Multi party records of blockchain
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 cryptographyin 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 blockchain1. 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 participants1. 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 obtainedtake 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 ofblockchain 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 Chinafrom 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 risksvalue 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:
(1) distributed ledger, that is, transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can participate in monitoring the legitimacy of transactions, At the same time, they can testify together
different from traditional distributed storage, the uniqueness of distributed storage of blockchain is mainly reflected in two aspects: one is that each node of blockchain stores complete data according to block chain structure, while traditional distributed storage generally stores data in multiple copies according to certain rules. Second, the storage of each node in the blockchain is independent and has the same status, which relies on the consensus mechanism to ensure the consistency of storage, while the traditional distributed storage generally synchronizes data from the central node to other backup nodes[ 8]
no single node can record the account data separately, so as to avoid the possibility that a single bookkeeper is controlled or bribed to record false accounts. In theory, unless all the nodes are destroyed, the accounts will not be lost, so as to ensure the security of the account data
(2) asymmetric encryption and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted, which can only be accessed under the authorization of the data owner, thus ensuring the data security and personal privacy
(3) consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and achieve a balance between efficiency and security
the consensus mechanism of blockchain has the characteristics of "the minority is subordinate to the majority" and "everyone is equal", in which "the minority is subordinate to the majority" does not completely refer to the number of nodes, but also can be the computing power, the number of shares or other characteristics that can be compared by computers“ "Everyone is equal" means that when the nodes meet the conditions, all nodes have the right to put forward the consensus results first, and then directly recognized by other nodes, and finally may become the final consensus results. Taking bitcoin as an example, the workload proof is adopted. Only when more than 51% of the accounting nodes in the whole network are controlled can a nonexistent record be forged. When there are enough nodes in the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
(4) smart contract, which is based on these trusted and tamperable data, can automatically execute some pre-defined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and reliable, it is easy to carry out automatic claim settlement in some standardized insurance procts
Let's suppose villagers Lao Wang and Xiao Li. Lao Wang borrowed some money from Xiao Li, who wrote it in an IOU signed by both parties. A few days later, Lao Wang denied the existence of borrowing money and claimed that Xiao Li forged the paper. Xiao Li can't argue because he finds it difficult to prove that Lao Wang actually owes him money
in this example, Lao Wang and Xiao Li are two nodes
now assuming the same scenario, there are many pairs of people trading with each other in the village. The only evidence for each pair is the IOU. If one party fails, it will be difficult to do so. Seeing this scene, the village head came up with a solution. He suggested using a common notebook for the whole village to record all the transactions. Due to the high prestige of the village head, the villagers unanimously decided to let the village head keep this important transaction book. Each transaction, the villagers go to the village head's home, let the village head witness and record, each transaction is written into a notebook, and then safely saved. That notebook can be called a database
because this notebook is very important, the village head locked it in the safe. However, there are always some problems. Sometimes, the village head will accidentally sprinkle ink on the paper, making some transaction records illegible. This is called a single point of failure. The thief knows that there is an important notebook in the safe of the village head's house. He tries his best to steal it. This is called hacking
until one day, the village head's son owed others a lot of money, so the village head secretly deleted his son's debt entry. In this way, the village head's son "does not owe money."
when the villagers knew this, they began to question the fairness and authority of the village head. So some people put forward a new idea:
abolish the power of the village head, which is called decentralization. Let all villagers keep a notebook, and the transaction records are copied and distributed, which is called distributed database. Therefore, if there are n people in the village, there are n notebooks, that is, n nodes. Every time there is a trade between any two people, all the people in the village get together and record it in their notebooks. And no one can cover the sky. This is called decentralization
they also decided that they would never delete the mentioned transactions from their notebooks, which is irreversible. For example, Lao Wang borrowed a sum of money from Xiao Li before, but in the twinkling of an eye, he wants to return the money. Then the transaction book will not delete the previous borrowing record, but write a new repayment record, so there are two records
next, let's try to break this rule. What if we bribe Lao Wang to change his notebook? It's not feasible, because the next time the villagers meet, they find that Lao Wang's notebook is different from everyone else's, so the villagers notice that Lao Wang may be engaged in an indescribable transaction, and decide to abolish Lao Wang's transaction record and kick Lao Wang out of the organization
What if you try to bribe all the villagers? It's too expensive
the characteristic of this model is that greedy people need to pay a lot to attack the rules. He will find it more profitable to follow the rules
a smart child in the village suggested that each transaction data be called "block" and linked into a "chain" in chronological order, which is called blockchain
1. Technology empowerment and cross-border cooperation
not only Xiaomi and Tencent, but also iFLYTEK has a developer's festival. IFLYTEK's open platform is open source technology, shared with 450000 entrepreneurs. Every day, 4 billion people use iFLYTEK's open technology, which is technology empowerment and cross-border cooperation. Mr. Liu Zihong is building the "flexible +" platform of Rouyu, which is also a typical example from technology enabling to cross-border cooperation
2. Be yourself and practice internal skills
What are we going to do? We should be ourselves and practice our internal skills. As long as you make the best of what you are good at, you will have "core competitiveness". In the past, it was said that we should make up for our shortcomings. Today, the shortcomings are not important. If everyone makes his own long board, he can make the container higher
when he was young, his parents wanted him to become a writer and painter, but his works were evaluated as "no room for shaping" by his teachers. Later, his chemistry teacher discovered his talent. After training, walach won the title of doctor of chemistry at the age of 22, and finally won the Nobel Prize in chemistry
everyone has his own short board. As long as he finds his best position in life and gives full play to the potential of the long board, he can achieve the most amazing results, which is the "Wallach effect". This is the way to be a person, an enterprise and an investment
let me give you an example. There is an investor in Shenzhen who has invested in the consumer instry for more than ten years. He has invested in Zhou Heiya, Baiguoyuan and Naixue's tea projects. Although he is famous today, more than ten years ago, everyone thought that the things he invested in had no room for imagination, and PE was very low, that is, he opened a shop to do business. But he persisted, and has been doing insight, understanding, and research in this instry to invest in projects. Up to now, he has become the top investor in the field of consumption, and has gained in-depth thinking of the instry. This person is Feng Weidong, the managing partner of Tiantu investment
it needs to be hard to forge iron. If you do it well, everything will follow, facing the heart and blooming in spring. To be good at yourself is the most powerful thing
3. Quality revolution and ingenuity return
why does Japan have such a good consumer service instry? Because Japan's economy has been in a downturn for a long time, and the Japanese market is very small, everyone has the opportunity to stand out and be bought by consumers only when they make their procts the best
some people say that it is a good time to get the bottom of the stock market and the real estate market, but I think it is also a very good time to get the bottom of the life. Chen Biao, a senior journalist, once said that we should not forget why we started just because we have gone too far. In today's adjustment period, we have the opportunity to calm down and think about why we want to start a business? What purpose and effect do I want to achieve? Many people around me are already thinking about this
as an interesting example, since our company was founded nearly three years ago, I have not been able to recruit a particularly good editor, because the first group of editors went to Party A as a brand, and Party A had more money and less work; The second group, because we media has risen, many people have gone to work in US media. Now we media is nothing but chicken feathers, and few people can survive tenaciously; The third group of writers have gone to do blockchain media. In my understanding, many blockchain media are public relations media, but who makes it profitable. Later facts have proved that many of them have been shut down
in the face of a phased downturn today, when everyone is thinking about what I am best at, I think the quality revolution may be based on the return of ingenuity, and each of us should think about what we can do and what we can do well
I believe I can recruit a good editor in chief soon
4. Consensus mechanism, rule first
everyone is talking about blockchain today. I made a documentary about three or four years ago, the group dance of black bees. At that time, I was the only filmmaker of wildlife documentary in China. After shooting, because of its uniqueness, this work also won many awards. I would like to make this point: a bee is an insect, and a group of bees are mammals. The work of bees is unconscious and distributed, but the colony has formed an organic function and brought about the reproction of the population. Later, some people described blockchain as honeycomb thinking, which I very much agree with
from the hunting age to the workshop age, from the instrial age to the information age. Every progress of human society comes from the upgrading of cooperative relationship
blockchain has removed the transaction mode based on "organization" link and established the transaction mode based on "person" link. Blockchain technology + Tongzheng economy + community = instrial community. Instry + blockchain, based on the public account book, can make the information symmetry, trust symmetry, resource allocation, cost-effective management, and efficient capital flow of all cooperative entities in the instrial ecology, optimize the proction relations, and fully release the proctivity of workers
5. All things accelerate their evolution, and the only constant is change
why was I the only one who made wildlife documentary at that time? Because it doesn't make money, the price of this film is about 1 million yuan. I shot it for 700 days. After shooting, the company won a lot of awards, but it soon went bankrupt. Today, when I was making a commercial documentary, I didn't dare to do it with such a rhythm
some time ago, we photographed the short rent of piglets. They don't start a business for a long time. When they start a business, their benchmarking is airbnb; At the end of last year, his target was the hotel; Last week, when we went there to visit students, he said that we should do instrial Internet, from information flow to service flow
in this era, the only constant is change. There was a joke in the past that "the only constant for women is fickleness". In fact, in this era, I think the ability to deal with complex situations is one of the most important core competitiveness of founders. Change is to seek death, change is to wait for death. The person who chooses to seek death between seeking death and waiting for death must be an entrepreneur
Bill Gates once said: people always overestimate the changes in the next year and underestimate the changes in the next 10 years. Chen Chunhua once said: in the future, enterprises will only focus on growth rather than success, regardless of size. Xiaomi's Liu De also said: do a good job in this year and arrange for next year. I didn't expect to fall like this when I rang the bell. Zhang Liaoyuan of three squirrels also felt deeply about this: I don't set any goals now. I used to like setting goals, but today I only dare to set goals for next month
every year "I have guests" interviews 500 guests to learn about their cases. We have made nearly 100 programs, reaching 350 million high-end people. The theme of this season is "I have guests - the story of the reformer.". The story of death and posterity is particularly moving. Companies that have never been able to survive are not able to have the motive force of free growth
on the other hand, the guest university does not have the physical wall, nor the shackles of thinking. It has global pattern, seeking change and following reality, opening up knowledge, linking value, dynamic cognition and elite dialogue
it's very meaningful for us and students to go into each company and explore their ups and downs, to feel their changes, their ability to cope with changes, their ability to deal with crises, and to feel life and death with them
Jobs said that he was willing to exchange his life's wealth for the opportunity to talk with Socrates. That is to say, we are going to meet Socrates one by one. We are going to talk with Mr. Fang Hongbo of Midea about how they are going to upgrade from a home appliance benchmarking enterprise to an intelligent instry; Talk to Cai Xiaodong of aofei about how they have changed from a toy factory to an entertainment IP magnate; Talk with Uncle Kai about how they have become the first brand of children's ecation from audio programs; Talk with Mao Daqing about how real estate turns to entrepreneurial services; He also talked with Jiang Xipei of Far East Group about his four survival changes
6, the city is a super instrial community
instrial community is not only the development path that enterprises should take the initiative to explore, but also the development direction of the city. The concept of city that I know is not necessarily a city, but also a district, a small town or a province. Of course, given the concept of "smart city", the instrial community can do better
a benchmark is Shenzhen, where we live today. In 2017, about 70% of the intelligent hardware in China came from Shenzhen. Shenzhen has all the resources and conditions from hardware design to procts. A hardware entrepreneur from Silicon Valley yelled, "here we can find any raw material we want within one kilometer, which is impossible in the United States, Europe and anywhere in the world, because there is no Huaqiangbei in Shenzhen."
Shenzhen provides a very natural convenience for entrepreneurs. There are many great enterprises in Shenzhen, such as Huawei, oppo and youbiexuan. They are all brought up by the fertile land of Shenzhen. There are two kinds of entrepreneurs, Tianpai and Dipai. Tianpai is an Internet entrepreneur; Di Pai is more early entrepreneurs in Shenzhen. They open factories, have their own proction lines, and do things in a down-to-earth way
lack of instrial landing coordination, Internet, app and innovation are "castles in the air"; Lack of technological innovation and upgrading, "local entrepreneurship" will always be the labor force at the end of the instrial chain
only the combination of heaven and earth can we innovate and upgrade and create a better life for us& quot;
blockchain is the big ledger of bitcoin network, and each block is equivalent to a page in the ledger. What information is recorded in the "account book"? At present, each block of bitcoin mainly records data such as block head, transaction details, transaction counter and block size
"block header" contains all information except transaction information, mainly including the hash value of the previous block header, which is used to ensure that blocks are connected in sequence; Time stamp: record the generation time of the block; Random number: that is, the answer to the arithmetic problem of PK for all miners in the whole network; Difficulty target: score the difficulty coefficient of the arithmetic problem
"transaction details" records in detail the transferor, income party, amount and digital signature of the transferor of each transaction, which is the main content of each block
"transaction counter" describes the number of transactions contained in each block
"block size" refers to the size of each block data. Currently, each block is limited to 1MB, which does not rule out the possibility of expansion in the future.
in the future, jinwowo will focus on blockchain technology to promote the legal circulation and commercial application of big data.