What is a digital currency vhash
transaction security technology includes anonymous technology, identity authentication technology, anti plicate transaction technology and anti-counterfeiting technology. Anonymity technology realizes controllable anonymity of digital assets through blind signature (including blind parameter signature, weak blind signature, strong blind signature, etc.) and zero knowledge proof; The identity authentication technology verifies the user's identity through the authentication center to ensure the validity of the digital asset trader's identity; The anti plicate transaction technology ensures that digital assets are not reused by means of digital signature, serial number and time stamp; Anti counterfeiting technology ensures the authenticity of digital assets and transactions by means of encryption and decryption, digital signature and identity authentication. Secondly, the online transaction and offline transaction of digital assets are realized by transaction technology. Digital asset trading technology mainly includes online trading technology and offline trading technology. As a legal currency, digital assets should not be rejected by any unit or indivial, and can be traded online or offline. Online transaction technology realizes online transaction of digital assets through online device interaction technology, online data transmission technology and online transaction processing; The off-line transaction technology realizes the off-line transaction of digital assets through the off-line device interaction technology, off-line data transmission technology and off-line transaction processing technology. Finally, trusted guarantee technology is used to provide a safe and reliable application environment for the issuance, circulation and transaction of digital assets in blockchain. Digital asset trustworthiness assurance technology mainly refers to trusted service management technology. Based on trusted service management platform (TSM), it ensures the security and trustworthiness of digital asset security mole and application data, and provides security chip (SE) and application life cycle management function for digital asset participants. Trusted service management technology can provide application registration, application download, security authentication, authentication management, security evaluation, trusted loading and other services for digital assets, which can effectively ensure the security and credibility of digital assets system
what is blockchain? Blockchain technology, also known as distributed ledger technology, is an Internet database technology, which is characterized by decentralization, openness and transparency, so that everyone can participate in database records. Blockchain technology development blockchain technology development what is a blockchain system? Blockchain system is a database system with integrity. The data written into the system will be automatically copied to the nodes of the blockchain, which can achieve transactional data preservation, support the management and development of databases in various instries, and be proced in combination with various needs. 294.497 billion US dollars, or 2.60%. This week, five new projects entered the top 100, namely FST, ZB, Wix, wax and MXM. On August 11, the price of bitcoin was $11523.58, up 3.20% from last week, and Ethereum was $216.09, down 3.86% from last week. The 24-hour turnover of this week increased by 2.63% over the same period last week; Among the top 100 projects, the total market value and average market value of currency projects increased significantly, and the classification composition of global blockchain assets top 100 projects was stable.
1. Litecoin is similar to bitcoin, which is also an encrypted digital currency, and its price has risen sharply recently. It is a P2P open source digital currency, which can be regarded as a branch of bitcoin. However, although lightcoin is based on bitcoin protocol, it does not require very high computing power. It can also be mined using ordinary computers. Lightcoin's algorithm comes from the algorithm designed by Dr Colin Percival for tarsnap secure online backup service (backup for Linux and other open source operating systems)
2. Namecoin
namecoin is also based on bitcoin, which is another branch of open source. Namecoin is a distributed DNS protocol -- generally speaking, it can transform the website name (such as ifeng. Com) that can be understood by human into the address that can be understood by machine. As its own DNS, this kind of currency can operate outside the normal Internet, so it can break away from the control of ICANN
the monetary value and domain name of namecoin are stored in the user's blockchain records, limiting the total number to 21 million
3. Peercoin
peercoin is a peer-to-peer variant of bitcoin, which can improve mining efficiency and security, and improve safeguard measures to avoid group mining. Now, group mining has been considered as a potential defect of bitcoin. According to the statistics of emerging currencies by coinmarketcap.com, peercoin currently ranks fourth in the market value of digital currencies
4. Primecoin
primecoin is a cryptocurrency similar to bitcoin, but it uses a completely independent mining algorithm. Bitcoin uses the hashcash algorithm, while prime coin uses the long Cunningham chains to create the value of money - a sequence of prime numbers named after mathematician AJC Cunningham
in the process of bitcoin mining, as the amount of money goes on, the difficulty will increase sharply. But prime is different. Every time a primecoin is mined, the mining difficulty will increase slightly, and the process is much more stable< 5. Feathercoin
based on the design of litecoin, released in April 2013, can adjust the mining difficulty more frequently than litecoin. Feathercoin will be updated frequently, adding new features and improvements to eliminate malicious mining behavior
6. Novacoin
another P2P digital cryptocurrency. Novacoin is different from most other currencies in that it integrates a protection mechanism in the currency core, which can identify illegal mining activities
the total number of novacoin is limited to 2 billion, which is considerable. If necessary, the total can be adjusted upward
7, infinitech
published in June 2013. A by-proct of litecain. According to the mining situation and the total amount of money, infinite money can frequently adjust the mining difficulty ratio< Megacoin was only released in the fourth quarter of 2013, imitating bitcoin in the early stage. The total number of megacoin is limited to 42 million, which can be mined like other virtual currencies. Its biggest selling point is brand publicity, which other digital currencies lack< It was released in 2013 and is still in its infancy. In the security part of quarkcoin, nine independent loops are deployed and six different algorithms are used.
The wealth myth of "one coin, one villa" is still widely spread in the currency circle, and new investors are eager to try. But in fact, a stable power structure has been formed in this small circle, from mining machinery manufacturers to large mine owners, and then to mining pools
manufacturing and selling mining machines, mining, building mines and building ore pools, the "mining circle" has become another way to get rich in the blockchain world, and mining machines have also become a little-known "big business"
according to the imagination of Nakamoto, the inventor of bitcoin, the ideal state should be "decentralized", with computing power scattered all over the world. However, contrary to decentralization, the mine pool is absolutely centralized, and more and more mining machines are connected to the mine pool
this article was first published in the Southern Weekend
"if speculation is a road of no return, then investment in mining machinery is a business that can make a steady profit without loss, and it is only a matter of time before the cost is recovered." Zhong Xi, general manager of Shenzhen Aibo times Technology Co., Ltd., calculated an account. A miner earns 200 yuan a day, which can be recovered in 120 days, and then the profit
in October 2017, in addition to his main business, Zhong Xi joined the mining army and quickly became a big boss in the mining circle. He operated many large mines in Jiangxi, Sichuan, Guizhou and other places
in fact, the business of "steady profit without loss" still depends on the continuous rise of currency price. In the past two months, the price of bitcoin has dropped from US $15000 to about US $10000, or even below US $6000 at one time, which has extended the cycle of mining machinery return. If it keeps falling, the profit will be far away
in 2012, four years after the advent of bitcoin, mass-proced mining machines appeared. Before that, mining was mainly a private activity, which could be completed by a home computer“ At that time, the home computer was the money printing machine, and a lot of bitcoin could be g up every day. " Huang Shiliang, a senior digital currency player who sold mining machines in his early years, recalled to Southern Weekend reporters
after the emergence of mining machine, mining began to be "socialized", with the emergence of mines and pools, and mining became a collective work. The indivial miner is entrusted by the mine, just like the workers on the proction line, as long as they are there, they can get paid every day
manufacturing and selling mining machines, mining, building mines and building ore pools, the "mining circle" has become another way to get rich in the blockchain world, and mining machines have also become a little-known "big business"
China has become the world's largest procer of mining machinery. Since 2012, a number of miner manufacturers have been born in China, such as Shenzhen bitquan Co., Ltd., which proces cat roasting miner, bitmainland, Jianan Yun and Yibang communication, which are now famous. In Huaqiangbei, Shenzhen, foreigners can be seen everywhere asking about the price of mining machinery with translators
recently, in an interview with the media, the CEO of bitcontinental, Mr. Zhan Ketun, said that this startup company, which has been established for only four years, had a revenue of about US $2.5 billion in 2017. Bitcontinent is known as the world's largest miner, whose ant miner has always been the hard currency of the coin circle and miner world
just like the coin circle, the mining circle also needs belief that the mechanical mathematical operation of mining machines every day can create great wealth
However, contrary to the "decentralization" advocated by bitcoin, the miner's world is moving towards "centralization". Miner dealers build their own mines. After the investors buy the miner, they are entrusted by the seller; The procers build their own mines and manage themthis process of "centralization" made the wealth of the mining circle snatched by a few people, and it was not easy for Zhong Xi to enter the core circle
calculation force "centralization"
the main function of the mine is to provide a place for scattered mining machines to operate. But it is the "ore pool" that really plays the role of integration
the so-called "mine pool" can be simply understood as "cooperative mining". The miners and the mines give the calculation power to the mine pool, and the mine pool is used as the only address to access the digital currency network for mining, and then distribute dividends to the miners according to the calculation power of the mining machine
the history of ore pool is longer than that of mining machine. In November 2010, the mine pool named slush appeared. Today, its official website says "the world's first mine pool", which is also recognized by the coin circle. Compared with the mine, the construction of the mine pool needs certain technology, and the threshold is relatively higher
the person in charge of a well-known domestic mine pool explained the principle of the mine pool to the Southern Weekend reporter. He compares mining to buying lottery tickets. If you dig alone, the probability of winning the lottery is very unstable. You may win 100000 today, but you won't in the next six months
"gather the people who buy lottery tickets together and buy them in a unified way. No matter who wins, they will be divided according to the proportion of money they pay. In the coin circle, the mine pool plays this role. " The person in charge said
it's not complicated to connect the mining machine with the ore pool. According to the operation guidelines of the major ore pools, it can be completed in a few steps, and then according to the calculation power provided by ourselves, we can get benefits from the ore pool. The miner is like a worker standing on the proction line, receiving a fixed salary every day
the mine pool with huge computing power and many mining machines has an absolute say in the coin circle and the mining circle. For example, if you want to issue a new digital currency or dominate the bitcoin bifurcation, you generally need to get the support of the mine pool. Without the support of the mine pool, no one will dig the new currency, so it is meaningless
in addition, when a hot new coin comes out, the mine pool can also use its own miners to pack it quickly and take the lead in the rush purchase of these new coins
in June 2017, when SNT and EOS were issued, Southern Weekend reporters witnessed the scene of minchi snapping up tokens. Because there are too many investors, many indivial investors can not put their funds into the designated position, but the person in charge of a mine pool can easily complete this operation
according to the imagination of Nakamoto, the inventor of bitcoin, the ideal state should be "decentralized", with computing power scattered all over the world. However, contrary to decentralization, the mine pool is absolutely centralized, and more and more mining machines are connected to the mine pool
on January 18, 2018, Emin Yun silash, a computer professor at Cornell University, and other five people co authored a paper pointing out that there is an implicit power structure behind bitcoin and Ethereum, the two major digital currencies, and mining is too centralized, in which 50% of bitcoin's computing power is controlled by the four major mines
In fact, this problem has always existed. Four years ago, the founder of Ethereum, vtalik, noticed this problem when he wrote Ethereum white paper. He wrote: "this problem can be said to be very serious. At the time of writing this article, the two largest mines indirectly controlled about 50% of the computing power of the whole network." Up to now, this problem has not been solved. An early translator of the Ethereum white paper told the Southern Weekend reporter, "this is not a technical problem, but a human problem."5
recessive power structure
in the mining circle, the top of the food chain is mining machinery manufacturers. At present, the three recognized mining machinery manufacturers are located in China. Through the proction and sales of mining machines, they get a lot of profits. At the same time, they also set foot in the construction of mines and pools, and have the right to speak in the whole coin circle
ant mining pool is one of the top two large mining pools in the world, and its computing power accounts for 17% of the total network computing power. However, according to instrial and commercial data, it was founded by bitmainland; Several investors of Jianan Yun are also investors of Hangzhou mining Pool Technology Co., Ltd., which has its own mining pool hash and mining platform, but the mining pool has ceased operation at the end of 2017
Yibang communications has set up three blockchain companies in Hohhot, Wuhai and Zhundong Economic Development Zone in Inner Mongolia. A salesperson of Yibang communications told reporters at Nanfang Weekend that they have mines and mining businesses in these three places, but these mines have been operating at full capacity, and there is no machine space to host new mining machines"we are building a new mine in Irkutsk, Russia, where electricity charges are much lower and new mining machines can be hosted there." The source said
above the mining machinery manufacturers, it is the harvest of chip giants“ The core technology of mining machinery lies in the chip. Whoever has the chip can proce more mining machinery. " Ding Yang told reporters at Nanfang Weekend that the chips are mainly in the hands of several giant manufacturers, such as TSMC, NVIDIA, AMD, etc
since 2015, TSMC has always been the largest chip supplier of Jianan Yun. In 2015, the chips purchased by Jianan Yun from TSMC accounted for 69.62% of all the chips purchased by Jianan Yun. Since then, this figure has been maintained at about 60%. Most of the profits of Jia Nan Yun Zhi were made by TSMC
On January 18, 2018, at the presentation meeting of TSMC's fourth quarter financial report, chairman Zhang Zhongmou said that although the mobile business prospect this year is weak, the company's revenue will still grow by 10% - 15%. One of the key factors is the demand for chips e to the continuous and steady development of cryptocurrencyunder the mining machinery manufacturers, there is another power structure. Jianan Yun disclosed this secret in its 2017 prospectus. In the first four months of 2017, four of the top five customers of Jianan Yun were "indivials". According to public information, three of them are well-known "wrists" in the currency circle
Wu Gang, the largest customer, was the first group of miners, and later founded haobtc, which has one of the world's top ten mines; Lin Zhipeng, the second largest customer, is the founder of Xiaoqiang mining machinery. He has been engaged in the proction and sales of mining machinery for a long time. He has been cooperating with Xie Weiqin, the sixth largest customer; Wang Jin, the third largest customer, founded bitbang, a coin circle information websitethese big customers are not simple miners, they all have their own influence in the coin circle. Mechanical operation of the mining machine to bring them income at the same time, also brought the right to speak
according to an insider in bitmainland, most of the big customers in bitmainland are big guys in the currency circle. However, bitmainland officials declined an interview with the Southern Weekend reporter. The company's Public Relations Department responded that it was not convenient to disclose the content because it signed a confidentiality agreement with its customers
"one coin, one villa" wealth myth is still widely spread in the currency circle, and new investors are eager to try. But in fact, a stable power structure has been formed in this small circle, from mining machinery manufacturers to large mine owners, and then to mining pools
most of the new entrants can only make the harvested "leeks"
Definition: through a certain hash algorithm (typically MD5, SHA-1, etc.), a long piece of data is mapped to a short piece of data, which is the hash value of big data. He has such a characteristic that he is the only one. Once big data changes, even a small change, his hash value will also change
on the other hand, since it is DNA, it ensures that the hash values of no two data are exactly the same
the function of hash value: hash value, that is, hash value, is a group of binary values obtained by encrypting the contents of the file. It is mainly used for file verification or signature. Because of this feature, it is often used to determine whether two files are the same
for example, to download a file from the network, just compare the original hash value of the file with the hash value of the downloaded file. If the hash value is the same, it means that the two files are exactly the same, and the file is not damaged ring the download process. If not, it indicates that the downloaded file is different from the original file, and the file is damaged ring the download process
extended data:
hash value is a method to create small digital "fingerprint" from any kind of data. Hash value compresses the message or data into a summary, which makes the data smaller and the data format fixed. This function scrambles the data and creates a new fingerprint called hash values, hash codes, hash sums, or hashes
Thehash value is usually represented by a short string of random letters and numbers. Good hashes rarely have hash conflicts in the input field. In hash table and data processing, it will be more difficult to find database records to distinguish data without suppressing conflicts
typical hash values have very large domains, such as SHA-2, which can accept (2-1) / 8 byte strings. At the same time, the hash value must have a limited range, such as a fixed length bit string. In some cases, the hash value can be designed to have the same size of the definition field and the injectivity between the value fields. The hash value must be irreversible