Blockchain database
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
constructor(index,timestamp,data,previousHash='&# 39;)< br />{
this.index=index;< br />this.timestamp=timestamp;< br />this.data=data;< br />this.previousHash=previousHash;< br />$this.hash=this.calculateHash();< br />}
calculateHash(){
return SHA256(this,index+this.previousHash+this.timestamp+JSON.stringify(this.data)).tostring();< br />}
}
class Blockchain{
constructor(){
this.chain=[this.createGenesisBlock()];<
}
/ / create a generated information block
creategenesis block() {
return new block (0, & quot; 01/01/2019",& quot; Genesis block", 0);
/ / the date is the user's data. In fact, it is the hash value obtained by adding several values together. Here, the information is encrypted and the picture is encrypted. Then the data is still stored in the database, but all the data are hash values. To get this data, you must know the hash value of the previous data block. Then, if the hacker needs to crack all the nodes, the hash value is decrypted, Then all the blocks from the first node to the last node can be decrypted to get the real data. So the security of data stored in the blockchain depends on whether the data is encrypted. If the plaintext is not encrypted, then it is not a blockchain
}
/ / get the last block
getlatesblock() {
return this.chain [this.chain. Length-1]
}
/ / create block
addblock (newblock) {
newblock. Previoushash = this. Getlatesblock(). Hash< br />newBlock.hash=newBlock.calculateHash();< br />this.chain.push(newBlock);< br />}
}
bitcoin trading platform has many running platforms, such as mtgox in Japan, bitcoin in China and so on
therefore, investors need to choose a reliable bitcoin trading platform. The reference factors are: 1. The longer the running time, the better; 2. The bigger the instry reputation, the better; 3. The larger the team size, the better; 4. Being able to visit<
it is suggested that China choose "fire coin net", which is cooperated by Wukou School of finance of Tsinghua University. Sequoia Capital has invested 10 million US dollars; The choice of coinbase in foreign countries is an important choice for Silicon Valley banks to invest.
College Students' innovation and entrepreneurship ideas include printing and ing services, leisure errands, school leisure food stores, college students' Tutoring instry, and online stores 1. Printing and ing service in fact, many schools have printing and ing stores. It seems that the market is saturated, but in fact, there is still a lot of space. Especially in the graation season, students have to print various reports, resumes and other information. The key to starting a business is to find the right location 5. Setting up shop on the Internet the sales volume of health care instry on the Internet is even more considerable than that of books and music. Buying daily necessities on the Internet is often favored by people because it can avoid the curious eyes of people on the street and face the situation of salesmen extended materials precautions 1, risk perception the risk perception of entrepreneurs depends on the entrepreneur's self-confidence, independent of plan, desire for control and other factors. Only those who have the courage to take risks can meet the challenges, invest their time, energy and financial resources and bear the possible losses 2. Alertness is also called entrepreneur early warning, which is used to reflect the ability of entrepreneurs to find out whether market opportunities exist or whether they have value. When one person has insight into the value of a resource while others don't, the warning has already appeared
Internet plus is an outdated word. Who is still talking about this word? p>
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the half hanging teacher in Colleges and universities, who couldn't find a good job in those years, was reluctant to bear hardships and went to the school to be a teacher, and then gave all kinds of advice, which is called "mistaking the children". What kind of entrepreneurship competition is also a laughing matter. All kinds of old ideas are on the table. They have no experience in social work. How can they talk about entrepreneurship? Of course, colleges and universities also have strong teachers, or academic strong, they will not talk about entrepreneurship with you. Either I have worked outside for a long time, worked as a leader, and become a teacher; Another is to realize financial freedom early. What the three groups do not do is Internet plus, because the word is out of date. p>
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ZF officials declined to comment
< / OL >
Why do I say this word is out of date? Go and see what is the hot field of venture capital, that is, the so-called tuyere
1, AI, has been fried for many years. This year,
2 is specially
2 and share the economy. Now it is in the red sea state. It can be regarded as the Internet Plus +
3, block chain technology
4, lithium battery and new energy vehicle, and is beginning to mature. p>
5. Fintech, Alibaba has long said that it is not engaged in Internet finance, but copied a foreign word, called financial technology company
the level of judges in the entrepreneurship competition is too low. Even if college students win the championship in the competition, they are in the wrong direction
if you want to start a business competition, you have to invite angel investors, PE, VC, at least those who have been in these companies, or else you are going to have a family