Definition of IDC blockchain

1.

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

2. The definition of Chongqing jinwowo analysis blockchain technology is as follows:
1. Blockchain is a distributed database (system) placed in a non secure environment
2. The blockchain uses cryptography to ensure that the existing data cannot be tampered with
3, the blockchain uses consensus algorithm to reach consensus on new data
the system with the above three properties is blockchain.

3. In essence, blockchain is a distributed database system with cryptography technology, multi-party participation, common maintenance and continuous growth, also known as distributed shared ledger. Each account page in the shared ledger is a block, and each block is full of transaction records. The blocks are connected closely, forming a chain structure; If you don't understand this area, I suggest you learn the basic knowledge from Xuan, Ling, network and company! At present, there are few people who really understand technology and business. Many people follow suit and learn. They are not clear about the definition of blockchain, so they start to attack the blockchain field. Some of them are learning technology, and some of them choose to invest in the blockchain market

4.

In 2014, Barry Silbert, founder of secondmarket, separated the bitcoin investment fund from the original company and established grayscale investments

in 2015, gray investment company was merged into the newly established digital currency group (DCG). DCG is not only focused on digital currency and blockchain investment, but also an incubator for start-ups. In addition to gray investment company, DCG also has two subsidiaries, namely, genesis, a cryptocurrency OTC broker, coindesk, a blockchain news and information website, and more than 150 other blockchain companies / projects invested

after years of development, gray investment company has become the largest cryptocurrency asset management company in the world, and its cryptocurrency trust scale has reached US $2.58 billion

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extended information:

in 2013, Barry Silbert, the founder, convinced the board of directors of secondmarket company to set up a bitcoin investment fund called bitcoin investment trust, which is the predecessor of gray scale bitcoin trust. It was not until September 2017 that gray investment's bitcoin trust fund began to grow explosively

it has become the largest bitcoin investment trust in the world, with more than 408500 bitcoins, nearly 2% of the total. In addition to bitcoin trust funds, gray investment company also launched BCH, ETH, etc, horizon, LTC, XLM, XRP and Zec trust funds, as well as grayscale digital large capital fund with mainstream currencies. Gray investment company's cryptocurrency trust procts provide convenience for institutional users to purchase cryptocurrency

5. Blockchain refers to a distributed and shareable public account book that can be trusted through consensus mechanism and checked by each participant. However, no centralized single user can control it. It can only be revised according to strict rules and open protocols<

features:
1. Decentralization
in current system design or application development, central server is considered to realize all information exchange and data storage. But in the blockchain, through the construction of distributed architecture and open source protocol, all participants participate in data recording and verification, and then send them to each node through distributed propagation. Even if some nodes are attacked or damaged, the integrity and information update of the whole database will not be affected, which means that each participating node is "self-centered"

2, to trust
in traditional Internet mode, it is through the trusted central node (such as the housing registration system) or the third party channel (such as Alipay) to carry out the matching verification and trust accumulation, so it can not achieve the center of value transfer.

3. Timestamp
blocks are generated by packaging all the information (including data and code) generated in a certain period of time. The index information of the previous block is included in the page capital of each next block, and the chain is formed by end-to-end connection. Therefore, the addition of block (Complete History) and chain (complete verification) forms a time stamp (which can trace the complete history). It stores all the historical data in the system, provides retrieval and search functions for each data, and can trace the origin and verify each data by means of blockchain structure<

4. Asymmetric encryption
blockchain is an asymmetric encryption algorithm through the mathematical consensus mechanism, that is, a "key pair" is used in the process of encryption and decryption, and the two keys in the "key pair" have the characteristics of asymmetry: first, only the other key can be decrypted after one key is encrypted; Second, after one of the keys is public, other people can't work out another key according to the public key.