Ethereum certificate
blockchain service refers to the use of data generated by blockchain to provide a series of operation services such as search query, task submission, etc. based on blockchain
at present, in the field of blockchain, only the block browsers of major public chains can be called blockchain services, as well as some public chain derivative applications: Certificate Deposit Factom, digital identity uport, etc
these applications all have one characteristic, based on the existing public chain, play and strengthen the existing functions of the public chain, so that the public chain can provide better blockchain services for everyone
in other words, if we want to develop a blockchain service-oriented application, we generally mean to develop an application on the public chain
how to build blockchain service
blockchain service refers to the development of public chain applications according to the infrastructure provided by the public chain, and the operation of applications to provide services
for example, smart contract is used to develop public chain applications on Ethereum and run on Ethereum nodes to provide effective services to the public. On bitcoin, we can provide some deposit services with the limited functions of bitcoin
blockchain developers should establish effective channels to collect current blockchain deficiencies and make targeted improvements. This process is called improvement proposals: bitcoin isolation witness (composed of a series of BIPS) is a good example
application layer developers can feed back the problems found in the process of using IP to developers, forming a virtuous circle
and the IP process should not be limited to the technical field, but should go deep into the business layer
blockchain services. JPG
a prediction of public chain infrastructure
most countries in the world support bitcoin payment, but there are still a large number of businesses who do not know how to build bitcoin server wallets. They need to spend a lot of effort to study the deployment and even optimization of public chain wallets, but they do not even have enough technicians to deploy and configure them. On the other hand, leveldb, the official version of bitcoin / Ethereum / metaworld wallet, is actually very unfriendly to the server and is not suitable for the server application at all
a large technology platform should focus on optimizing all kinds of wallets and turning them into a stable and scalable version of the server, which is far more useful than providing blockchain technology stack
it is hoped that in the near future there will be a cloud computing platform to provide bitcoin / Ethereum / Yuanjie and other public chain full node services, and users only need to pay to use them
the next development direction of the public chain in the future is definitely light wallet (mobile terminal) technology, offline payment technology, public chain application development, cloud computing platform to provide simple and easy-to-use public chain full node instance service, exclusive full node service that every ordinary person can buy, using light payment / offline payment and other means to separate the master and public private key pairs, The light wallet provides transaction signature, and the whole node is only responsible for verifying and sending transactions, so as to achieve a perfect user level proct.
POW: full name of proof of work
pos: proof of stake
both of them are the consensus mechanism of blockchain and the bookkeeping method of digital currency
the difference is:
1. POW mechanism: workload proof mechanism, that is, the proof of workload, is the requirement that must be met when generating a new transaction information (that is, a new block) to be added to the blockchain. In the blockchain network based on workload proof mechanism, the ability of nodes to obtain the correct numerical solution to generate blocks by calculating the numerical solution of random hash hash is the specific performance of node computing power
POS mechanism: the proof of rights and interests requires the certifier to provide a certain amount of ownership of cryptocurrency. The operation mode of the proof of rights and interests mechanism is that when creating a new block, the miners need to create a "currency right" transaction, and the transaction will send some coins to the miners themselves according to the preset proportion. According to the proportion and time of token owned by each node, the equity proof mechanism reces the mining difficulty of nodes proportionally according to the algorithm, so as to speed up the speed of searching for random numbersextended materials:
the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's ideas, the open source software and the P2P network on it were designed and released. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
unlike most 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 uses the design of cryptography to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction
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. It is essentially 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 about bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block
if such technology wants to be put into application, the biggest problem is the "Impossible Triangle problem"
that is, scalability, decentralization and security cannot be achieved at the same time, and only two of them can be achieved
most of the existing public chain projects in the market are difficult to put into use on a large scale
Ten instry application scenarios of blockchain are listed on Oracle's website, including finance, proction, ecation, media, entertainment, government, retail business, health, medical care, supply chain, insurance and public utilities. Is it very tall? But what I want to say is that these application scenarios, in front of real high-energy blockchain applications, can only hide in the corner and shiver
now the real high-energy application scenario of blockchain is Ponzi application, commonly known as "Ponzi scheme". It is a smart contract type Qianbao, a blockchain game for rolling in and out of money, an ICO for trading, and a global pension platform
Ponzi scheme is one of the oldest application scenarios of our human beings. After Internet plus, the Ponzi scheme has upgraded the Internet + "Internet plus Ponzi scheme". The Internet enabled the Ponzi scheme, so there was an event similar to the 10 billion level of Qianbao. Before the Internet era, there were few Ponzi schemes on such a large scale. They were enabled through the Internet, and paid through mobile app. Finally, they rolled for several years and reached the 10 billion level
the Internet has broken the geographical restrictions, physical restrictions, capital flow restrictions and communication restrictions. As long as you have a mobile phone, you can play Qianbao app. Everyone participates in it, everyone gets into the money, and everyone gives out the money. According to the data of the people involved, it has reached the level of one million. Relatively speaking, the online pyramid scheme (Ponzi scheme 1.0), which still stays on the top of the list, has meetings every day, can't stop brainwashing, and uses violence and illegal means. It's simple and weak. With the rise of blockchain technology, the Ponzi scheme enabled by "blockchain +" can no longer be described as adding wings like a tiger. It is like a chicken changing into a tiger. Like the Internet, the "block chaining +" technology is a solid application to enhance the application scenario. Ponzi's fraud is further upgraded in the two generation of the Internet plus, because of the major improvement and improvement of the scene, turning into Ponzi scheme 3, whose characteristics are mainly in the following aspects:
1, centralization and no summit. The smart contract of blockchain runs automatically, and it does not need human intervention, nor can it be interrupted by human. Code rules are dead and cannot be tampered with. In terms of scene improvement, it solves the biggest pain point of Ponzi scheme for thousands of years, that is, the problem of head running away. Because the head is a program and code, the program of blockchain can exist forever, and no one can delete it. I think this is the biggest breakthrough. This virtual leader is always there. He can't run away, he can't run, he can't change. The rules will never change. He will stick to the Ponzi line for 100 years, 1000 years and 10000 years. It may be said that smart contracts can be iterated, and they can also be manipulated to leave a back door. Yes, but it can be done without iteration. Even if iteration is transparent and visible, it can be seen at a glance with a back door. This is the characteristic of the blockchain smart contract. If you cheat on it, you will get out a under the teacher's eyes. No one will participate in such a smart contract when it is online. Therefore, after technical review and verification, there is no backdoor, fair rules and irreversible smart contract, which can be realized by using blockchain technology. Such reliability, once verified, will never change. This is the certainty of the smart contract. A program or a character's code will not change. It will run one million times and one trillion times, and the result will be consistent and certain
2. The process was transparent. The number, address, account number, amount and time of deposit; Number, address, account number, amount and time of payment; All visible. Blockchain has a public ledger function, which can be viewed by everyone in the world, and the ledger data viewed by everyone is completely consistent. Why does Qianbao burst? Because we can't see his background account, how much money he goes in and how much money he comes out every day, and the details of each transaction. In this way, you can see the assessment of cashing ability before you pay in, and the assessment result is absolutely certain, that is, it will not change after you pay in
3. Complete anonymization. If you've ever heard of zero proof of knowledge. This part can be skipped. In short, some of the things we used to have in the mathematical knowledge base did not have application scenarios after many inventions. Later, it was found that it was easy to use these knowledge for anonymization. The cryptography technology in the blockchain can achieve identity hiding. As we all know, Zhihu can't achieve anonymity in a real sense in terms of technical structure, and blockchain can
The rules are open and fair to all. One yuan in gold, ten yuan in rebate. Everyone is the same rule. It will never change. If you pay one yuan, go to the front and pay for it, then the back will pay for it, and then pay for it. Fair, right? I have reflected on this many times, and I think it is fair5. Sustainable iteration. In the low-level Ponzi scheme, the leader, proct designer, benefit distributor and benefit receiver are often four in one, while the blockchain Ponzi scheme can completely logically separate the four roles. Achieve sustainable iteration. Through collaboration based on socialization, these projects can be iterated on forever. There are now 400 senior engineers who are developing around bitcoin and constantly updating the code. These people can not know anyone. As long as the application is valuable, they can continue to iterate. Which centralized project can be achieved? Even bat level companies can't employ so many professionals scattered around the world. This kind of social iteration is not affected by the changes of a specific person or organization
"blockchain" enabled Ponzi scheme uses different range of blockchain technology, because the technology in this field is still constantly updated, and the application of smart contract has only increased in the past two years. The earliest application of blockchain is bitcoin. Some people think that bitcoin itself has the characteristics of Ponzi scheme. In 2013, I wrote a reply and implicitly pointed out that this new type of Ponzi scheme will have great lethality, because it has the characteristics of no head, open account book, no running away, open and fair rules. Later, I also found that many people around me like Ponzi scheme much more than blockchain technology. As soon as I hear that bitcoin is not a Ponzi scheme, before I start talking about blockchain technology, I usually walk away in silence. On the contrary, you tell him it's a Ponzi scheme, and then they will ask, where can I buy it? Of course, there is a lot of controversy about whether bitcoin is a Ponzi scheme, because the practical application scenarios of bitcoin have been expanding
in the ICO boom, there are a lot of air coins, such as the bogus Ponzi scheme, which has no application scenarios. The buyers probably know that these air coins are Ponzi schemes, but they buy them because the packaging is good. It is estimated that there are hundreds or thousands of such air coins. The scope of the case is all over the world, and the amount involved is more than 10 billion. These ICOS use smart contracts for subscription and distribution, and then circulate in the secondary market by themselves. In this case, there is no guarantee that the money will be paid out, and some people will lose all their money. Many people, blockchain professionals, have always wanted to draw a clear line with these applications, because although these air coins use part of the blockchain technology, they are still a centralized organization or indivial behind them. There are few network nodes, and users directly converge to a certain organization or indivial when they are paid (so they will be swept away), but there is no doubt that, Air money still uses blockchain to make money and raise funds, which solves part of the problem of running away and improves the scope and communication ability of Ponzi scheme. This is an objective situation
and from this year, with the development of technology, the Ponzi scheme, which uses smart contracts to achieve more decentralization, began to surface. Smart contract locking is used for fund in and fund out to complete a complete closed loop of fund in, fund subscription and fund out. It can already be a very pure blockchain application. Some blockchain games can freely admit that they are a Ponzi game after their release. He said: you see, the rules are transparent, the code is visible, the gold entry contract is locked, they can't run away, no one intervenes, and the gold is automatically paid. Early play, early gain. This is a key breakthrough. It's a way to publicly admit that you are a Ponzi scheme, which can't be done by Ponzi scheme 1.0 and Ponzi scheme 2.0 before. Great. It's simple and rough
this solves the major obstacles in the promotion process of Ponzi scheme, which used to rely on brainwashing, but now it depends on code. You see, "this program doesn't run on its own. There's no back door in it, right? Is the leader gone? The capture of Nakamoto does not affect the continued implementation of the program, does it Therefore, the first batch of blockchain Ponzi scams are hooked by code farmers who can understand the code, and then these code farmers stand up again and say that after technical verification, it is really such an effect, driving other people who do not read the code to join
in addition to realizing the Ponzi scheme application scenarios of entertainment, gambling and fraud, blockchain also has the opportunity to make a big show in the Ponzi scheme application scenarios involving the national economy and the people's livelihood and public utilities, which can even greatly enhance people's sense of gain and happiness, and actually improve people's life. For example, the application of national or global public pension platform based on blockchain can solve several major drawbacks of pension: fund misappropriation. The account book is open, the funds are not centralized and locked, and no one can unlock it, except the recipients who meet the rules can pay out the money. There is no possibility of misappropriation
2. Inflation. The current pension system adjusts the coefficient every year according to a series of complex algorithms such as inflation. After adjustment, the recipients are often dissatisfied because the total amount has increased, but the purchasing power has decreased. Using the feature that virtual currency can't be issued, we can control the inflation rate and ensure that we get real money3. Unpredictable problems. It is very difficult for us to predict the pension payment after 30 years, and we can predict it in advance through smart contract. Stimulate the enthusiasm of paying
4. Policy loopholes and fairness. There will be unfairness in the diversification of groups that any pension policy faces. Everyone wants to pay less and get more, pay later and raise earlier. The transparency of blockchain is refined to each account, rather than a set of general policies to plug the loopholes in the implementation process. Everyone is the same, pay more, pay earlier, pay earlier. It can even be inherited and never lostthis has greatly reced the burden and cost of the state's pension management. What the existing pension system can do, after using the blockchain technology, can still be done, such as the state subsidies, just pay money into the contract, lock it in, there will be no fake, such as compulsory payment, and every record is real and traceable. In a word, all the existing systems and rules can be linked to the chain. On the basis of not affecting the existing effect, the efficiency and output level are improved, and fairness is guaranteed. Moreover, because the cost of the huge management system is reced, the absolute number that everyone can get may be increased by a large part. This has played a real effect on improving people's lives, and also has a positive effect
blockchain developers should establish effective channels to collect the deficiencies of the current blockchain and make targeted improvements. This process is called improvement proposals: bitcoin isolation witness (composed of a series of BIPS) is a good example. Application layer developers can use IP process to feed back the problems found in the use process to developers, forming a virtuous circle. And IP process should not be limited to the technical field, but should go deep into the business layer
the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system.
coinbase transaction is a special transaction that generates bitcoin "out of thin air". Only miners can write this kind of transaction, and the number of generated bitcoin is limited by rules (new currency reced by half for every 210000 blocks + transaction fee for this block)
however, the rules do not stipulate that the miner must take away all the rewards that can be taken, and can choose not to take them
therefore, a mine pool connected with the RSK side chain has made a bug before, forgetting to take away the reward and occupying a pit in a block for nothing, which is equivalent to destroying the corresponding amount of bitcoin, making the total amount of bitcoin decrease a little bit permanently
in addition, to spend a bitcoin, you only need to specify the transaction ID and output serial number
as like as two peas in multiple blocks repeatedly write identical coinbase transactions, the transaction ID is also repeated.
therefore, this kind of situation also occupies the pit of a block in vain, and permanently destroys the corresponding amount of bitcoin
it seems to me that this is still a security vulnerability, so the new version of bitcoin software later banned the writing of repeated coinbase transactions. But until now, there has been no ban on miners not getting their e rewards
generally speaking, a coin is controlled by a private key. If a coin is transferred to an address where no one knows the private key, it will be destroyed
if the owner does a good job in security, and the private key is not disclosed and cannot be guessed, but he accidentally loses the private key, it is equivalent to destroying all the coins he owns
there are only some special circumstances that require intentional destruction of coins
one is irreversibly converted into another kind of currency, such as the contract currency XCP attached to bitcoin and wormhole cash WHC attached to BCH
the second is to save certificates and data on the chain, such as the time stamp: panbiao.com/2013/08 /
and the crowd funding of the original Ethereum founding team: zhuanlan.hu.com/p/29
the private key is essentially a big number. Whoever knows this number can control the currency on the corresponding address. So the private key must be generated with reliable random number, otherwise it may be guessed and stolen
compared with the token, the address is the hash of the public key. There is no way to judge whether an address has a corresponding public key and private key (even if the public key is known, the corresponding private key cannot be known). Therefore, even if it is explicitly the address of "burned" token, the system does not prohibit the transfer in
strictly speaking, what locks the currency is a small program (script). This program takes the input as the public key and digital signature. First, check whether the public key hash is consistent, and then check whether the digital signature is valid. If it is valid, it will be verified and transfer is allowed; Otherwise, it will be judged that the transaction is illegal and refuse to package into the chain
it is the whole node software that explains and executes this program. It can be said that the software code of the whole node specifically defines a coin
however, the current situation is very embarrassing. Most miners do not run the whole node, only a few mines are running. The vast majority of users do not run the whole node, even if they run the whole node, they can only perform verification, no computing power, no block.