Blockchain is a tamper proof shared digital distributed ledger that records transactions in public or private peer-to-peer networks. Distributed ledgers are distributed to all member nodes in the network. The sequential chain of blocks of encrypted hash links is used to record the history of asset exchange between peers in the network.
Blockchain is widely known from bitcoin, but blockchain is not bitcoin, and blockchain is only the underlying technical foundation of bitcoin. Bitcoin can be seen as a byproduct of blockchain.
This paper does not introduce the speculation of currency. There are risks in the currency circle, so it is necessary to be cautious.
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I think the technical personnel should calm down and concentrate on the technology, and watch the flowers bloom and fall in front of the court, and the clouds will roll around the sky!
If you have to ask me my opinion on the currency circle, I think that after reading all my articles, you will find that virtual currency is such a thing. It is just a pile of numbers. If you think it has value, it has value. If you think it is useless, it is just a pile of air.
In fact, the underlying technology of blockchain is not complex, and it is not a new technology. However, when so many technologies are put together, a strong catalytic effect is generated, and the blockchain is born.
The most important technology components of blockchain are cryptography and distributed system. By using consensus mechanism and smart contract in distributed system, a powerful blockchain system is finally produced.
Conclusion: the essence of blockchain is bookkeeping!
What is blockchain
Some students have asked, but they still don’t understand what blockchain is after so much talk. Next, we will use an example to illustrate vividly. This example is pure fiction. If there is any similarity, it is a coincidence
It is said that the annual Huashan sword debate is coming again. Dongxie, Xidu, Nandi, Beijiao, zhongshentong and Guo Xiaoxia, a new comer, are ready to go back and forth in Huashan Mountain.
Then the problem comes. Eating meat and drinking wine need funds. The six people discussed and decided to pay 500 Wen for this activity. In order to facilitate the management of the use of funds, they chose honest and honest Guo Xiaoxia as the bookkeeper of this activity, and Guo Xiaoxia is fully responsible for maintaining the records of the account books.
This is what is now centralized book system. Everything Guo Xiaoxia has the final say, though Guo Xiaoxia is honest and reliable, but it seems that he has missed something.
It’s time for monthly review again. Guo Xiaoxia lists the consumption records of this month and sends them to you. The Western poison looked at the bill and disagreed, because the bill recorded that it cost 20 Wen to enter and leave yicuige at one time. The company said he had never been there, but the bill was the same, and 20 Wen was deducted from his account.
Xidu thinks that it must be Guo Xiaoxia who tried to harm him, and deliberately made a mistake in the account book. However, he had no evidence, so he had to ask for help from Huang Xiaorong, Guo Xiaoxia’s wife.
Huang Xiaorong thought about it and found a solution. Well, each of the six people keeps an account book. As long as someone consumes, they should inform other people and keep accounts together. In this way, there is no problem of tampering with records that may occur in one person’s bookkeeping. This is called a distributed ledger, because the ledger is one record after another, sorted by time, so it is also known as blockchain.
After a period of time, the problem appeared again, because everyone thought that someone would come to the account, and then everyone did not keep the account, resulting in the loss of some records. Huang Xiaorong also came up with an idea. First, the bookkeeper can get a reward of 1 Wen. Through such a reward mechanism, everyone can be encouraged to keep accounts. This mechanism is called mining.
In order to ensure that the accounts recorded in the account books are true and accurate, Huang Xiaorong assigned them a secret code to verify whether the consumption was made by them. This is called cryptography in the blockchain.
However, the problem is not over. If more than one person keeps accounts at the same time and remembers the accounts differently, it will lead to the problem of inconsistent data in the distributed ledger. The solution to this problem is called consensus mechanism. There are many kinds of consensus mechanisms. For example, whoever remembers faster and more will use them. This consensus mechanism is called pow. Another example is that according to who has the most money left, he will be selected to account. This is called POS.
Six people think that if the account book to the 100th time, need to celebrate, to buy a roast lamb chops or something. We also write this logic in the ledger, which is called smart contract.
One day, the Western drug company wants to modify its account books and historical records, but the other five people do not agree. This is called tamper proof mechanism.
If the bookkeeping authority of this chain is extended to the whole Wulin, anyone can participate in bookkeeping, which is called public chain.
If only these six people can keep accounts, it is called private chain.
Guo Xiaoxia’s master, the seven swordsmen in the south of the Yangtze River, heard that he had also built a chain to connect with the five unique links, which is called cross chain operation.
Xidu told the world that he would invite friends from all over the world to build a public chain, saying how promising the chain is, which is called endorsement.
Xidu said that the reward for mining on this public chain is a leaf (with my signature). These leaves are very valuable, and the maximum number is 1000. After digging, there will be no more. This is called issuing money.
However, the chain of Western medicine has not been officially established, and it began to sell leaves in advance, which is called ICO.
Seeing that the big guys are issuing coins, Qiu Qianchi has also issued coins. The Western drug boss despises Qiu Qianchi and calls his coins Shanzhai coins.
So everyone began to sell leaves… No one did anything, and finally ICO got the real money and ran away.
So many examples. If anyone doesn’t understand what blockchain is, please pay attention to me and send me a message! I will teach you hand in hand. I will never give up until I get there.
Blockchain is not what
Remember what I said, the essence of blockchain is just a distributed ledger, which is used to store data. If it is more advanced, it may also contain smart contracts, that is, under certain conditions, certain records will be changed.
There is no essential difference between it and database. Bookkeeping is the real role of blockchain.
Blockchain is not a silver bullet, it is just a means of accounting. So when you see those counterfeit coins boasting of their own projects, you should consider the risks.
What kind of nano currency, space currency, etc., can you transform nanotechnology and let satellites go to the sky in a different way?
What’s more, do you think that the use of blockchain will change the social order and rules? What the hell?
The foundation of blockchain: Cryptography
Cryptography is the foundation of the foundation of blockchain. Without cryptography, there will be no blockchain.
Cryptography is the security guarantee in the blockchain world. How to prevent key loss, how to ensure the security of the transaction, how to verify the correctness of the transaction and so on are all the things that cryptography should do.
The following is my summary on Cryptography:
- Consistent hash algorithm
- Witch attack and its prevention
- HMAC algorithm and its application
- Mac attacks and defects
- One time codebook – a password that will never be cracked
- DES algorithm
- AES algorithm
- Block cipher and mode
- Public key private key
- Detailed explanation of RSA algorithm
- Man in the middle attack
- Hybrid cryptosystem
- One-way hash function
- digital signature
- Read the certificate in cryptography
- Key details
- Diffie Hellman: a more secure key generation method
- Password based password (PBE)
- An article gives you a thorough understanding of SSL / TLS protocol
The foundation of blockchain: distributed system and consensus mechanism
If cryptography is the key of blockchain, then distributed system is the cornerstone of blockchain, and consensus mechanism is the concrete to ensure the stability of blockchain cornerstone.
The following are articles on distributed systems and consensus mechanisms:
- Understanding distributed consistency: raft protocol
- Understanding distributed consistency: basic Paxos of Paxos protocol
- Understanding distributed consistency: multi Paxos of Paxos protocol
- Understanding distributed consistency: cheap Paxos & fast Paxos of Paxos protocol
- Understanding distributed consistency: generalized Paxos & Byzantine Paxos
- Understanding distributed consistency: Byzantine fault tolerance and pbft
Hyperledger is an open source work aimed at promoting cross industry blockchain technology for enterprises to use. This is a global collaboration led by Linux foundation, which includes leaders in finance, banking, Internet of things, supply chain, manufacturing and technology. These 183 different members and nine ongoing projects (including hyperledger fabric) work together to create an open, standardized, enterprise class distributed ledger framework and code base.
Hyperledger is actually made up of many projects
Hyperledger fabric framework supports distributed and distributed ledger solutions on licensed networks, and members understand each other and are suitable for a wide range of industries. Its modular architecture maximizes the confidentiality, flexibility and flexibility of blockchain solutions.
Here’s an article about super books:
- Introduction to distributed ledger
- Hyperledger fabric Basics
- Six characteristics of fabric
- Develop your first fabric smart contract with IBM blockchain platform extension
- Running fabric in IBM cloud
- Using vscode to connect to the IBM cloud blockchain network
Ethereum is a public chain platform developed by the programmer vitalik buterin on the basis of bitcoin. It is called the second generation cryptocurrency and decentralized application platform.
Ethereum creatively puts forward the concept of smart contract, which expands and enriches people’s imagination.
With the smart contract, Ethereum will also have the wings to take off, various dapps have emerged, and Ethereum’s most famous is to issue token in ICO.
Why are so many people issuing tokens on Ethereum? Because it’s too easy to issue tokens on Ethereum.
How simple is it? If people who can’t write programs can issue tokens, it seems that they can’t, which is not enough to reflect the simplicity of Ethereum. Let’s put it this way: Auntie can issue tokens, you will understand.
Define the total number of a token, such as 1000000 billion. It’s created with a little mouse.
The next routine is to build an official website, build a forum, attract popularity, find people to endorse, blow how powerful this project is and how it has a prospect. And then you can ICO.
I still remember a project I once saw, but I can’t remember its specific name. It seems to be called space coin. It makes it a tall building. It seems that with this coin, you can travel in space and travel in space.
I don’t know why so many people believe it!
I make complaints about it for a long time. What I want to say here is that the Ethernet is really another important work for block chain after bitcoin, especially the concept of intelligent contract is widely applied.
The following is my article on Ethereum, which is not a large number at present. I will add the following:
- ERC20 Short Address Attack
- Introduction to bytecode and opcode of solidity
Libra is a blockchain project launched by Facebook. Its mission is to build a simple, borderless currency and financial infrastructure for billions of people.
Facebook believes that traditional financial services are too far away from the poor, and that they are charged expensive and unpredictable fees. There are still 1.7 billion adults worldwide who have never been exposed to the financial system, although one billion of them have mobile phones and 500 million of them have access to the Internet.
Facebook hopes to achieve the goal of Inclusive Finance by virtue of its unique financial characteristics with blockchain.
Facebook hopes to create an open, immediate and low-cost global monetary and financial infrastructure. The combination of the two realizes the “money Internet”.
In fact, there is a certain distance between the concrete implementation of Libra and the decentralization, anonymity and openness of the blockchain, so Libra cannot be regarded as a pure blockchain.
Here are my articles on Libra:
- Interpretation of Libra white paper
- The key concepts of Libra protocol
- The life cycle of transaction
- Libra tutorial 1: how to use Libra testnet
- Here comes your favorite move language
- Libra tutorial 1: running custom move modules
- The logical data model of Libra protocol
- Libra tutorial 1: executing transactions
- Libra tutorial 1: data structure and storage
- Features and examples of move language
Bitcoin is the first and most successful application of blockchain. Through bitcoin, we begin to understand blockchain.
The content of this section will be supplemented by me later.
This article is a collection of blockchain articles, which will be updated continuously. I hope you can enjoy it. Students in need can pay attention to and leave a message, I will try my best to reply, thank you!
The author of this article: what about the flybean program
Link to this article: http://www.flydean.com/blockchain/
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