Blockchain free communication

1.

blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

blockchain is an important concept of bitcoin. In essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:

1. The blockchain with the whole network open and without user authorization mechanism is called public chain

2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain

3. All the nodes in the network are in the hands of one organization, which is called private chain

alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain

blockchain features

1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain

2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent

3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention

4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes

5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously

2.

Blockchain is a new application mode of distributed data storage, which is an important concept of bitcoin. At present, there are 35 stocks associated with the blockchain concept in the A-share market, of which 6 blockchain concept listed companies are traded on the Shanghai Stock Exchange, and 29 blockchain concept listed companies are traded on the Shenzhen Stock Exchange

according to the correlation of blockchain, the leading stocks of blockchain concept stocks are most likely to be born from Xinchen technology, luyitong and Sifang Jingchuang

Xinchen Technology: on September 29, 2016, the company said in the interaction that the company is now doing research and development of blockchain technology

Lu Yitong: the company plans to raise 67.9691 million shares of additional shares of RMB 24.57 per share, and the total amount of supporting funds will not exceed RMB 1.670 billion, which will be used to pay the cash consideration of this transaction, construct the block chain ASIC chip instrialization project, artificial intelligence ASIC chip R & D center, chip proct marketing and service network, etc

Sifang Jingchuang: on May 31, 2016, the inaugural meeting and the first general meeting of the financial blockchain cooperation alliance (Shenzhen) was officially held in Shenzhen Wuzhou Hotel, and the company was one of the members of the meeting

3. I don't know when the Internet of things has been deeply related to the blockchain, and it has become more and more intense this year. Whenever the Internet of things is mentioned, blockchain will follow; When it comes to blockchain, we must also bring the Internet of things into the topic. The public can't help but wonder whether the Internet of things rubs the heat of blockchain, or does the blockchain pull the Internet of things hard to block the "bullet"? Now let's explore

the term "Internet of things" is mentioned almost every day in today's life. Some data show that in 2017, there were about 8.4 billion intelligent devices connected to the Internet, such as thermostats, cameras, street lamps and other electronic procts. According to foreign McKinsey & company data, this number may reach 25 billion by 2025, and the scale of the whole economy will reach 6 trillion US dollars

are you dazzled by such a huge number? Although the Internet of things technology has been widely used all over the world, its defects are graally highlighted

according to the traditional mode, the data center (server) of the equipment manufacturer often collects the information of all connected devices, which determines that the server needs to have strong operation and storage capacity. Moreover, with the geometric growth of Internet of things equipment, the cost of server maintenance will also increase greatly, which makes it difficult for small and medium-sized enterprises to maintain

at the same time, in terms of communication compatibility, the global Internet of things platforms are lack of a unified language, which is easy to cause communication obstacles between multiple Internet of things devices. This is e to the obvious fragmentation of the Internet of things instry, whether it is smart home, smart home appliances, robots, smart cars, etc., the networks they connect are fragmented and closed. In addition, the status quo of the Internet of things instry is still full of mountains, and their influence is relatively limited, so it is difficult to reach a unified standard in a short time

based on this, the standard chain team, after accumulating the previous experience from the Internet of things, combined with the characteristics of blockchain, proposed the concept of Internet of things
the above is reprinted by Internet of things media. If there is any infringement, please delete it

4. 1. Blockchain is an anti tampering, shared and traceable distributed ledger technology. Anti tampering lies in that the modification of a single node can only be recognized through the consensus of other nodes; Traceability means that the whole account book of the blockchain can only be written in, not deleted, and all modification records will be left marks on the whole chain; Sharing means that the account book of the whole blockchain is transparent to multiple nodes in the distributed network
hash function in blockchain is the key to anti tampering, and hash algorithm is a one-way cryptographic mechanism to ensure that transaction information is not tampered in blockchain. After receiving a piece of plaintext, hash algorithm will transform it into a short and fixed hash data in an irreversible way. So block association has but is not limited to tamper proof
2. Quantum secure communication is divided into quantum cryptography communication, quantum teleportation and quantum dense coding. It can be divided into classical communication and quantum communication. The former mainly transmits quantum key, while the latter can be used for quantum teleportation and quantum entanglement distribution. When quantum communication is eavesdropped, although the eavesdropper can't get the information, the communication is interrupted, which affects the normal communication. His anti eavesdropping is at the cost of interrupting the communication, so it doesn't seem as good as the legend.. At present, there are still many unsolved problems in quantum communication, such as short transmission distance, relay difficulty and so on
3. In secure communication, technology competition and complementarity are mutual reference and common development. In secure communication, blockchain should belong to network layer, and quantum communication should belong to physical layer. Therefore, there should be no competition result of who will replace who.

5. VAT invoice is also a kind of invoice. Enterprises with the qualification of general VAT taxpayer can apply to the competent state tax department for purchasing VAT invoice and issue it through the anti-counterfeiting tax control system. Enterprises with the qualification of general VAT taxpayer can dect vat by VAT invoice. Special invoice is the abbreviation of "VAT special invoice". An invoice issued for the sale of goods subject to VAT. After the implementation of the Provisional Regulations of the people's Republic of China on value added tax, in order to ensure the implementation of the tax dection system of value-added tax which belongs to extra price tax, it is printed and distributed for the use of enterprises. When taxpayers sell goods or taxable services, they shall issue special VAT invoices to the purchasers, indicating the sales amount and output tax amount respectively. The use of special invoice as dection voucher is limited to the general taxpayers who are both VAT buyers and sellers.

6. One of the characteristics of blockchain is to realize irreversibility through distributed ledger technology, and at the same time, various technologies such as ring signature and zero knowledge proof are used to realize anonymity and privacy protection. Social networks are monopolized by Facebook, instant messaging is monopolized by WhatsApp and other centralized procts. They bring incomparable communication convenience to users, greatly improve the frequency and efficiency of communication between people, and bring convenience to billions of people all over the world

through the blockchain, communication services can organize the operation of communication services without the mode of central enterprise. In the future, blockchain should have a real impact on real life, not just by concept and hype, but by real landing procts. What is really landing procts is procts that can meet the needs of users. If the existing centralized procts can well meet the needs of users, then the decentralized procts will not have enough substitution effect, and can not be truly implemented

the protocol layer of blockchain mainly includes four aspects: network programming, distributed algorithm, encrypted signature and data storage technology
the ability of network programming is the main factor for us to choose a programming language, because distributed algorithm is basically the implementation of business logic and can be achieved in any language. The encryption signature technology is directly and simply used, and the database technology is mainly used. Only the implementation of point-to-point network and concurrent processing is the difficulty of development. Therefore, for those languages with strong network programming ability and simple concurrency processing, people especially prefer them

users get the initial number of tokens for free. Some of its practical use scenarios:
1. Encrypted video chat: multinational users want to have video chat, only when both sides hold a certain number of SKM can they achieve encrypted video chat
2. Large capacity file encrypted transmission: the file transmitted by one user to another user exceeds the size limit, and the sender must hold a certain token to realize encrypted transmission
3. Conversation information saving: conversation records can be saved as long as both parties agree, and both parties need to hold a certain amount of tokens
4. Retransmission reminder: if a user sends a file to another user, but he doesn't want the other user to share it, the user can use a certain token to be notified when the file is retransmitted
5. Secret key unlock file: one user transfers the secret key file to another, and only the other party is allowed to view it. The sending user can use the token to let the other party receive the fragmented file. Only by getting the secret key from the sender can the file be unlocked<

the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system.