Mail blockchain

1.

If you want to understand the application of blockchain, you can refer to many books and opinions, such as illustrated blockchain, blockchain: reshaping the economy and the world, blueprint and guide of new economy, and articles of coin'an community, including a detailed understanding of the platform of coin'an community, with great strength

As the name suggests, blockchain is composed of block and chain. It is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and so on. It is a kind of chain data structure that combines data blocks in order according to the time sequence, and it is a secure and reliable distributed account book that can not be tampered with and forged by means of cryptography

in 2008, in his paper bitcoin: a peer-to-peer e-cash system published by Nakamoto, he first proposed the idea of blockchain and encrypted digital currency. Starting from bitcoin, blockchain has become the underlying technology of various digital currencies

Second, the working principle of blockchain:

1. The basic concepts include: (1) transaction: one operation will change the account status once, such as adding a record 2) Block: records the transaction and status data within a specified time, which is a consensus and preservation of the current account status 3) Chain: it is composed of a series of blocks in chronological order, which is the log record of the whole state change. If you understand the working concept of blockchain, it is not difficult to understand its working principle. Suppose there is a distributed data logbook, which can only be added, not deleted or changed. Its structure is a linear chain formed by a series of "blocks" (which is also the source of the name of "blockchain"), and new data must be put into a new block to be added, The maintenance node can propose a new block, but it must go through a certain consensus mechanism to reach an agreement on the final selected block

2. Take bitcoin as an example to see the working principle of blockchain

the block of bitcoin is divided into block head and block body

Core advantages and characteristics of blockchain

1. The verification, accounting, storage, maintenance and transmission of decentralized blockchain data are all based on distributed system structure. There is no centralized hardware or management organization, and the rights and obligations of any node are equal, The data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system. 2. The open and transparent system is open. In addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all. Anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent. 3. Security blockchain uses consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work. 4. Information cannot be tampered with. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% (almost impossible) nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid. Therefore, the data stability and reliability of the blockchain are extremely high. 5. Anonymity because the exchange between nodes follows a fixed algorithm, and its data interaction does not need trust (the program rules in the blockchain will judge whether the activity is effective or not). Therefore, the counterparties do not need to let the counterparties generate their own trust by disclosing their identities, which is very helpful for credit accumulation

At present, the most popular classification of blockchain is to divide blockchain into public blockchain, private blockchain and consortium blockchain according to different participants

1. Public chain: anyone can participate in the use and maintenance, and can obtain the effective confirmation of the blockchain. Public chain is the earliest blockchain and the most widely used blockchain at present, such as bitcoin blockchain. The information is completely public

if the licensing mechanism is introced, it includes private chain and alliance chain. 2. Private chain: a company or indivial only uses the blockchain technology, enjoys the exclusive write permission of the blockchain, and does not disclose the information. At present, conservative giants (traditional finance) want to experiment with private blockchain, and the application procts of private blockchain are still groping. 3. Alliance chain: it is a blockchain between the public chain and the existing chain, which is jointly controlled by multiple organizations. The use of the chain is managed with authority, which can be controlled by the manager, and also open to others according to the manager's wishes. In addition, according to the different use scenarios and purposes of blockchain, it can be divided into currency chain for the purpose of digital currency, property chain for the purpose of recording property rights, and crowdfunding chain for the purpose of crowdfunding

On May 28, Ma Huateng, CEO of Tencent, proposed the anti-counterfeiting method based on cloud integrated blockchain technology, which is far more efficient than traditional anti-counterfeiting methods. The future anti-counterfeiting verification scenario may only require users to use their mobile phones for simple scanning, and a large number of complete information based on different dimensions can be obtained

take Maotai liquor as an example:

distillery address, proction workshop, operation staff, inspector, delivery time, transportation vehicle information and driver information,

liquor year, raw material source, raw material supplier, storage warehouse number, raw material transportation vehicle and driver information,

all information can be accurately traced, permanently recorded and tampered with

the above information can be easily verified

2. Food safety issues as early as last November, Wal Mart has cooperated with IBM to track the source of food by using blockchain technology, so as to ensure the safety of food and increase the circulation of food to rece costs. For Wal Mart and other large supermarkets, it took a few days to investigate the source of problem food, After using this technology, only one item of proct information is needed to achieve accurate traceability, and important information such as food origin, inspector, supplier, logistics and transportation can quickly find problems in a few minutes. Currently, procts tracked by blockchain include packaging procts from the United States and pork from China

3. Information security

blockchain technology is promoting an information security technology revolution. (1) identity protection PKI is a common public key encryption technology in e-mail, message application, website and other communication applications. However, since the implementation of most PKI, the centralized trusted third party certification authority (CA) is used to issue, activate and store user certificates. Hackers can attack PKI to fake user identity or crack encrypted information

certcoin is the first PKI implementation of blockchain, which comes from MIT, removes the centralized authentication center, and uses blockchain as a distributed ledger for domain name and public key

pomcor company: blockchain PKI implementation path: keep the authentication center, and use blockchain to store the hash value of issued and activated certificates. Users can verify the authenticity of certificates through decentralized and transparent sources, and can also improve the network access performance through local authentication of secret key and signature based on blockchain

(2) data integrity protection

guardtime developed a secret key free signature architecture (Ksi) based on blockchain technology to replace the secret key based data authentication technology. Ksi stores the hash table of the original data and files on the blockchain, runs the hash algorithm to verify other copies, and compares the results with the data stored in the blockchain. Any data tampering will be found quickly because the original hash table is stored in millions of nodes

(3) key infrastructure protection

the "Achilles heel" of the Internet, DDoS has entered the TB era, DDoS is still the simplest weapon for hackers to bring down the big target with low cost, DNS service is the primary target for hackers to carry out large-scale destruction, but blockchain technology is expected to fundamentally solve the problem

The distributed storage of

blockchain makes hacker attacks lose focus. Nebulis is developing a distributed DNS system, which uses Ethereum blockchain and interstellar Internet file system (IPFs, the distributed substitute of HTTP) to register and resolve domain names. The biggest weakness of DNS is caching, which makes DDoS attacks possible. It is also the bane of the centralized government's censorship of social networks and manipulation of DNS registration. A highly transparent and distributed DNS system can effectively prevent any entity, including the government, from arbitrarily manipulating records

(1) digital currency: improve the convenience of currency issuance and use, such as bitcoin and Ethernet in foreign countries, and guorenbao in China

from the use of physical transactions, to physical currency and credit currency, and then to the rise of bitcoin network, more and more people are aware of the distributed ledger blockchain technology behind it, and graally apply it in many scenarios other than digital currency

(2) cross border payment and settlement: realize point-to-point transaction, rece intermediate fees

transfer and payment. At present, the most mature application of blockchain technology is payment and transfer. Blockchain technology can avoid complicated systems, save the process of inter-bank reconciliation and review, and accelerate the settlement speed; Virtual currency can rece transaction costs without the intervention of clearing house. Different countries have different clearing proceres. It takes two or three days for a single remittance to arrive, which is inefficient and accounts for a large proportion of funds in transit. No longer through the third party, through the blockchain technology to form point-to-point payment. By eliminating the link of the third-party institutions, we can make full day payment, real-time payment, withdraw cash quickly and rece the hidden cost, which helps to avoid the capital risk. It is timely and convenient

(3) bills and supply chain financial business: rece human intervention, rece costs and operational risks

value transfer between point-to-point, control and verify physical bills or central system; Intermediaries will be eliminated and human intervention reced. With the improvement of efficiency, financing channels are more unblocked, risks are lower, and multiple parties benefit

(4) securities issuance and Trading: realize quasi real-time asset transfer, accelerate the speed of transaction clearing

the application of blockchain technology can make the process of securities trading more concise, transparent and fast, rece the plication of IT system, and improve the efficiency of market operation. For stocks, blockchain can eliminate paper and pen or electronic form records, rece human errors in trading, and improve the transparency and traceability of trading platform. Citigroup and Nasdaq cooperate to promote blockchain applications

(5) customer credit investigation and anti fraud: rece the cost of legal compliance, prevent financial crimes

the customer information and transaction records recorded in the blockchain help banks identify abnormal transactions and effectively prevent fraud. The technical characteristics of blockchain can change the existing credit reference system, and store the data of customers with bad records in the blockchain when the bank concts "know your customer" (KYC)

equity crowdfunding:

2. Blockchain is the biggest trend in the next decade
if you look at the problem with the thinking of 30 years ago, you will think that others are crazy, but in fact you are out of date
the concept of blockchain can be traced back to the end of 2008. In the forum, a mysterious personage named "Nakamoto Tsung" published a paper "bitcoin: a peer-to-peer e-cash system" and proposed the concept of blockchain for the first time
on January 3, 2009, the first block of the blockchain was born, which is called the "Founding block"
almost with the birth of blockchain technology, bitcoin became the first thing to play its role. In the following years, bitcoin graally swept the world. In 2017, its crazy market made blockchain technology known to all
the idea of blockchain first appeared in the famous bitcoin open source project. In the process of its birth and development, bitcoin project draws on the technical achievements from digital currency, cryptography, game theory, distributed system, cybernetics and other fields. It can be said that bitcoin project is good at all. As its core supporting structure, blockchain technology is a remarkable innovation achievement
blockchain is a distributed database system with different nodes, which is an open ledger system<
three characteristics of blockchain
compared with the traditional centralized scheme, blockchain technology mainly has the following three characteristics:
the core idea of blockchain is decentralization
in the blockchain system, the rights and obligations between any node are equal, and all nodes have the ability to vote with computing power, Thus, the result recognized by more than half of the nodes is guaranteed. Even under serious hacker attacks, as long as the number of nodes controlled by hackers does not exceed half of the total number of nodes in the world, the system can still operate normally and the data will not be tampered with
block chain's biggest subversive is the establishment of credit
the collective maintenance of blockchain can rece the cost
in the centralized network system, the maintenance and operation of the system depend on the operation and operation of platforms such as data center, and the cost cannot be omitted. Anyone can participate in the nodes of the blockchain. Each node can verify the correctness of the results of other nodes' records while participating in the records, which improves the maintenance efficiency and reces the cost
in a word, blockchain touches money, trust and power, which are the fundamental basis for human survival< Its development has gone through three stages
1. Brewing period: from 2009 to 2012, bitcoin and its instrial ecology are the main economic forms
2. Embryonic period: from 2012 to 2015, with bitcoin entering the public view, new wallet payment and remittance companies appeared, and blockchain economy spread to the financial field. The underlying technology of blockchain is constantly innovated. Blockchain technology is separated from bitcoin system
3. Development period: in 2016, we began to explore instry applications, and a large number of blockchain start-ups appeared. The popularity of ICO in 2017 has given blockchain unprecedented attention
"blockchain 2.0 era" is coming
the application service layer is the driving force for the sustainable development of blockchain, which is divided into three stages of application: 1.0, 2.0 and 3.0
programmable currency: blockchain 1.0 application
programmable currency is the digital currency represented by bitcoin, but it is not the legal tender of any country or region, and there is no government authority to provide guarantee for it
programmable Finance: blockchain 2.0 application& quot; Smart contract& quot; Using program algorithm to replace the concept of contract execution. This enables blockchain to expand from the original monetary system to the registration and transfer of equity, creditor's rights and property rights, the transaction and execution of securities and financial contracts, and even the financial fields of gambling and anti-counterfeiting
programmable Society: blockchain 3.0 application
blockchain is the core of value Internet, which can confirm, measure and store the property rights of information and bytes representing value in each Internet. It can not only record the transactions of the financial instry, but also record almost anything valuable that can be expressed in the form of code. Its application can be extended to any field with demand, and then to the whole society
at present, the application of blockchain has begun to surpass bitcoin (blockchain 1.0), enter the era of blockchain 1.5, and transition to the financial field (blockchain 2.0)
in the next 3-5 years, blockchain may go beyond the financial field and enter the field of social notarization and intelligence (blockchain 3.0), including identity authentication, notarization, arbitration, audit, domain name, logistics, medical care, mail, visa, voting and other fields. Its application scope will be expanded to the whole society, and blockchain technology is likely to become a new technology& quot; All things are connected& quot; It's the lowest level protocol
at present, blockchain technology has been recognized by the world, and its development has become an inevitable trend. Accompanied by more people's attention, "in the next 30 years, new technologies will be integrated into all aspects of traditional instries, and human society will turn upside down. No matter who you are, no matter where you are, all of us will be a part of this great change."
this is the current situation. Blockchain has given the post-90s an opportunity. However, if you want to control blockchain technology without being affected by negative factors, the most important thing is to have a clear understanding of it, whether it is regulators, researchers, speculators or bystanders
it's time to devote more energy to blockchain technology
in China, the average annual salary of blockchain positions has reached more than 300000, and that of some enterprises has reached more than 1 million. The monthly salary of blockchain instry graates in Beijing, Shanghai and other places has exceeded 20K! If the post-90s seize the bonus of the times, they may become the next Alibaba in the future! If you miss it, you may regret it for ten years.

3. There are six hierarchical structures in the blockchain, which are from bottom to top: data layer, network layer, consensus layer, incentive layer, contract layer and application layer
1. Data layer
the data layer is the lowest layer in the six hierarchies of the blockchain. We can understand the data layer as a database, but for the blockchain, this database is a tamperable and distributed database, which is what we call "distributed ledger"
in the data layer, that is, the "distributed ledger", the data information on the blockchain is stored, and the blockchain structure, asymmetric encryption technology, hash algorithm and other technical means of the block are encapsulated to ensure the security of the data in the case of the whole network being open. The specific method is:
in the blockchain network, nodes use consensus algorithm to maintain the consistency of data layer (that is, the distributed database), and use asymmetric encryption and hash algorithm in cryptography to ensure the non usurpation and traceability of the distributed database
This constitutes the bottom data structure of blockchain technology. However, it is not enough to have a distributed database. We also need to let the data information in the database be shared and exchanged. Next, we will introce the upper layer of the data layer - the network layer
Second, network layer
the network system of blockchain is essentially a P2P (point-to-point) network. Point to point means that there is no need for an intermediate link or centralized server to control the system. All resources and services in the network are distributed in the hands of each node, and the transmission of information is also a direct communication between the two nodes. However, it should be noted that P2P
(peer-to-peer) was not invented by Nakamoto, and the blockchain only integrates this technology
therefore, the network layer of blockchain is actually a particularly powerful point-to-point network system. In this system, each node can not only proce information, but also receive information, just like sending e-mail. You can write your own e-mail, and you can also receive the e-mail sent to you by others
in the blockchain network, nodes need to jointly maintain the blockchain system. Every time a node creates a new block, it needs to notify other nodes in the form of broadcast. After receiving the information, other nodes verify the block, and then create a new block on the basis of the block. In this way, the whole network can jointly maintain and update the general ledger of the blockchain system
however, what rules should the whole network follow to maintain and update the general ledger of the blockchain system? This involves the so-called "laws and regulations" (rules), which we will introce next: the consensus layer
Third, consensus layer
in the world of blockchain, consensus simply means that the whole network should maintain and update the general ledger of blockchain system according to a unified and agreed rule, which is similar to the rule of updating data. It is one of the core technologies of blockchain and the governance mechanism of blockchain community to let highly dispersed nodes reach consensus efficiently in the decentralized blockchain network
at present, the mainstream consensus mechanism algorithms include: proof of work of bitcoin (POW), proof of rights and interests of Ethereum (POS), proof of rights and interests of EOS (dpos), etc
we now introce the data layer, network layer and consensus layer. These three layers ensure that there are data, networks and rules for updating data on the network. However, there is no free lunch in the world. How can nodes actively participate in the maintenance of the blockchain system? Here is the incentive layer, which we will introce next: incentive layer< 4. Incentive layer
incentive layer is the so-called mining mechanism, which can be understood as incentive mechanism: you can get as much reward as you contribute to the blockchain system. With this incentive mechanism, the whole network nodes can be encouraged to participate in the data recording and maintenance on the blockchain
mining mechanism and consensus mechanism are actually the same truth. Consensus mechanism can be understood as the company's general rules and regulations, while mining mechanism can be understood as the reward rules for what you do well in the general rules and regulations
just like the consensus mechanism POW of bitcoin, it stipulates that more work pays more. Whoever can find the correct hash value first can get a certain amount of bitcoin reward
and Ethereum's POS stipulates that the older the holder is, the more likely he or she will be rewarded
it should be noted that the incentive layer is generally only available for the public chain, because the public chain must rely on the nodes of the whole network to jointly maintain data, so there must be a set of incentive mechanism to encourage the nodes of the whole network to participate in the construction and maintenance of the blockchain system, so as to ensure the security and reliability of the blockchain system
the blockchain is safe and reliable, and it is not intelligent enough, right? The contract layer we will introce next can make the blockchain system more intelligent
v. contract layer
Contract layer mainly includes various scripts, codes, algorithm mechanisms and smart contracts, which is the basis of block chain programming. What we call "smart contract" is at the contract level
if the bitcoin system is not intelligent enough, the "smart contract" proposed by Ethereum can meet many application scenarios. The principle of the contract layer is to embed the code into the blockchain system, in this way to realize the smart contract that can be customized. In this way, on the blockchain system, once the terms of the smart contract are triggered, the system can automatically execute commands< Finally, the application layer. The application layer is very simple. As the name suggests, it is a variety of application scenarios and cases of blockchain. What we now call "blockchain +" is the so-called application layer. At present, the blockchain applications that have been implemented are mainly various blockchain applications built on
eth, EOS and other public chains. There are more applications of gambling and games, and the real practical applications have not yet appeared.

4. It is a good choice to invest in the blockchain project of Buka instry, which is developed by local cooperation in Bougainville Island, including five types of core businesses.

5.

The attachment of the complete works of the adventures of the ant kingdom TXT has been uploaded to the network disk, and can be downloaded free of charge by clicking:
< file FSID = 2513958225 "link = / share / link? Shareid = 1658003189 & UK = 203687663" name = "wealth =" 0 "/ >

content preview:
beans and soldiers followed the workers to enter the mushroom plantation. Those dedicated ants are busy in and out of the garden. The beans go directly to the farmland. He can't wait to see these magical plants
unlike beans, the mycelial plants that grow mushrooms are white threads. These white threads intertwined together, like marshmallows, and covered the fields fluffy. Careful observation shows that there are many white balls hanging on the clusters of hyphae. It seems that these are the mushrooms that leaf cutting ants rely on
the little boy crouched down to study the extraordinary features of this plant. Suddenly, a noisy sound of footsteps sounded from behind him, the workers who were responsible for harvesting appeared in the mushroom plantation on time
this group of workers walked into the farmland and carefully picked the mature mushrooms from the mycelium. When they left, they naturally divided into two groups. One of them went straight to the palace. They were the "royal cooks" of queen ant. Every mushroom that queen ant enjoyed was brought to her mouth by them. Because of the Queen's huge body, natural appetite, and the need for daily meals, the workers had to run between the palace and the mushroom garden several times a day

6. The Ant Bully

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