Ethereum block binary

1.

virtual currency is the currency used for electronic circulation. Now the scope of virtual currency is very large, including q-coin, bitcoin and so on. With the development of digital currency, virtual currency is becoming more and more abundant, which may become the mainstream in the future. For example, BTC, EOS, bcbot and so on are not only virtual currencies, but also algorithms, landing projects and technologies

virtual currency is mainly issued by online game service providers to purchase game props, such as equipment, clothing, etc. But at present, the use of virtual currency has gone far beyond this category. Virtual currency can be used to buy game cards, physical objects and download services of some movies and software

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real risk

as the proct of e-commerce, virtual currency has begun to play an increasingly important role, and it is more and more connected with the real world. However, with the growth of virtual currency, the relevant laws and regulations are lagging behind, which has laid many hidden dangers

fraud

the private transaction of online virtual currency has realized the two-way circulation between virtual currency and RMB to a certain extent. The activity of these traders is to buy all kinds of virtual currencies and procts at a low price, and then sell them at a high price to earn profits. With the increase of such transactions, there are even virtual mints. In addition to the virtual currency provided by the main company, there are also some people who specialize in "virtual coin making" to obtain virtual currency by playing games and then resell it to other players

Taking Wenzhou as an example, there are about seven or eight such "virtual mints" with four or five hundred practitioners. This not only creates a bubble for the price of the virtual currency itself, but also causes trouble for the normal sale of the issuing company. It also provides a platform for selling and collecting money and money laundering for various cyber crimes. p>

impact system

in modern financial system, the issuers of money are generally central banks, which are responsible for the management and supervision of money operation. As the equivalent exchange goods used to replace the real currency circulation on the Internet, the virtual currency on the Internet is essentially the same as the real currency. The difference is that the issuers are no longer central banks, but Internet companies

if the development of virtual currency makes it form a unified market, each company can exchange with each other, or virtual currency is integrated and unified, and all of them are based on the same standard and price, then in a sense, virtual currency is currency, which is likely to form a threat impact on the traditional financial system or economic operation

reference: network virtual currency

2. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)

3.

Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects

on January 10, 2019, the state Internet Information Office issued the regulations on the management of blockchain information services. In October 24, 2019, ring the eighteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that "block chain as an important breakthrough in core technology and independent innovation", "accelerating the development of block chain technology and instrial innovation". "Blockchain" has entered the public field of vision and become the focus of social attention

on December 2, 2019, the word was selected into the top ten catchwords of "biting words" in 2019

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Application of blockchain Finance:

since 2016, the major financial giants have also carried out blockchain innovation projects to explore the possibility of applying blockchain Technology in various financial scenarios. In particular, Puyin group took the lead in creating a "blockchain +" standard digital currency

standard digital currency refers to the process of assets identification, evaluation, right confirmation and insurance completed by a third party organization, which is written into the blockchain through careful digital algorithm to form the standard corresponding relationship between assets and digital currency, which is called standard digital currency

in order to realize the great leap forward development of blockchain finance, promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that has been struggling for generations, Puyin group will hold the Guiyang strategic development ceremony of Puyin blockchain finance in Guizhou on December 9, 2016

the meeting will discuss the realization of digital circulation of assets by blockchain, the financial transaction mode of blockchain, and the application of blockchain services and social public instry. This conference will mark the beginning of the application of blockchain finance and the change and development of the new financial ecology

4. Introction to seven core technologies of blockchain operation on January 15, 2018
1. Blockchain links
as the name suggests, blockchain is a chain composed of blocks. Each block is divided into block head and block body (including transaction data). The block head includes the prevhash value (also known as hash value) of the previous block used to realize the block link and the random number (nonce) used to calculate the mining difficulty. The hash value of the previous block is actually the hash value of the head of the previous block, and the random number calculation rule determines which miner can obtain the right to record the block
2. Consensus mechanism
blockchain is accompanied by the birth of bitcoin, which is the basic technology architecture of bitcoin. Blockchain can be understood as an Internet-based decentralized accounting system. A decentralized digital currency system like bitcoin requires the consistency of accounting of honest nodes without a central node, which needs blockchain to complete. Therefore, the core of blockchain technology is a consensus mechanism to reach a consensus on the legitimacy of transactions between indivials without mutual trust without central control
there are four main types of consensus mechanisms in blockchain: pow, POS, dpos and distributed consistency algorithm
3. Unlocking script
script is an important technology to realize automatic verification and contract execution on blockchain. Every output of every transaction does not point to an address in the strict sense, but to a script. A script is like a set of rules that constrain how the receiver can spend the asset locked on the output
the validation of transactions also depends on scripts. At present, it depends on two kinds of scripts: Lock script and unlock script. Locking script is a condition added to the output transaction, which is realized by a script language and located in the output of the transaction. The unlocking script corresponds to the locking script. Only when the conditions required by the locking script are met can the assets corresponding to the script be spent, which is located in the input of the transaction. Many flexible conditions can be expressed by script language. Interpretation script is similar to the "virtual machine" in our programming field, which runs in every node of the blockchain network in a distributed way
4. Transaction rules
blockchain transaction is not only the basic unit of a block, but also the actual effective content recorded by the blockchain. A blockchain transaction can be a transfer, or the deployment of smart contracts and other transactions
as far as bitcoin is concerned, a transaction refers to a single payment transfer. The transaction rules are as follows:
1) the input and output of the transaction cannot be empty
2) for each input of a transaction, if its corresponding utxo output can be found in the current transaction pool, the transaction will be rejected. Because the current transaction pool is the transaction not recorded in the blockchain, and each input of the transaction should come from the confirmed utxo. If it is found in the current trading pool, it is Shuanghua trading
3) for each input in a transaction, the corresponding output must be utxo
4) each input unlocking script must verify the compliance of the transaction together with the corresponding output locking script
5. Transaction priority
the priority of blockchain transaction is determined by the blockchain protocol rules. For bitcoin, the priority of a transaction to be included in a block is determined by the time when the transaction is broadcast to the network and the amount of the transaction. With the increase of transaction broadcast time on the network and the increase of transaction chain age, the priority of transaction will be improved and eventually be included by the block. For Ethereum, the priority of the transaction is also related to the transaction fee that the publisher is willing to pay. The higher the transaction fee that the publisher is willing to pay, the higher the priority that the transaction is included in the block
6. Merkle proof
the original application of Merkle proof is bitcoin, which was described and created by Satoshi Nakamoto in 2009. Bitcoin blockchain uses Merkle proof to store transactions in each block. So that the transaction can not be tampered with, but also easy to verify whether the transaction is included in a specific block
7. RLP
RLP (recursive length prefix) is one of the main encoding methods of object serialization in Ethereum. Its purpose is to encode the sequence of arbitrary nested binary data.

5.

Bitcoin is a kind of virtual encrypted digital currency in the form of P2P. Different from all currencies, bitcoin does not rely on specific currency institutions. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, And the use of cryptography design to ensure the security of all aspects of money circulation. However, on September 4, 2017, the central bank and other seven ministries and commissions announced that virtual currency trading is prohibited in China, and bitcoin is prohibited from circulating in China

according to the first article of the notice on preventing the financing risks of token issuance, we should accurately understand the essential attributes of token issuance financing activities. Token issuance financing refers to the illegal sale and circulation of tokens by the financing subject to raise the so-called virtual currency such as bitcoin and ether coin from investors. In essence, it is an unauthorized illegal public financing behavior, which is suspected of illegal sale of token bills, illegal issuance of securities, illegal fund-raising, financial fraud, pyramid schemes and other illegal criminal activities

Relevant departments will closely monitor relevant developments, strengthen cooperation with judicial departments and local governments, strictly enforce the law in accordance with the current working mechanism, and resolutely deal with market chaos. If suspected crimes are found, they will be transferred to judicial organs. The token or "virtual currency" used in token issuance financing is not issued by the monetary authority, does not have such monetary attributes as legal compensation and compulsion, does not have the same legal status as currency, and cannot and should not be used as currency in the market

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Article 3 of the announcement on preventing the financing risk of token issuance strengthens the management of token financing trading platform. From the date of this announcement, any so-called token financing trading platform shall not engage in the exchange business between legal tender and token and "virtual currency", nor buy or sell token or "virtual currency" as a central counterpart, nor provide pricing, information intermediary and other services for token or "virtual currency"

for the token financing trading platform with illegal problems, the financial management department will request the competent department of telecommunications to close its website platform and mobile app according to law, request the network information department to remove the mobile app from the app store, and request the instrial and commercial administration department to revoke its business license according to law

Article 4 financial institutions and non bank payment institutions shall not carry out business related to token issuance financing transactions. All financial institutions and non bank payment institutions shall not directly or indirectly provide procts or services such as account opening, registration, trading, clearing and settlement for token issuance and financing and "virtual currency", nor undertake insurance business related to token and "virtual currency" or include token and "virtual currency" into the scope of insurance liability. Financial institutions and non bank payment institutions shall report to the relevant departments in a timely manner if they find clues of violation of laws and regulations in token issuance financing transactions

6.

blockchain is a decentralized distributed ledger database . The advantage of this distributed ledger is that buyers and sellers can trade directly without any intermediary. Everyone has a backup, even if you lose this, it will not be affected

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blockchain application field

1, financial field

blockchain has potential huge application value in international exchange, letter of credit, equity registration, stock exchange and other financial fields. The application of blockchain technology in the financial instry can save the third-party intermediary link and realize the point-to-point direct docking, so as to greatly rece the cost and quickly complete the transaction payment

2. The Internet of things and logistics

blockchain can also be naturally combined in the field of Internet of things and logistics. Through blockchain, we can rece logistics costs, trace the proction and delivery process of goods, and improve the efficiency of supply chain management. This field is considered as a promising application direction of blockchain

3. The data stored on the public welfare field

blockchain is highly reliable and tamperable, which is naturally suitable for social public welfare scenarios. The relevant information in the public welfare process, such as donation project, collection details, fund flow, recipient feedback, etc., can be stored on the blockchain, and can be made transparent and public, which is convenient for social supervision

4. In the field of insurance

in terms of insurance claims, insurance institutions are responsible for fund collection, investment and claims settlement, and often have higher management and operation costs. Through the application of smart contract, there is no need for the applicant to apply or the insurance company to approve. As long as the claim conditions are triggered, the automatic claim settlement of the policy can be realized

7. The configuration of the first network card in Linux system
description of ifcfg-eth0 configuration parameters in Linux:
ifcfg-eth0 is in / etc / sysconfig / network scripts,
its configuration is as follows:
device = physical device name
IPADDR = IP address
netmask = mask value
Network = network address
broadcast = broadcast address
gateway = gateway address
onboot = [yes | no]
userctl = [yes | no] (whether non root users can control the device)
bootproto = [none | static | BOOTP | DHCP] (boot) No protocol | static allocation | BOOTP protocol | DHCP protocol)
hwaddr = MAC address
some parameters are not required
the original configuration is as follows:
device = eth0
bootproto = DHCP
onboot = yes
in this case, the NIC is not activated
the modified configuration is as follows:
device = eth0
bootproto = static
broadcast = 192.168.129.128
IPADDR = 192.168.129.2
netmask = 255.255.255.0
Network = 192.168.129.0
onboot = yes
in this way, the network card can be activated every time it is turned on.

8. Region chain is a kind of data structure, independent of specific language. Using C + + is to consider a large number of mathematical operations, such as encryption and decryption operations, a large number of numerical operations, high precision requirements, stable performance, anti decompilation, anti tampering, anti tracking, fast speed, these are the advantages of C + +
for the same complex algorithm, C + +, C #, Java are written in one version respectively, and C + + is bound to be better in performance. The core algorithm uses Java to write bytecode and C to write MSIL (Microsoft Intermediate Language) are easy to be decompiled. And C + + write directly compiled into binary, and binary even if you get it, how can?

9.

Transaction

the behavior of blockchain transaction follows different rule sets

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e to the distributed and unlicensed nature of public blockchain, anyone can sign the transaction and broadcast it to the network

according to different blockchains, traders will be charged a certain transaction fee, which depends on the needs of users rather than the value of assets in the transaction

blockchain transactions do not require any central authority verification. It only needs to use the digital signature algorithm (DSA) corresponding to its blockchain to sign it with the private key

once a transaction is signed, broadcast to the network and mined into a successful block in the network, the transaction cannot be recovered

Ethereum transaction structure

Ethereum transaction data structure: transaction 0.1 eth

{
& 39; nonce':&# 39; 0x00', // Decimal: 0
& 39; gasLimit': &# 39; 0x5208', // Decimal system: 21000
& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal system: 10000000000
& 39; to': &# 39;&# 39; ，// Sending address
& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17
' data': &# 39; 0x', // Decimal representation of null data; chainId': 1 / / blockchain network ID
}

these data have nothing to do with the transaction content, but have something to do with the execution mode of the transaction. This is because when you send a transaction in Ethereum, you must define some other parameters to tell miners how to handle your transaction. Transaction data structure has two attribute designs & quot; gas": & quot; gasPrice",& quot; gasLimit"

" gasPrice": The unit is Gwei, which is 1 / 1000 eth, indicating the transaction cost

& quot; gasLimit": The maximum gas charge allowed for the transaction

these two values are usually filled in automatically by the wallet provider

in addition, you need to specify which Ethereum network to execute the transaction (chainid): 1 represents the Ethereum main network

ring development, tests are usually carried out locally and on the test network, and transactions are carried out through the test eth issued by the test network to avoid economic losses. After the test, enter the main network transaction

in addition, if you need to submit some other data, you can use & quot; data" And & quot; nonce" Attach as part of a transaction

a nonce (number used only once) is the value used by Ethereum to track transactions, which helps to avoid double spending and replay attacks in the network

Ethereum transaction signature

Ethereum transaction involves ECDSA algorithm. Taking JavaScript code as an example, the popular ethers.js is used to call ECDSA algorithm for transaction signature

const ethers = require(' ethers')

const signer = new ethers.Wallet(' Wallet address

signer.signTransaction({

' nonce':&# 39; 0x00', // Decimal: 0

& 39; gasLimit': &# 39; 0x5208', // Decimal: 21000

& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal 10000000000

& 39; to': &# 39;&# 39; ，// Sending address

& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17

' data': &# 39; 0x', // Decimal representation of null data

& 39; chainId': 1 / / blockchain network ID

})

. Then (console. Log)

you can use the online application composer to deliver signed transactions to Ethereum. This is known as "offline signature.". Offline signatures are particularly useful for applications such as status channels, which are smart contracts that track the balance between two accounts and transfer funds after a signed transaction is submitted. Offline signature is also a common practice in dexes

you can also use online wallet to create signature verification and broadcast through Ethereum account

with Portis, you can sign a transaction to interact with the gas station network (GSN)

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10. Unicareer's CEO is Yu Jia, who was just selected into the 2017 Asia 30 under 30 talent list a few days ago. Although young, but really good! He graated from Tongji University in Computer Engineering and Fudan University in financial engineering. In 2013, unicareer was founded on Wall Street in New York and served as CEO. In the past three years, unicareer has grown into the largest online workplace ecation technology platform in North America, obtaining tens of millions of financing.