Open source blockchain

3.

The strict definition of blockchain refers to the distributed database technology that multiple nodes in peer-to-peer network jointly maintain a continuously growing list ledger constructed by time stamp and orderly record data blocks through consensus mechanism based on cryptography technology. This technical solution allows any number of nodes in the participating system to calculate and record all the information exchange data in the system in a period of time to a data block through cryptography algorithm, and generate the fingerprint of the data block for linking the next data block and checking. All participating nodes in the system jointly determine whether the record is true

blockchain is a technical solution similar to NoSQL (non relational database). It is not a specific technology, and can be implemented through many programming languages and architectures. There are many ways to realize blockchain, including pow (proof of work), POS (proof of stake), dpos (delegate proof of stake), etc

the concept of blockchain was first proposed in the paper "bitcoin: a peer-to-peer electronic cash system" by indivials (or groups) who call themselves Satoshi Nakamoto. Therefore, bitcoin can be regarded as the first application of blockchain in the field of financial payment

< H2 > [popular explanation]

no matter how big the system or how small the website is, there is a database behind it. So who will maintain this database? In general, who is responsible for the operation of the network or system, then who is responsible for the maintenance. If it is wechat database, it must be maintained by Tencent team, and Taobao database is maintained by Alibaba team. We must think that this way is natural, but blockchain technology is not

if we think of the database as a book, for example, Alipay is a typical account book. Any change of data is bookkeeping. We can think of database maintenance as a very simple way of accounting. In the world of blockchain, everyone in the blockchain system has the opportunity to participate in bookkeeping. The system will select the fastest and best bookkeeper in a period of time, maybe within ten seconds or ten minutes. The bookkeeper will record the changes of the database and the account book in a block. We can think of this block as a page. After the system confirms that the records are correct, the system will record the changes of the database and the account book in a block, It will link the fingerprint of the past account book to this paper, and then send this paper to everyone else in the whole system. Then, over and over again, the system will look for the next person with fast and good bookkeeping, and everyone else in the system will get a of the whole ledger. This means that everyone as like as two peas in the system is called Blockchain. It is also called distributed account technology. P>

as like as two peas (computer) have identical accounting books, and everyone has the same rights, they will not collapse e to the loss of contact or downtime of a single person. As like as two peas, the data is transparent and everyone can see what changes are in every account. Its very interesting feature is that the data can't be tampered with. Because the system will automatically compare, it will think that the same number of books with the largest number are real books, and a small number of books with different numbers are false books. In this case, it's meaningless for anyone to tamper with his own account book, because unless you can tamper with most nodes in the whole system. If there are only five or ten nodes in the whole system, it may be easy to do so. However, if there are tens of thousands or even hundreds of thousands of nodes and they are distributed in any corner of the Internet, unless someone can control most computers in the world, it is unlikely to tamper with such a large block chain

< H2 > [elements]

combined with the definition of blockchain, we think that we must have the following four elements to be called public blockchain technology. If we only have the first three elements, we will consider it as private blockchain Technology (private chain)

1, peer-to-peer network (power equivalence, physical point-to-point connection)

2, verifiable data structure (verifiable PKC system, non tampering database)

3, distributed consensus mechanism (Solving Byzantine general problem, solving double payment)

4 Game design of Nash equilibrium (cooperation is the strategy of evolutionary stability)

< H2 > [Characteristics]

combined with the definition of blockchain, blockchain will realize four main characteristics: decentralized, trustless, collective maintenance and reliable database. And the other two will be derived from the four characteristics  Features: open source  Privacy. If a system does not have these characteristics, it can not be regarded as an application based on blockchain technology

Decentralized: there is no centralized hardware or management organization in the whole network. The rights and obligations of any node are equal, and the damage or loss of any node will not affect the operation of the whole system. Therefore, it can also be considered that the blockchain system has excellent robustness

trustworthiness: there is no need to trust each other when participating in the data exchange between each node in the whole system. The operation rules of the whole system are open and transparent, and all data contents are also open. Therefore, within the specified rule range and time range of the system, nodes cannot and cannot cheat other nodes

collective maintenance: the data blocks in the system are maintained by all the nodes with maintenance function in the whole system, and these nodes with maintenance function can be participated by anyone

reliable database: the whole system will enable each participating node to obtain a of the complete database in the form of sub databases. Unless more than 51% of the nodes in the whole system can be controlled at the same time, the modification of the database on a single node is invalid, and the data content on other nodes cannot be affected. Therefore, the more nodes and computing power in the system, the higher the data security in the system

Open Source: since the operation rules of the whole system must be open and transparent, the whole system must be open source for the program

Privacy Protection: since there is no need to trust each other between nodes, there is no need to disclose the identity between nodes, and the privacy of each participating node in the system is protected

4. Part of the code is open source, the core code is not open source
or when it is open source, there is a bug in 10 lines
the development of likelib public chain has the following stages: condensation stage, solid foundation (in the next 1-2 years), improvement of technical design documents, completion of basic mole code development, online main chain, continuous improvement of intelligent contract, multi chain parallel, cross chain consensus and other early functions, improvement of main chain, side face and surrounding ecology, including blockchain browser, light wallet and mobile wallet, Smart contract, virtual machine, compiler, development tools, multi language adaptation, etc. Establish, develop and improve open source community, start and promote more application access
in the integration stage, it will grow steadily (in the next 3-5 years), complete the implantation of more consensus moles, realize the self evolution of network, storage and other moles (support EB level data storage), form a standard technical solution system for docking applications in various instries, and explore a new ecosystem combining blockchain with big data, artificial intelligence and other fields. Form a mature open source community and establish application side chain on a large scale
in the sublimation stage, a technology platform integrating blockchain, big data and artificial intelligence will be established everywhere (in the next five years) to provide comprehensive solutions for the proction and operation needs of instry, agriculture and commerce. Form an open source community with the integration of blockchain, big data and artificial intelligence, and provide a comprehensive value docking and cooperation platform.

5. I just want to say what I know better. One is an open source project based on bitcoin system, called cravecoin, and the other is Ethereum. At the beginning, we chose cravecoin for source code analysis, and wanted to carry out secondary development on top of it. However, because Ethereum is more open and well supports smart contracts, we gave up after analyzing for a while
after entering the research of Ethereum, I wanted to start from the underlying source code at the beginning, but the whole process was rather difficult. After re analyzing our requirements, I felt that we could develop to some extent and meet some needs by using its existing interface, so I translated the comments of the source code, basically understood the role of each mole, and no further modification was needed, After all, Ethereum is also a project that took dozens of big bulls a long time to build.
it is very difficult for us to successfully transform it into what we want in a period of time. The faster, the easier, the better
and there is a very important problem. If Ethereum is changed, it will not be able to connect to its public network and use the second largest amount of computing power in the world. This is a matter of putting the cart before the horse. It seems that the answer is wrong, but the main expression is that if the subject wants to do development, it is enough to carefully analyze a project,
after all, the logic is almost the same. We should learn more about blockchain and pay attention to ATV

6. What can blockchain do? Blockchain, a great technology with the birth of bitcoin, can greatly rece transaction costs and improve efficiency in the financial field, which is enough to make Wall Street excited. However, this is only the tip of the iceberg, and its potential application prospects are very wide, which will subvert all aspects of our lives in the future

blockchain is an important concept of bitcoin. In essence, it is a decentralized database, as well as the underlying technology of bitcoin. One of the most basic characteristics of bitcoin is decentralization. In recent months, financial giants have graally begun to pay attention to the technology of bitcoin, and used it in non monetary fields, such as trading, voting and so on 1) Art instry
artists can use blockchain technology to declare ownership, issue works that can be numbered and limited edition, and can target any type of art in digital form. It even includes a trading market where artists can buy and sell through their websites without any intermediary services
(2) the real estate instry
uses blockchain technology to solve various problems faced by everyone when participating in real estate, including naming process, land registration, agency and so on
(3) the insurance instry
the financial instry has always been the most sensitive to advanced technology. Traditional banking and securities giants have been investing in blockchain venture capital since 2014, with a total global investment of US $1 billion in two years
(4) P2P wallet
personal assets can be traded through this P2P wallet in the future without going through any central organization, such as bitcoin

most blockchains are in their infancy, and most of them are overseas. There are very few good blockchain projects in China, so it is not recommended that any non professionals invest in blockchain projects. If you are very interested in blockchain technology and have technical or financial background, it is suggested to consider starting a business in this area. In terms of protocol system of blockchain, the bottom layer is the underlying technology of blockchain, including the technical protocol of blockchain, as well as some platform routing and basic algorithms; In the middle layer, we need to solve the problems of some application interfaces and the issuance and verification of some certificates, including the services of some instry platforms, big data analysis, etc. This is a rough division, and there should be more detailed division; The top is some applications of blockchain, including financial applications and other applications, Internet of things and so on

Introction to Bubi blockchain

since its establishment, Bubi blockchain has been focusing on the R & D and innovation of blockchain technology and procts, has a number of core technologies, and has made substantial innovation in many aspects, forming a number of core technology achievements, such as: mathematically verifiable distributed consensus technology, fast large-scale ledger access technology, and so on Multi Chain general ledger technology supporting business form expansion, interconnection technology between heterogeneous blockchains, etc. On April 25, "gege integral" introced the integral system into the concept of blockchain, opened up by multiple parties, issued and exchanged integral, and promoted the circulation of integral. All cooperative institutions can jointly participate in transaction verification, account book storage and real-time settlement; The third-party payment platform of the enterprise points issuer makes the points in and out more flexible. Bubi has developed its own basic blockchain service platform, which has been applied in equity, supply chain, credit and other fields. Bubi has been committed to building an open value circulation network with the core of decentralized (polycentric) trust, so that digital assets can flow freely

the simple understanding of blockchain is a technology at the bottom of bitcoin, which is also a point-to-point e-cash system, which can realize point-to-point value express. We should distinguish the concepts of bitcoin, bitcoin blockchain, blockchain and blockchain technology. In the countries with more developed finance in the past, the technology of Finance and block has a long history, and the legislation of digital currency and block chain network is also very important. With the advent of the financial era, large financial institutions are studying blockchain technology. They have their own team and concept technology. Graally, regional banks are also participating in the discussion of digital currency. In addition to the application and support of this technology, blockchain has great influence on enterprises. For larger domestic enterprises, Bubi block is also applied to all kinds of equity In the fields of supply chain and points, domestic financial institutions and enterprises have focused on the value of new instries and developed their own blockchain platforms. Blockchain has instantly become a new domestic innovation instry. Overseas, compared with China, the United States has already obtained 15 blockchain patents at the end of last year. The application of blockchain finance is entering a new stage in an all-round way. Various applications will be more and more in-depth, and the relevant changes will attract more and more attention, which will also form a great new trend

financial institutions have launched blockchain technology into a new era of Internet and big data applications, which has laid a pattern from negative interest rate profit driven innovation to technological innovation. At this time, domestic giants have suggested that the cooperation alliance not only affects the implementation of financial infrastructure, but also is an important means to expand business cooperation. In terms of implementation, the future payment system securities deposit will not only affect the implementation of financial infrastructure, It is inseparable from the financial and settlement system and big data analysis, while the domestic giants join hands and propose a mutually beneficial cooperation mode, which can not only effectively improve operational efficiency, but also rece costs and find new growth points, After the adoption of blockchain technology, whether the company's procts and services can proce a new business model or a cost advantage far lower than that of competitors

what can blockchain do? What about blockchain? Although at present, there is no mature underlying blockchain technology platform solution, technical problems such as capacity scalability, privacy protection, non net settlement and non recourse need to be solved, and large-scale application of blockchain technology also needs to reset it architecture and reengineer business process, these are only technical problems. The real test of blockchain technology rooted and growing in the financial field is the regulatory agencies and financial institutions. Will the inherent "de supervision" and "de centralization" characteristics of blockchain make the market players have no power to drive technological innovation. However, because the blockchain is a technology based on mathematical algorithm, the establishment of trust relationship between all parties does not need the help of intermediaries or authority centers, and the cost of establishing trust relationship is almost zero (on the premise of the establishment of blockchain financial infrastructure and ancillary infrastructure), and the blockchain code is open-source, no geographical restrictions, and the network pattern is distributed and interconnected, It lays a technical foundation for the establishment and development of Inclusive Finance and shared finance in the future, and creates material conditions for the integration and unification of global finance. From this point of view alone, blockchain technology is bound to establish a core position in the future financial development, and rely on and complement each other with finance, and win-win in the future.

7.

Blockchain platforms include Ethereum, Asch and other underlying application development platforms

Ethereum, an open source public blockchain platform with smart contract function, provides decentralized Ethereum virtual machine to process point-to-point contract through its special cryptocurrency ether (ETH)

arch, a decentralized application platform based on side chain technology. Asch is designed to lower the threshold of developers, such as using JavaScript as the application programming language and supporting relational database to store transaction data, which is believed to be very attractive to developers and small and medium-sized enterprises

extended data

in 2008, Nakamoto first proposed the concept of blockchain. In the following years, blockchain has become the core component of electronic currency bitcoin: public account book for all transactions

by using peer-to-peer network and distributed timestamp server, the blockchain database can be managed independently. The blockchain invented for bitcoin makes it the first digital currency to solve the problem of repeated consumption. Bitcoin's design is a source of inspiration for other applications

bitcoin is the absolute mainstream of digital currency, and digital currency is in full bloom. Bitcoin, litecoin, dogecoin, dashcoin are common. In addition to currency application, there are various derivative applications, such as Ethereum, Asch and other underlying application development platforms, as well as NXT, SIA, bitstocks, maidsafe, ripple and other instrial applications

8.

On January 14, 2020, Beijing time, Guangdong Zhongke intelligent blockchain Technology Co., Ltd. successfully held the global open source of the underlying technology of IOT blockchain and the launch conference of the ecosystem service system in Huangpu, Guangzhou. It released the underlying technology platform of IOT blockchain iovblockchain to the whole world, relying on mdpos algorithm and cross chain technology, It has officially become the representative platform of the fourth generation blockchain algorithm technology, and ranked among the top ten blockchain underlying technology platforms in the world. After China Science and Technology Corporation settled in Huangpu, in just two months, the number of patent applications for blockchain technology has reached 11.2% of the number applied by the people's Bank of China, and 1.3% of Alibaba, the world's largest patent application company for blockchain technology. It has become the backbone of Guangzhou Huangpu blockchain instry's successful incubation and participation in global blockchain technology competition. At the press conference, China Science and Technology Corporation, Guangzhou intelligent network automobile demonstration area operation center and Zhenbao Bus Group signed a tripartite agreement on blockchain technology application cooperation, which became another important scene of blockchain technology application in Huangpu District

the technological infrastructure route in the development of blockchain instry is particularly important, including the core content of underlying algorithm ability, open source service ability, ecosystem development ability, instry standardization process and digital chip instry application. After long-term scientific research incubation, China Science and Technology Corporation has completed the open source of the underlying blockchain algorithm and started the ecological service system, and will start the standardization construction of the blockchain of the Internet of vehicles and the design and development of digital chips in 2020. The launch of iovblockchain's open source and ecological services indicates that the underlying technology strength of China's blockchain is changing the global competition pattern of a new generation of information technology. In terms of underlying technology and business ecology, as one of the core technology representatives of blockchain, it leads China's blockchain instry and becomes a Chinese force participating in global competition

the press conference was guided by the instry and Information Bureau of Huangpu District of Guangzhou City and supported by the block chain instry association of Guangzhou City, the block chain alliance of Guangdong, Hong Kong and Macao Dawan District, blockchain 728, Guangdong automotive supplies chamber of Commerce and Internet of vehicles branch. More than 100 representatives from instry organizations and core blockchain enterprises attended the press conference and participated in the technology docking activities

this article comes from the author of auto home, which does not represent the standpoint of auto home

9. 1.
the underlying development of blockchain can't be realized with Java
2.
to do the upper development, you only need to dock according to the given open source interface, and then use the language you are good at to develop what you need
3.
now there are many blockchain system templates, you can go to see what development cases there are