PHP blockchain Ethereum

1.

what is Ethereum:

Ethereum is an innovation based on the application of technologies and concepts in bitcoin to computers. Ethereum itself imitates a lot of bitcoin technology to maintain the computer platform. blockchain technology is one of them
Ethereum platform can safely run any program users want

advantages of Ethereum over other competitive currencies before Ethereum appeared, some digital currencies imitated bitcoin. However, these projects have their own shortcomings, they can only support one or several specific applications at the same time< However, the reason why Ethereum can surpass the limitations of these projects in the past is because of the core idea of Ethereum

what Ethereum wants to implement is a blockchain protocol with built-in programming language. Since it supports programming language, in theory, any blockchain application can be defined with this language, and then run on Ethereum's blockchain protocol as an application

The design of Ethereum is very flexible and adaptable

Ethereum target sets the advantages of blockchain technology, in order to add the advantages of blockchain, such as decentralization, openness and security, to almost all computing fields

blockchain applications of Ethereum

Ethereum has many blockchain applications, such as digital applications of gold and stocks, financial derivatives applications, DNS and digital authentication, etc

Ethereum has achieved more than 100 blockchain applications by many start-ups

Ethereum has also been closely watched by some financial institutions, banking consortia (such as R3), as well as large companies like Samsung, Deloitte, RWE and IBM. As a result, a number of blockchain applications such as simplified and automated financial transactions, merchant loyalty index tracking, and gift cards designed to achieve decentralization of electronic transactions have emerged

the relationship between Ethereum and blockchain:

Ethereum is a programmable blockchain

Ethereum does not give users a series of preset operations (such as bitcoin transaction), but allows users to create complex operations according to their own wishes

in this way, Ethereum can be used as a platform for various types of decentralized blockchain applications, including but not limited to cryptocurrency

like other blockchains, Ethereum also has a peer-to-peer network protocol. Ethereum blockchain database is maintained and updated by many nodes connected to the network. Each network node runs the Ethereum simulator and executes the same instructions. Therefore, people sometimes call Ethereum "world computer"

2. curl方法，file_get_contents,

3. Through curl to simulate, and then get the data, and use it in JSON format

4.

Ethereum specifies the JSON RPC API application development interface that each node needs to implement. This interface is transport independent. Applications can use this interface protocol to operate Ethereum nodes through HTTP, websocket or IPC and other communication mechanisms:

5.

bus line: Line 1 → line 3, the whole journey is about 20.0km

1. Walk about 590m from Nanshan sports center to Taoyuan station

2. Take Line 1, pass 10 stops, reach Shopping Park Station

3, walk about 180m, transfer to line 3

4. Take line 3, pass 4 stops, reach Huaxin station

5, walk about 360m, reach shengtingyuan hotel

6. Why not dig bitcoin BTC instead of bitcoin VTC? At present, many large-scale mines abroad have allocated one third of their computing power to dig special coins. What is the reason for this
let me analyze it:
1: bitcoin has been broken in China, and its price has dropped sharply, which is unexpected by the global mining pool
2: compared with the current mining cost of bitcoin, it makes money entirely by cheap electricity bills
3: there are only 21 million bitcoins, and most of them have been g up in the early stage, which makes it difficult to dig those bitcoins that have not been g up in the future, and there is too much competition. Many small mines are in a state of loss
and why do many well-known mines turn to TCD
first of all, bitcoin is the optimized and upgraded version of bitcoin, with a constant number of 100 million. The early mining is very good. Unlike bitcoin, which has too high cost and low cost performance ratio, it is appropriate to use bitcoin as a supplement to compare bitcoin. Bitcoin is used for large amount payment and bitcoin is used for small amount payment.

7.

Yes

use PHP code to define blocks:

class block {

public $prevhash

public $hash;

public $timeStamp;

public $data;

}

prevhash: the hash value of the previous block; Hash: hash value of the current block; Timestamp: the time stamp generated by the block; Data: data stored in the block; The fields prevhash, hash and timestamp are called block headers in the blockchain, and the hash value of the block is calculated by SHA-256 algorithm

extended data

the practical use and significance of blockchain:

blockchain is a decentralized distributed ledger. What is decentralization? There is no center, or everyone can be a center. This is different from the traditional way of centralization. Distributed ledger means that the storage of data is not only on each node, but each node will and share the data of the whole ledger

In addition, blockchain has the characteristics of disintermediation and information transparency. For example, for example, when we shop on Taobao, after we place the order, the cost we pay is first hit in Alipay. After we receive the courier and confirm the receipt, the money will be transferred to the seller's account. In the blockchain, buyers and sellers can trade directly without any platform as a third-party certification authority

the system will broadcast the transaction information of both parties. All hosts will record and back up the transaction data after receiving the information. If the order of one machine is wrong, the backup data of other machines will not be affected

8. < UL >

the concept of blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Since it is a mode, it is not limited to language, only that language is more suitable

blockchain needs a lot of storage, calculation and transmission. PHP is not suitable for these characteristics, especially the efficiency of PHP

if you want to study this, look at the article of blockchain more:

understanding of blockchain,

51 lines of code to realize a simple PHP blockchain

< / UL >

9. Ethereum is also a proct of blockchain 2.0, which is an open intelligent contract complete solution. Bitcoin is the most important application of blockchain 1.0, which completes currency and payment transactions well. But when we need to record and transfer more complex asset types, we need the third step - a more powerful scripting system - to finally achieve Turing completeness (the ability to run any currency, protocol or blockchain). Ethereum is a blockchain based project, which aims to provide a Turing complete scripting language and Turing complete platform

blockchain 1.0 mainly refers to bitcoin. Blockchain 2.0 extends to all assets, while blockchain 3.0 goes beyond currency, finance, even commerce, and all areas of our lives, including politics, social relations, ecation, medical care, etc. According to the prediction and conception of people in the instry, the era of blockchain 3.0 will be realized in the next five years. At that time, blockchain will be recognized and accepted by all the public like the Internet, thus completely subverting our lives

McKinsey has submitted a technical report on blockchain to the Federal Insurance Advisory Committee of the United States. The report calls 2009-2016 the "Dark Age" and believes that all blockchain solutions ring this period are based on bitcoin, and the new era of blockchain will begin in 2016. At that time, the application of blockchain will become unprecedented. Applying an original sentence in McKinsey report: Based on the current development speed of blockchain, we believe that blockchain solutions may realize their full potential in the next five years.