Village head account block chain

1. That's a good question. Let me give you an example. For example, when I deposit 100 yuan in the bank, the data of this deposit is only recorded in the bank's database, which can't be obtained by others, namely "central bookkeeping". The blockchain is a distributed accounting, a new information recording technology, and it is "encrypted" and "distributed". The data does not exist in a center, but is stored once on the computer of the whole network. For example, if I transfer 100 yuan to you, I will shout to all the computers in the whole network. Let's record the accounts together, that is, "Distributed Accounting".

2. Blockchain is characterized by decentralization, trust, collective maintenance and reliable database

for example, Sunzi asked Li Zi to borrow 100 yuan, but Li Zi was afraid that he would default, so he asked the village head to do notarization and add the account. This is called centralization. But if you don't ask the head of the village, you can shout "I'll lend my grandson 100 yuan! Please put it in the account book. "This is called decentralization. In the past, the village head was highly respected and had a good command of the accounts of the whole village. Everyone kept their money with him. This was the past trust in centralization. Now, everyone is worried that the village head will secretly misappropriate everyone's money. What should we do? So everyone sent an account book to everyone. Anyone who transfers money between them releases information through the loudspeaker. After receiving the information, everyone records the transaction in their own account book. This is called decentralization. With distributed ledgers, it doesn't matter if Lao Zhang or Lao Li's ledgers are lost, because Lao Zhao, Lao Ma and other families have ledgers

digital currency is abbreviation of digital currency. It is an alternative currency in the form of electronic currency. Both digital gold coin and cryptocurrency belong to digiccy. Blockchain technology service upgrade technology

3. The information of each block in the blockchain is different, and the generation time and recorded data of each block are different. You can regard the blockchain as a bookkeeping book. Every once in a while, someone will write all the transaction information on the blockchain network to one page of the ledger, page by page, and record all the transactions on the blockchain network in turn according to the time
on the other hand, all nodes (computers in short) participating in the network will store one account book, which is updated in real time. Even if one node fails, the blockchain will not be affected.

4. Yes, but the hardware is constantly updated, so basically don't worry. A transaction only takes about 100 bytes, or 100 kb.

5. It depends on the project. Take bitcoin as an example. Now the account book that records all the information of bitcoin network may reach 220g.

6. Blockchain is a decentralized distributed record book and a credit data system. Its advantages are obvious
1. What the Internet changes is the acquisition and transmission of information, while what blockchain does is the transmission of value
for example, on the Internet, we can easily and quickly generate information and it to any place. All information can be spread efficiently, but some valuable information that can only be transferred but cannot be shared often needs credit endorsement
for example, we can't the payment directly to the other party, but we need to subtract some money from the payment account and add some money to the collection account to complete the payment process. The current Internet protocol does not support the function of value transfer. The current value transfer is not direct transmission. Instead, it is endorsed by a centralized third party, such as Alipay, such as banks.
now these centralized organizations put all the calculation of value transfer in a centralized server, which will certainly involve the participation of people, which will cause many problems, such as some "finite theory" and "opportunistic behavior", which will make the whole behavior less credible. So there is a basic question, how to reach a credit consensus
this is how blockchain technology came into being. It can be said that blockchain can build a pure point-to-point value transfer system. Without the mutual trust of each node, blockchain can ensure the integrity and security of data records in the system, and can be separated from the endorsement of third-party organizations, effectively recing the complexity and risk of transactions
2. It is open and transparent, and can not be tampered with
all data of the blockchain can not be tampered with or deleted, and the information of the whole system is open and transparent. If someone owes you a sum of money, and now the data has been put on the blockchain, if he doesn't want to return it to you and play a rogue with you, you can go to the court to protect your rights through the data forensics on the blockchain, so as to get back your legitimate funds. Because the data on the blockchain is open to the whole network, the users of the whole network will know his rogue behavior, which will greatly increase his credit cost. Dishonesty will make him have an important impact in the next life.

7. Blockchain originated from Nakamoto's bitcoin. As the underlying technology of bitcoin, it is essentially a decentralized database. It refers to the technical solution of collective maintenance of a reliable database through centralization and distrust in the past
blockchain technology is a technology solution that does not rely on a third party and stores, verifies, transmits and communicates network data through its own distributed nodes. Therefore, from the perspective of financial accounting, some people regard the blockchain technology as a distributed, open and decentralized large-scale network bookkeeping book. Anyone can use the same technical standards to add their own information at any time, extend the blockchain, and continuously meet the data entry needs brought by various needs
generally speaking, blockchain technology refers to a way for the whole people to participate in bookkeeping. There is a database behind all the systems. You can think of the database as a big ledger. So it's very important who keeps this account book. At present, whose system will keep accounts, wechat's account book is Tencent's account book, and Taobao's account book is Ali's account book. But now in the blockchain system, everyone in the system can have the opportunity to participate in bookkeeping. If there is any data change in a certain period of time, everyone in the system can conct bookkeeping. The system will judge the person who has the fastest and best bookkeeping in this period, write the content of his records into the account book, and send the content of the account book to all other people in the system for backup. In this way, everyone in the system has a complete account book. This way, we call it blockchain technology
blockchain technology is considered to be the most disruptive technological innovation since the invention of the Internet. Relying on the ingenious distributed algorithm of cryptography and mathematics, it can make the participants reach a consensus without the intervention of any third party center on the Internet where the trust relationship cannot be established, and solve the problem of reliable transmission of trust and value at a very low cost
bitcoin peer-to-peer network stores all transaction history in "blockchain". The blockchain continues to extend, and once new blocks are added to the blockchain, they will not be removed. Blockchain is actually a distributed database composed of a group of scattered client nodes and all participants, which is a record of all bitcoin transaction history. After bitcoin transaction data is packaged into a "data block" or "block", the transaction is initially confirmed. When a block is linked to a previous block, the transaction is further confirmed. After six block confirmations in a row, the transaction was irreversibly confirmed
blockchain is public on the network and can be queried in every offline bitcoin wallet data. The lightweight bitcoin wallet uses online confirmation, that is, it will not download the blockchain data to the device storage
digital currency is easy to be regarded as a new currency by traditional financial institutions, but in fact, the significance and value of its underlying technology is far greater than its monetary attribute. Taking bitcoin as an example, it is generally regarded as a kind of point-to-point digital currency, but from the technical level, it is actually a point-to-point decentralized network platform, which relies on the blockchain technology. Digital currency is a global peer-to-peer network platform based on blockchain technology. Represented by bitcoin, the application of blockchain in the field of digital currency is also known as blockchain 1.0 [1].

8. MD5? That is to check the integrity of BT files, authenticity, must have seeds to be able to download

9.

European certification

CE certification refers to the basic safety requirements of procts that do not endanger the safety of human beings, animals and goods, rather than the general quality requirements. The coordination directive only specifies the main requirements, and the general directive requirements are the tasks of the standard. Therefore, the exact meaning is: CE mark is a safety qualification mark, not a quality qualification mark. It is the core of the European directive; Main requirements & quot

"CE" mark is a kind of safety certification mark, which is regarded as the passport for manufacturers to open and enter the European market. CE stands for the unity of Europe

significance:

since the emergence of CE mark in 1995, CE mark has always symbolized the compliance of procts with EU laws no matter where they are proced in the world, and allowed the free circulation of the procts in the European economic area. CE mark is planned as a market supervision measure and has executive authority

The

CE mark indicates that the proct complies with all relevant directives of the European Commission. For example, most electronic procts must comply with low voltage directive and electromagnetic compatibility; Electronic toys are subject to additional toy safety instructions

The

CE mark does not indicate that the proct is proced by the European economic area. The manufacturer's CE mark on the proct indicates that the proct complies with all relevant requirements of the European Commission (e.g. safety, health, environmental protection, etc.) and has been verified by a third party designated organization

not all procts traded in EEA need CE mark. Only those commodities in the subordinate categories of the relevant directives need (and are recognized) CE certification. Most of the procts marked with CE mark can only be placed in the internal sales market controlled by the manufacturer, without independent proct consistency inspection according to the EU law. Anec warned consumers not to use the CE mark as a safety certification

CE mark is a self certification scheme, which means that the manufacturer or the importer is responsible for the proction process or the third-party test required, and bears criminal responsibility. From time to time, the government will carry out sampling inspection. If the procts are found to have problems, penalties can be imposed, including recycling of the procts, fines and even imprisonment

extended data:

scope of application

CPR regulations will apply to all construction procts sold and circulated in European market, such as doors and windows, wallpaper, building pigments, steel fiber, geotechnics, glass wool and other insulation materials, floor, roof materials, asphalt mixture, gypsum, concrete, cement, pipes, paving materials, sewerage equipment Doors and windows, glass, structural metal procts, fasteners, waterproof materials, structural wood

In addition to six basic performance requirements, European CPR also requires enterprises to prove the environmental sustainability of their construction procts

in addition to six basic performance requirements, the regulation also requires enterprises to prove the environmental sustainability information of their construction procts

not only that, but also on the basis of restricting the manufacturers of construction procts, the new regulations make new mandatory requirements for the links related to the circulation of construction procts, such as traders, importers and distributors, and provide a unified performance evaluation method for the construction procts entering the European Union, so as to ensure the reliability of the performance information of all construction procts by using a common technical language

the impact of EU CE certification CPR regulations on China

the new regulations mean that the restrictions on manufacturers, traders, importers and distributors will be more stringent. This has played a considerable role in further standardizing the EU market. China is a big country of building materials, and the European Union is one of the main export places of building materials. Instry insiders believe that the entry into force of this regulation will usher in new challenges to China's nearly 10 billion dollar building materials procts exported to the EU