Wu Jihan BTC smart contract

blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum

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 bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:

1. The blockchain with the whole network open and without user authorization mechanism is called public chain

2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain

3. All the nodes in the network are in the hands of one organization, which is called private chain

alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain

blockchain features

1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain

2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent

3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention

4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes

5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously

BTC bitcoin

bitcoin is the first distributed digital asset platform created. Since its launch in 2009, it has proven to be not only the most popular, but also the largest market capital value. In addition, it is also the most expensive, with a value of $10710 per coin on February 17, 2018. Bitcoin introces the first blockchain distributed ledger dedicated to recording all transactions, and gets rid of the function that users need a central authority to process or verify transactions

its goal is to provide a platform for users to conct cross-border transactions without any intermediary, which is what we call decentralization. The platform's largest money (BTC) supply is about 21 million. Of this figure, about 16.5 million have been mined and are now in circulation. It is mined all the time around the world to ensure the circulation of coins

1. Its distributed system provides users with great freedom

2. High portability

disadvantages:

1

2. The user may lose the key

eth Ethereum

Ethereum is also a distributed platform, which was created by Network Programmer vitalik buterin in July 2015. Ethereum aims to enable users to create and deploy smart contracts. One of the main functions of smart contracts is to allow the creation of encrypted assets or tokens running on Ethereum networks. Ethereum token is used to purchase various functions such as cloud storage space. These tokens are stored in a digital wallet compatible with Ethereum blockchain

Ethereum's digital currency ether serves as the medium for executing smart contracts. At present, about 98 million ether coins have been mined and circulated, and the circulation supply increases by about 18 million every year. Ethernet coin is created to run on the Ethereum network. It can be used to compensate the participant nodes or transfer from one user to another

advantages:

1

2

disadvantages: large circulation

generation principle:

starting from the essence of bitcoin, the essence of bitcoin is actually a special solution generated by a bunch of complex algorithms. A special solution is one of the finite solutions of a system of equations. Every particular solution can solve the equation and is unique

in the metaphor of banknotes, bitcoin is the number of the top word of a banknote. The number of the top word on a banknote owns the banknote. The process of mining is to constantly seek the special solution of the equation system through huge amount of calculation. The equation system is designed to have only 21 million special solutions, so the upper limit of bitcoin is 21 million

to mine bitcoin, you can download the special bitcoin computing tools, register various cooperation websites, fill the registered user name and password into the computing program, and then click the operation to officially start

after completing the installation of bitcoin client, you can directly obtain a bitcoin address. When others pay, you only need to post the address to others, and you can pay through the same client

after installing the bitcoin client, it will assign a private key and a public key. You need to back up the wallet data containing your private key to ensure that your property is not lost. Unfortunately, if the hard disk is completely formatted, personal bitcoin will be completely lost

BTC, usdt, ETH, BCH, LTC mean respectively:

1, BTC

bitcoin. The concept was first proposed by Nakamoto in 2009. According to Nakamoto's idea, the open source software is designed and released, and the P2P network is built on it. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system

2, usdt

TEDA currency is a virtual currency that links cryptocurrency with legal currency US dollar, and is a virtual currency kept in foreign exchange reserve account and supported by legal currency

Ethereum is an open source public blockchain platform with intelligent contract function, which provides decentralized Ethereum virtual machine to process point-to-point contract through its special cryptocurrency ether

4. BCH

bitcoin cash is a new version of bitcoin with different configurations launched by a small number of bitcoin developers

at 20:20 on August 1, 2017, bitcoin cash starts mining, and each bitcoin investor's account will have the same amount of bitcoin cash (BCH)

5, LTC

litecoin, abbreviated as LTC, currency symbol: & # 321;; It is a kind of network currency based on "peer-to-peer" technology. It is also an open source software project under MIT / X11 license. It can help users make instant payments to anyone in the world

source of reference: network bitcoin

source of reference: network TEDA coin

source of reference: network Ethereum

source of reference: network bitcoin cash

source of reference: network letcoin

source of reference: Network