Blockchain Baizhan
Since 2017, the concept of blockchain, which has been popular all over the society and the world, is still heating up, attracting people and social funds; Boost bitcoin, as well as similar network "encrypted digital currency" (such as ether coin, Wright coin, etc.) price rise, created a lot of "overnight rich" myth. The argument that digital currency and blockchain will subvert tradition and profoundly change the world is constantly rising. The start-up and development of blockchain seems to be coming like a roaring sea, but it is more and more concentrated in coin making and speculation, and more and more trapped in the thinking and paradigm of "bitcoin blockchain" of mining and coin making
in the case that bitcoin must be exchanged with fiat money and must join the network trading platform and other auxiliary links in order to play a greater function, the characteristics of bitcoin blockchain such as area center and disintermediation may have serious problems. In the real world, if the transfer of monetary assets is operated through the bitcoin blockchain system, it will actually increase the intermediary link rather than disintermediation. Moreover, because the bitcoin system is highly anonymous and deliberately evades supervision, it is difficult to fully meet the requirements of anti money laundering and anti-terrorism transportation. On the contrary, many new serious problems may arise, Many arguments about bitcoin and blockchain are difficult to hold
those unseen pain points
the so-called labels of bitcoin blockchain, such as "decentralization", "democracy, equality and freedom", can not stand scrutiny; The truth is that if it puts too much emphasis on "decentralization", it will affect efficiency; Bitcoin has not yet become a real currency; The ICO type fund-raising method is not concive to the development of blockchain... But when people enthusiastically pursue blockchain like faith, they can not see these "pain points":
first, bitcoin blockchain is difficult to build a decentralized, democratic and equal society
bitcoin blockchain system envisages the establishment of an equal and democratic world for all participants, but in fact, the core team of coding maintenance and the main forces involved in mining and operation are not so equal and democratic. Due to the influence of computer computing power, the mining and acquisition of bitcoin are not equal as advertised. As a result of competition, the opportunities of mining and acquiring bitcoin are more and more concentrated on a small number of mining pools or nodes with powerful computing power. However, more and more people are involved in mining, consuming resources, but they may not be able to obtain bitcoin. This makes bitcoin more occupied by a few people, and will enhance its voice or influence on the adjustment of network rules
secondly, there are strict conditions for bitcoin blockchain to "de trust" and "de mediate" point-to-point transactions
Why is the Internet era coming to an end and the blockchain era coming
Once the
blockchain develops, it will burst out more innovation. As the first proct of blockchain, bitcoin has proced many innovations since its birth. For example, small cross-border payment, recording transfer transactions between currencies, recording various stocks, registering housing property rights, recording program codes, etc.
the steam age liberates social proctivity, the electrical age enlivens social cooperation ability, the Internet age connects the world, and the blockchain era will let us truly realize freedom
Share from DTV: how does the blockchain of DTV make profits in the end:
1. Build a blockchain ecosystem
Why do start-ups join in blockchain public chain projects one after another? Because it's a great opportunity. Any enterprise has the opportunity to create an ecosystem that subverts the existing pattern with its own ideas and operations. In this system, the currency designated by the ecosystem owner will circulate
because start-ups hold a certain amount of money and reserve some money for enterprises to dig, and the total amount of money is fixed, the faster the flow speed of the ecosystem is, the greater the demand for money is. More transactions chase less money, and the currency is bound to appreciate, but this idea is based on the fact that the currency is irreplaceable
now many research groups are developing cross chain technology to connect blockchains in different fields, so as to achieve the free circulation of money flow and data flow, and finally go to the exchange
in this case, the impact of a chain of money shortage on the ecosystem may not be as simple as the classical monetary theory, and the money price is likely not to follow the simple relationship between supply and demand. Designers need to think about this from a macroeconomic perspective
this is also the most attractive part of blockchain project: everyone is likely to establish new rules in this new field and become the manager of Qu centralized system. By then, the owners of the blockchain will have the ability to control the economy of the whole field - selling or inhaling digital currency will have a huge impact on the instry
2. Providing services for enterprises
providing services for enterprises is the main profit model of blockchain projects at the present stage, and cloud storage security skeptics are likely to turn to traceable and tamper proof blockchain service providers to seek maximum data security
for example, a blockchain start-up operating a data sharing platform, its main business includes providing data storage and data transaction services for customers, thus charging service fees and handling charges
there are many domestic start-up companies operating such businesses, such as cloud nest, border intelligence, magic chain technology, etc. Each company has excellent technology, but to make a profit, it may have to work hard on the operation
today, Tencent cloud's tbaas has joined this field and can provide services covering finance, supply chain, Internet of things, medical and other fields. It is believed that the competition and expansion of customers will become more difficult in the future
3. Smart contract participates in profit making
smart contract is like a contract that can be executed automatically. The validity of the contract is judged and enforced by machines instead of people. Its essence is still a piece of code, but the traceability and non tampering characteristics of blockchain can ensure that this piece of code runs automatically under the non trust mechanism. Blockchain is the precondition of smart contract operation
in practice, there are many opportunities for profit making through smart contracts, and smart contracts can solve these problems in a non black box way
in the running process of the program, the smart contract performs audit, classification information and other operations, which eliminates the interference of middlemen, and the record will not be artificially damaged, and the font on the file will not be blurred for a long time
but to some extent, the operators of smart contracts themselves become middlemen, and they automatically collect and pay audit fees through smart contracts. This kind of special intermediary service saves a lot of costs for customers, and its essence is realized by improving efficiency
4. Operation of special service driven system
many enterprises have their own exclusive fields in building blockchain community. Take the neurogenomics project led by geneticist church as an example. After enjoying the gene sequencing service provided by neurola, consumers can not pay in the form of legal money, but have to exchange legal money into the token issued by neurola
as more people exchange legal money for this token, nebula will successfully build a blockchain platform with gene data as the core, and after that, it will better carry out precision medical services
generally speaking, this mode relies on the actual technology, makes profits from offline services at the beginning of the project, and converts the legal money in the income into token in the process of making profits. With the progress of the project, the platform can carry out more precision medical services with the help of the data obtained from the start mode, and its profit methods have become diversified, but the whole process will not be separated from the entity
in the whole process of enterprise operation, token is mainly used as incentive, and token appreciation is not a problem that geneticists should consider
The original purpose of project 1CO is to crowdfunding in the market through pre-sale service. In 2013, the early 1CO company appeared in the financial field, and then quickly detonated the entire digital money market, resulting in the rise of speculationhowever, this storm came and went quickly. From 2013 to 2014 alone, many projects died in the speculation or were directly judged as fraud
according to Engadget data, 45.6% of the 902 crowdfunding based digital currencies have failed in 2017
Even so, there are still many survivors. These enterprises (including those that build the ecosystem) attach great importance to the role of token, and the appreciation of token will be calculated as part of the profits In essence, it is similar to an enterprise operating both financial assets (token) and operating assets (service) to manage operating assets to make financial assets profitable. However, if the proportion of "financial assets" is too large, the risk will come uninvited The foundation of sharing economy is to monitor the available resources and corresponding demands in real time and make adjustments to maximize the utilization of resources. For unicorns like airbnb, they have a mature management mode and stable cash flow. They try blockchain because blockchain technology can bring more transparent, more efficient and fairer systemsthis kind of enterprises use blockchain in the way of private chain or alliance chain. They don't need token to participate in circulation, and the nodes don't exist anonymously. They are interested in blockchain technology itself
with the blessing of blockchain technology, the manual input of ID information issued by the government will be transformed into the safe storage and verification of ID issued by the government. Customers and landlords can completely rely on the evaluation content. At the same time, the comments can be traced back to avoid the possibility of negative comments being deleted and the participation of the Navy
the profit model of airbnb and Tencent
The way in which people keep accounts together is also known as "distributed" or "decentralized", because everyone keeps accounts, and the accuracy of the account book is determined by the program algorithm, not by an authoritative organization
this is the blockchain, the core is finished, blockchain is so simple, a common account book
six core algorithms of blockchain Technology:
blockchain core algorithm 1: Byzantine agreement
the story of Byzantine is like this: the Byzantine Empire has great wealth, and the surrounding 10 neighbors have been around for a long time, but the Byzantine walls stand tall and firm, No single neighbor has been able to successfully invade. Any single neighbor's invasion will fail, and at the same time, it may be invaded by other nine neighbors. Byzantine Empire's defense ability is so strong that at least more than half of its ten neighbors attack at the same time before it can be broken. However, if one or several of the neighbors agree to attack together, but betray in the actual process, then the invaders may be annihilated. So each side was careful and could not easily trust its neighbors. This is the question of Byzantine Generals
blockchain core algorithm 2: asymmetric encryption technology
in the above Byzantine agreement, if several of the 10 generals send messages at the same time, it is bound to cause confusion in the system, resulting in different attack time schemes and inconsistent actions. Anyone can send the message of attack, but who will send it? In fact, it only needs to add a cost, that is, only one node can spread information in a period of time. When a node sends a unified attack message, each node must sign and seal to confirm its identity when receiving the message from the initiator
blockchain core algorithm 3: fault tolerance problem
we assume that in this network, messages may be lost, damaged, delayed and sent repeatedly, and the order of receiving is inconsistent with the order of sending. In addition, the behavior of nodes can be arbitrary: they can join or exit the network at any time, they can discard messages, forge messages, stop working and so on, and they may also have all kinds of human or non-human failures. Our algorithm provides fault tolerance for consensus system composed of consensus nodes, which includes both security and availability, and is suitable for any network environment
blockchain core algorithm 4: Paxos algorithm (consistency algorithm)
the problem solved by Paxos algorithm is how a distributed system can reach an agreement on a certain value (decision). A typical scenario is that in a distributed database system, if the initial state of each node is consistent, and each node performs the same operation sequence, then they can finally get a consistent state. In order to ensure that each node executes the same command sequence, it is necessary to execute a "consistency algorithm" on each instruction to ensure that the instructions seen by each node are consistent. A general consistency algorithm can be applied in many scenarios, which is an important problem in distributed computing. There are two models of node communication: shared memory and message passing. Paxos algorithm is a consistency algorithm based on message passing model
blockchain core algorithm 5: consensus mechanism
blockchain consensus algorithm is mainly workload proof and equity proof. Take bitcoin as an example. In fact, from a technical point of view, POW can be regarded as a reusable hashcash, and the generation workload proves to be a random process in probability. When mining a new secret currency and generating a block, the consent of all participants must be obtained, and the miner must obtain the pow work proof of all data in the block. At the same time, miners have to constantly observe and adjust the difficulty of this work, because the requirement for the network is to generate a block every 10 minutes on average
blockchain core algorithm 6: distributed storage is a kind of data storage technology, which uses the disk space of each machine through the network, and forms a virtual storage device with these scattered storage resources, and the data is stored in every corner of the network. Therefore, distributed storage technology does not store complete data in each computer, but stores the data in different computers after cutting. It's like storing 100 eggs, not in the same basket, but separately in different places. The total number is 100. Want to learn more, you can make more use of network search, network search results - small knowledge
imagine that in Byzantine times, there was a rich city-state with all kinds of gold, silver, jewelry, silk and satin, and its Lord Doraemon enjoyed all the luxury and glory. On the outskirts of the city-state, four Byzantine Generals, Daxiong, panghu, Xiaofu and Jingxiang, coveted Doraemon's wealth, so they decided to join hands to capture Doraemon's city-state. According to the strength comparison between the two sides, more than half of the generals must attack at the same time to defeat the enemy, so the winning condition is that at least three of the four can agree on the attack time. What are the odds of the four generals
the answer to this question depends on the cooperation mode of the four people. If it is a centralized system and there is an alliance leader, such as panghu (equivalent to a central server), then there is no doubt about their victory, because it is very easy to reach an agreement on the attack time. As long as panghu calls Daxiong, Xiaofu and Jingxiang to have a meeting to discuss it, Even if we have different opinions, panghu can make a final decision. Now let's go back to the assumption of Byzantine Generals. In a distributed network without trust, what are the odds of four generals winning< br />
?
first of all, e to the lack of trust between the four generals, the possibility of gathering in a small dark room for a conspiracy meeting is ruled out (what if they are kidnapped by panghu in a small dark room?); Secondly, since there is no leader, the opinions of all four people will be equally valued. In this case, the four generals could only negotiate the attack time by sending messages between their camps by messenger. For example, if Daxiong thinks 6 a.m. is a good time to launch an attack, he will send messengers to tell panghu, Xiaofu and Jingxiang their opinions. At the same time, panghu may think it's better to launch a surprise attack at 9 p.m., Xiaofu prefers to launch an attack at 3 p.m., and Jingxiang hopes that it will be 10 a.m., and the three of them will send their own messengers at the same time. In this way, after the first round of communication, each of the four generals had four attack times to choose from, and each of them had to inform the other three of their chosen time in the next round of communication. Because four people make decisions independently, there are 256 possible final choices. Only when more than three people choose the same time can consensus be reached, and there are only 64 such results, that is to say, the probability of reaching consensus is only 1 / 4. This is only the case of four generals. What if the number of generals is 10, 100 or 1000? With a little calculation, we can see that as the number of people increases, the hope of reaching a consensus will become increasingly dim
change the general in the above example into the node in the computer network, the messenger into the communication between nodes, and the attack time into the information that needs to reach a consensus. Then you can understand the dilemma described by the consensus problem. The ability to reach a consensus is self-evident for a payment system. If you remit a sum of money to your family to buy a car and go to the bank the next day for verification, the counter will tell you "about how much money you remit, there are three versions of records in our system". Obviously, you dare not deposit money in such a bank. Before the emergence of bitcoin, the consensus problem is difficult to be solved perfectly. In order to reach a consensus, we need to adopt a centralized system (unless the nodes meet certain conditions), and in order to decentralize the consensus, we can't guarantee it. So how does blockchain technology solve this problem Pay attention to the official account weoption, reply to "block chain", you can view the full text.