Learn about blockchain data in 3 minutes
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 information of bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block
extended data
most blockchain public chains are limited by scalability. The biggest feature of blockchain technology is decentralization, which requires that all accounts in the network need to deal with the accounting process. Distributed accounting has high security, low misoperation rate, political neutrality and correctness
however, blockchain technology embraces these features at the same time, sacrificing scalability, unable to meet the personalized supervision, and slightly insufficient in protecting data privacy. Moreover, with the increase of the number of ledger, the interaction delay will increase exponentially, that is to say, the more ledger in the blockchain network, the higher the delay
Blockchain is a kind of technology, which solves the core "trust" problem in the market economy and reces the trust cost between strangers to a very low level
there is one crucial thing in the market economy, which is "trust". Without trust, no deal can be established. When you go to LAICHANG to buy vegetables, if you don't believe that the pesticide content in vegetable is up to the standard, you won't trade with that dealer; If you buy a bottle of water in a small shop, the clerk will not sell you the water if he doesn't believe that the money you give is real
the traditional small-scale peasant economy is acquaintance economy, and the transaction scale is limited to people who are familiar with each other nearby. If an acquaintance deceives you, he will lose your social relationship and damage his reputation in the whole circle of acquaintances. We believe that acquaintances are less likely to cheat us than strangers
therefore, once we are beyond the scope of acquaintances, we need to use a high cost to identify whether a stranger will cheat me and how to avoid the risk of being cheated. This situation will hinder the transaction and restrict the transaction
in addition, different races, nationalities, cultures, religious beliefs and so on will naturally have this kind of trust problem
in the market economy, why can there be so many transactions between strangers? Because of the birth of a new mechanism to solve the problem of trust in strangers
so far, the most important mechanism to solve the trust problem is the "trust intermediary" organization and mode
as long as you and strangers trust a third-party organization, the trust problem between you can be solved through this third-party organization
this third-party organization, we call it trust intermediary. Both the government and the bank are trust intermediaries
you can sell the goods you have worked hard to proce to a stranger in exchange for a stack of RMB banknotes. It's because the credit of the note issuing bank and the guarantee of the authority of the government guarantee the currency value and effectiveness of the banknotes. Otherwise, sell things, in exchange for a few ordinary paper, who would like to
in the era of global village and Internet, the people who buy your things may be strangers who will not meet and thousands of miles away. Trust is lower, so Alipay assumes the role of trust intermediation. Buyers first pay the goods to Alipay's account. When they receive the goods, they confirm that they are OK, then they agree to sell the goods to the seller. Taobao and other e-commerce have been booming rapidly in just over ten years
trust intermediary is in a central position in the transaction system. All transactions should solve the trust problem through it
However, the cost of trust intermediary itself is often hugeas a trust intermediary, how much transaction tax does the government charge each year? What is the most profitable instry? Financial services. The annual profits of Alipay's ant suit are over ten billion. p> What does this mean? Both sides of the market actually pay a huge trust cost
if there is any way to cancel or greatly rece the trust cost, the transaction cost of the general public can be reced, and the profits can be greatly increased
so in the Internet era, blockchain technology is on the stage
it allows the trading party to get rid of the intermediary, solve the problem of trust among strangers, and greatly rece the cost of trust
the blockchain can be expanded on a large scale, the data is open and transparent, the data of each client is consistent, and even if some clients are destroyed, the data security will not be affected. These highly reliable technical features can solve the trust problem of strangers with low cost
this technology can be extended to all fields that can be digitized, such as digital currency, payment and clearing, digital bills, proof of rights and interests, credit reference, government services, medical records, etc
in the medium and long term, blockchain will be a revolutionary technology, which will bring about great social changes like the existing Internet, and has great investment value and money making opportunities
in the future, the companies that can combine blockchain with different scenarios to promote applications may be the next group of bat, the next Google, Microsoft and apple
as the first practical application of blockchain technology, bitcoin has been widely accepted and used all over the world. Millions of users and tens of thousands of merchants have accepted the payment of bitcoin as a digital currency, and the exchange value of bitcoin as a currency is growing. Even e to the consensus that the total amount is fixed and the long-term value is bullish, bitcoin has become a hedge asset similar to gold, and the price has skyrocketed
whether it's the introction in the network, the answers given by everyone, or the simple and easy to understand introction, you may not really understand blockchain. It's recommended to read more relevant information to understand its landing application. Cryptofinance focuses on blockchain information
in the future, blockchain will be applied in any field and bring great impact on human life. Blockchain technology is regarded as one of the main protocols of the next generation of value Internet. Blockchain technology will be useful in any field of proction and life that lacks trust. From digital currency to securities and financial contracts, health care, games, artificial intelligence, intelligent contracts, Internet of things, identity authentication, asset trading, e-commerce, social communication, file storage and other fields can be widely used
in the aspect of medical treatment
when the blockchain technology is used to save the personal medical records, there will be the historical data of personal medical treatment, which can be understood as the electronic medical records on the blockchain. In the future, there will be data for medical treatment or health planning, and the real master of this data is the patient himself, not the hospital or a third-party organization. In addition, these data have strong privacy, and the use of blockchain technology also helps to protect the privacy of patients
payment system
compared with the existing traditional payment system, blockchain technology can avoid the complex system, directly between the two sides of the transaction, does not involve intermediary institutions, even if part of the network is paralyzed, it will not affect the operation of the whole system. This method has the characteristics of low price, fast speed, and no intermediate fees
banking
as a digital, secure and anti-interference account, blockchain realizes the core function of Banking: the safe storage and transfer center of value. Some banks with keen sense of smell in the world have begun to actively plan to join the army of blockchain research and application in order to gain the initiative in the fierce competition in the future
identity authentication of blockchain
blockchain has the feature of being accessible to everyone. Everyone can query the block information in any place with network. The high transparency also makes blockchain full of charm. In the future, ID card and account book are basically not needed, because every identity information can be written into the blockchain. When you need to verify the information, you only need to look it up to find it
election
based on the voting transaction on the blockchain, it can be confirmed that no vote has been modified or deleted, and there will be no improper voting
Real Estate
blockchain technology can change the operation mode of the real estate market. It can combine many complex processes and cases that real estate companies usually deal with, speed up the transaction process, rece fraud, and provide more transparent and secure transactions for each participant. Provides a way to achieve paperless and fast trading needs
the probability of various kinds of errors in securities issuance and trading, such as general stocks, is too high, which requires manual correction, thus prolonging the time required for transaction settlement. Through the transaction of distributed ledger, the automation of the whole process can be realized, and the security and efficiency can be improved. The identity and transaction volume of the trading party are recorded on the blockchain in real time, with an open, transparent and traceable system. It is concive to the market maintenance of securities issuers and regulatory authorities, and can rece the occurrence of black box operation and insider trading
in the scenario of relatively closed, multi-party trust problems and carrying value transmission, blockchain has unique technical advantages and also shows unique charm, which has great application imagination space. At the current stage, blockchain is worth exploring in some scenarios.
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data
both eurocrowdfunding and Ethereum use blockchain technology.
each block is filled with transaction records, and the blocks are connected in sequence to form a chain structure, which is the blockchain ledger
blockchain technology divides the data to be stored in the database into different blocks. Taking bitcoin as an example, when miners generate new blocks, they need to calculate the new hash value and random number according to the hash value of the previous block, the new transaction block and the random number. Each block is linked to the back of the previous block through specific information, and connected in chronological order to present a complete set of data. In other words, each block is generated on the basis of the previous block data, which ensures the uniqueness of the blockchain data
each blockchain database is essentially an event chain connected in chronological order, which uses the cryptographic mechanism specified in the protocol for authentication to ensure that it will not be tampered with or forged. With the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry
blockchain technology has three obvious characteristics: openness, security and uniqueness
openness mainly refers to that the stored information in the blockchain is completely open to all participants. This is mainly determined by the point-to-point network storage mode of the blockchain. In the blockchain network, each node can store a of the blockchain, and the uniqueness of the blockchain can ensure that the is exactly the same between different nodes
security mainly refers to that the information stored in the blockchain block is saved after being processed by digital encryption technology, and only the private key holder can decrypt the information to obtain the real information. Other members can only see and verify the integrity and uniqueness of information, but cannot see the real information
uniqueness is mainly e to the fact that the information on the blockchain cannot be tampered with once it is on the chain, so it is unique. Of course, the uniqueness here also includes the uniqueness in space, that is, all nodes have only one version of information, and also includes the uniqueness in time, that is, the historical data cannot be changed. This uniqueness also means that the blockchain maintains the characteristics of a unique main chain in the process of operation, and once other chains appear, it is a bifurcation. The emergence of bifurcation will lead to the plication of blockchain in two different spatial dimensions. Of course, to solve this problem, we need to set reasonable consensus rules to avoid
there is no distinction between mobile and non mobile end in blockchain, and if there is one, it is also a gimmick.
EM is a measure based on typesetting conversion, which defines 1em as the height of capital letters of reference font. For consistency with other metrics, CSS defines 1em as the height of the character box. The size in EM is a decimal or multiple of the reference font size. Therefore, 2em and 200% are the same, and. 75em and 75% represent the same size
you write 2em, which is 200%. Of course, you can't see the effect. If you use 0.2em, you can see the effect.