ethereum, and BigchainDB compare.

3.Blockchain Hyperledger Fabric
Blockchain Hyperledger FabricIt is one of the most popular Hyperledger projects hosted by The Linux Foundation and released in 2016. Hyperledger Fabric is written in Go and uses Docker containers to implement smart contracts.

The platform is the basis for building blockchain-based solutions based on a modular architecture and supports the use of one or more networks. To ensure high levels of flexibility, reliability and scalability, Hyperledger Fabric is best suited for developing enterprise solutions.

Considering useful features, it includes channels for sharing confidential information and transaction endorsement policies. Additionally, the transaction includes the signatures of all signing peers and is submitted to the ordering service. Hyperledger Fabric is one of the best platforms for creating permissioned blockchains.

4.Hyperledger Cello
Hyperledger Cello is a blockchain platform and operating system and one of the Hyperledger projects hosted by the Linux Foundation. Hyperledger Cello aims to minimize the effort of designing and managing blockchains by providing an on-demand "as-a-service" deployment model to the Blockchain ecosystem.

Hyperledger Cello enables developers to create a Blockchain-as-a-Service (BaaS) platform from scratch and manage the blockchain lifecycle. What's more, with Cello, they can maintain a set of networks on top of bare metal, virtual clouds, and container clusters (Cello supports Docker, Swarm, and Kubernetes).

5. Hyperledger Sawtooth Lake
Hyperledger Sawtooth Lake is a blockchain platform that represents enterprise solutions that support permissioned and permissionless development. The platform helps software engineers create, deploy and run distributed ledger systems and applications more easily.

Sawtooth Lake is a modular suite written in Python that provides smart contract abstractions, allowing developers to write contract logic in their desired programming language. Transaction business logic in Hyperledger Sawtooth is separated from the consensus layer.

The consensus mechanism is called Proof of Elapsed Time (PoET) and uses the SGX Trusted Computing Module built into the latest generation of Intel processors.

There are many useful applications for Sawtooth Lake. For example, in supply chain management and seafood distribution, it can solve problems such as improper food storage conditions, illegal fishing practices and seafood fraud.

In addition, HyperledgerSawtooth ensures a secure infrastructure for the creation and exchange of digital assets. Learn how Sawtooth Lake and its solutions work in different areas.

6. Hydrachain
HydraChain is an open source extension of the Ethereum Blockchain platform that provides support for the development and deployment of permissioned distributed ledgers.

HydraChain is fully compatible with the Ethereum protocol and provides an infrastructure to create smart contracts in Python. Hydrachain has many tools to shorten development time and improve debugging capabilities.

Importantly, HydraChain ensures a high level of customization: every aspect of the system can be easily configured to meet the customer's needs. For example, things like transaction fees, gas limits, genesis allocations, and block times can be easily customized when creating a smart contract.

7. Corda
Corda is an open source Blockchain platform for building permissioned distributed ledger systems. Created by the R3 Alliance, the project combines large banks and allows the management of legal agreements between parties.

Like other distributed ledgers, R3 Corda provides secure data storage and immutable data records. Notably, only Corda can develop interoperating blockchain networks that conduct transactions with strict privacy. Currently, it may be the only distributed ledger platform with pluggable consensus.

8. Multichain
Multichain is an open source distributed ledger system based on the Bitcoin blockchain and designed for processing multi-currency financial transactions.

The platform provides various levels of access control and permissions and enables rapid solution deployment. In Multichain, various networks can be on one server at the same time.

9. Open Chain
As an open source blockchain platform, Openchain is designed for the issuance and management of digital assets in a powerful, secure and scalable way. The technology includes smart contract modules, a unified API, and multiple levels of control and access thanks to a hierarchical account system.

In Openchain, every transaction is digitally signed (just like Bitcoin), and the consensus mechanism is introduced by branch consensus. You should note that Openchain is free, so you don’t need to spend cryptocurrency to use it.

10. Chain Core
Chain Core is an enterprise-grade blockchain platform designed by Chain Protocol and Link Protocol for publishing, transmitting andManage digital assets. Additionally, the platform enables developers to create financial services from scratch.

In the core of the chain, local digital assets involve currencies, securities, derivatives, gift cards and loyalty points. The platform provides role-based permission access management to operate within the network. Chain Core features federated consensus and provides smart contract support, transaction privacy, and multi-signature account support.

E. Blockchain Graduation Project Proposal

Background of the project research:

With the development of modern technology and information industry, at this stage, the The Fourth Industrial Revolution has begun to take shape, and the world is about to enter a technological era centered on new technologies such as the Internet and artificial intelligence. At the same time, blockchain technology has emerged as the times require and has become a hot topic of concern to many international governments and industries. Blockchain technology has been regarded as the core technology with the greatest potential to trigger the fifth round of disruptive revolution after steam engines, electricity, information and Internet technology. In the past 10 years, with the strong support of the government and policies, the development situation of my country's philanthropy has been relatively optimistic. However, as the scale of charity continues to develop and expand, my country's public welfare undertakings have gradually revealed some shortcomings. The biggest problems existing in traditional public welfare undertakings are insufficient credibility, imperfect internal management of charitable organizations, and high costs. However, many Internet public welfare service companies are currently actively using the new technology of blockchain to solve this problem. Blockchain technology has the characteristics of decentralization, information traceability and non-tampering, openness and transparency, and smart contracts. It can make up for the shortcomings of traditional public welfare undertakings such as opaque information and low management efficiency. Blockchain technology will enter public welfare undertakings and will Bring new development opportunities to the charity industry.

The main content of the research: This topic mainly includes the following three aspects:

[if !supportLists] 1. [endif] Combination of blockchain technology and public welfare Problems that arise and solved.

[if !supportLists] 2. [endif] Make a public welfare query webpage based on blockchain technology

[if !supportLists] 3. [endif] The query system Application issues and explanations

Purpose of the research:

As the scale of my country’s public welfare continues to develop and expand, our shortcomings have also been exposed, including lack of credibility, and charitable organizations There is a lack of management, and the use of blockchain technology can solve this problem. This technology will track and store data and behaviors throughout the donation process, realize the complete disclosure of the public welfare chain, enable donors to effectively supervise, avoid shortcomings such as low efficiency and clear fund flows, control risks for public welfare projects, and improve Credibility and transparency of public welfare projects promote the development and progress of public welfare projects and enhanceTrust between people. According to the attributes and characteristics of the blockchain system, public welfare enterprises can implement full-cycle tracking, evidence storage and auditing of data and behaviors in the public welfare process, so that all parties involved in public welfare projects can conduct full-process tracking and effective supervision of the project, avoiding Due to the shortcomings of artificially reducing efficiency in public welfare, it provides a rational method for public welfare projects to control risks and judge effects, improve the transparency of public welfare undertakings, and promote the development of public welfare.

Significance of the project research: This project intends to develop an open and transparent system for tracking public welfare donations based on blockchain technology and combined with the actual development of public welfare undertakings in my country. Through in-depth analysis of blockchain technology and charity business, we found that blockchain technology has natural advantages in solving the problem of public welfare transparency. Blockchain technology can be understood as a distributed accounting method that can record all transaction information and ensure that it cannot be tampered with. This determines that wherever justice, fairness, and integrity are required, blockchain has great technology. Room to play. At the same time, the addition of smart contracts directly solves the business problem of earmarked funds.

Eventually, trust between citizens will be enhanced, donation channels will be accelerated, and the development of social donations will be promoted

2. Literature review (current status and development of relevant research at home and abroad Trend)

[if !supportLists] (1) [endif] Current status of foreign blockchain-related industries

China and Europe are gradually occupying the world in blockchain industry policies, and the EU is The European Blockchain Observation Forum has been established in February 2018. Its main responsibilities include: policy determination, industry-university-research linkage, cross-border BaaS

(Blockchain as a Service) service construction, standard open source formulation, etc. Investing 5 million euros in Horizon2020 as a blockchain research and development fund (before December 19, 2018), it is expected that investment in blockchain will reach 340 million euros within three years (2018-2020). In the United States, due to different policies among states, although blockchain is still a craze among American start-ups, the promotion of industrial policy has been slow. The Middle East, led by Di Pai, is leading the trend of blockchain. The government is taking the lead and enterprises are cooperating to explore new technology applications of blockchain. Japan and South Korea are also relatively active in the Asia-Pacific region. Japan is dominated by NTT and the government provides support. South Korea uses finance as an entry point to explore blockchain applications. Isism is also a constant threat to all areas of Chinese society. A comprehensive review of the development status of new media culture in major foreign developed countries, summarizing experiences, and drawing lessons have certain implications for the development of new media culture in China.

[if !supportLists] (2) [endif] Current status of domestic new media research

The State Council of China issued the "Thirteenth Five-Year Plan for National Informatization", and new technologies such as blockchain, big data, artificial intelligence, and machine deep learning have become a national layout focus. The People's Bank of China issued the "Thirteenth Five-Year Plan for the Development of Information Technology in China's Financial Industry", which clearly proposed to actively promote research on the application of new technologies such as blockchain and artificial intelligence, and organize pilot projects for national digital currency. In October 2017, the Ministry of Industry and Information Technology released the "White Paper on China's Blockchain Technology and Application Development", which is the first official guidance document for blockchain.

Governments across the country, especially in coastal areas, have established blockchain experimental sites and research institutes. At present, the governments of Shenzhen, Hangzhou, Guangzhou, Guiyang and other places are actively establishing blockchain development zones and providing special support policies. China Guangzhou officially released 10 Guangzhou blockchain strategies in December 2017 to create a blockchain enterprise technology innovation zone in Huangpu District and Development Zone. In March 2018, the Shenzhen Municipal Economic, Trade and Information Commission issued the "Notice of the Municipal Economic, Trade and Information Commission on Organizing and Implementing the Second Batch of Support Plan for the New Generation Information Technology and Information Security Transformation of Shenzhen's Strategic Emerging Industries in 2018". The district Blockchain is on the list of support directions. This is the fifth local government in China to introduce support policies for blockchain after Guangzhou, Guiyang, and Gehangzhou.

(3) Current status of blockchain in the open source field

Hyperledger (Hyperledger)

Hyperledger (Hyperledger) is developed by the Linux Foundation The open source project to promote blockchain digital technology and transaction verification, launched in 2015, has attracted the participation of many companies including IBM, Intel, Fujitsu, UPS, Cisco, Huawei, Redhat, Oracle, Samsung, Tencent Cloud, Internet Finance, etc. Currently, There are already more than 200 member units, and Bran Behlendorf, founder of the Aache Foundation, serves as the executive director of the ledger project.

The goal of the Hyperledger project is to allow members to work together to build an open platform to meet user cases from many different industries and simplify business processes. Process Ledger has multiple blockchain platform projects, including the Fabric project contributed by BIM, the Sawtooth project contributed by Intel, and Iroha, Burrow, Indy, etc.

The development status of blockchain in the field of standards

ITU-T

ITU-T (International Telecommunication Union Standardization Organization) in 2016By the beginning of 2017, SG16 (Study Group), SG17 and SG20 respectively launched research on the overall needs and security of distributed ledgers to attract applications in the Internet of Things. Established three focus groups (Focus Group on Distributed Ledger (FG DLT), Focus Group on Data Processing and Management (FG DPM), and Focus Group on Fiat Digital Currency (FG DFC)), focusing on blockchain and distributed ledger respectively. Technology application and service research, establishing a trustworthy Internet of Things and smart city data management framework based on blockchain, and carrying out standardization work on blockchain applications based on digital currency. Huawei serves as the chairman of the Architecture Group of the Focus Group on Distributed Ledger (FG DLT) and the Blockchain Group of the Focus Group on Data Processing and Management (FGDPM).

Two committees of CCSA (China Communications Standards Association) have established subgroups and projects respectively:

CCSA TC10 (Internet of Things Technical Working Committee) Established in October 2017, the Internet of Things Blockchain Subgroup: Responsible for the application research and standardization of blockchain technology in the Internet of Things and its covered areas such as smart cities, Internet of Vehicles, edge computing, Internet of Things big data, Internet of Things industry applications, logistics and intelligent manufacturing, and is led by China China Unicom technical experts serve as team leaders, and Huawei technical experts serve as deputy team leaders.

The Blockchain and Big Data Working Group under CCSA TC1 (Internet and Application Technology Working Committee) completed two blockchain industry standards: "Blockchain: Part 1 Overall Technical Requirements for Blockchain ” and “Blockchain: Part 2 Evaluation Indicators and Evaluation Methods”, in which Huawei actively participated.

JPEG

During the 78th JPEG Conference in February 2018, the JPEG Committee organized a special session on blockchain and distributed ledger technology and their impact on the JPEG standard. Meeting. Taking into account the potential impact of technologies such as blockchain and distributed ledgers on future multimedia, the committee decided to establish an ad hoc group to explore use cases and standardization needs related to blockchain technology in a multimedia environment, with a focus on imaging and multimedia applications. standardization work.

IETF

The "Decentralized Internet Infrastructure ProposedRG

(Research Group) was established at the IETF99 meeting in June 2017, planning to study the blockchain architecture. and corresponding standards. In 2018, IETF will likely pay more attention to the implementation and development of blockchain interconnection standards on the blockchain.



3. The proposed research methods (plans, technical routes, etc.) and feasibility demonstration

This topic mainly studies the application of blockchain technology to charitable donations. The research methods adopted:< br />
1. Use the literature method to collect relevant theories, use information retrieval, screening and other methods to collect literature materials and related theories, understand the current situation of blockchain technology, and master the blockchain decentralization technology.

2. Combine the technology with public welfare by combining theory and practice. Complete improvements to the system.

3. Use the method of comparative analysis to discuss the current development status of new media operations from both domestic and foreign aspects, as well as existing problems in the development of my country's new media operation models, and look forward to the development prospects of this technology field.

Feasibility demonstration:

1. Technical feasibility. The research goals involved in this topic already have considerable theoretical foundations at home and abroad. Through literature survey, we can learn about actual, reliable and useful information data, and the actual requirements are not difficult.

2. Economic feasibility. The research on this topic can be done by accessing literature and materials through the Internet and libraries. It is convenient and feasible and does not require a lot of economic consumption. Therefore, from an economic point of view, it is completely feasible.

3. Operational feasibility. This topic requires the combination of blockchain technology and public welfare, especially the tracing of these applications. A comprehensive analysis of the graduation project system on this topic can be achieved through the analysis of both Study the literature and study the existing information documents, use the data you collected to organize and analyze, apply what you have learned, and complete this project completely. From an operability point of view, it is completely feasible.

4. Expected results (or expected results)

1. Through research on the data, clarify the relevant concepts of blockchain technology, skillfully use dapp, and create a web page.

2. Through distributed applications, creating a system that allows the public to quickly browse and understand the public welfare process will increase convenience for the further development of my country's public welfare undertakings.

3. I hope that I can continue to learn and make progress from the process of writing this paper. Being able to master the relevant knowledge of blockchain will be helpful to your future career.