区块链stt算法,tpc区块链赚钱快吗

区块链STT算法是一种技术，它可以让用户在区块链上安全地进行交易。STT算法的全称是Secure Transaction Token，它是一种分布式记账技术，可以加密和跟踪交易，以确保交易的安全性。STT算法的特点在于它可以保护用户的隐私，同时也可以确保交易的有效性。

TPC区块链是一种特殊的区块链，它可以提供更高的安全性和性能，以确保交易的安全性和有效性。TPC区块链使用了一种称为“点对点”（P2P）的技术，它可以在两个节点之间进行安全的数据交换，而不需要中央服务器的支持。这种技术的优点是可以更快地处理交易，而且可以更好地保护用户的隐私。

赚钱快，对于TPC区块链来说，是否赚钱快取决于用户的使用方式。TPC区块链提供了一种快速和安全的交易方式，可以让用户更快地完成交易，从而节省时间和金钱。此外，TPC区块链还提供了可以用来提高交易效率的技术，例如智能合约，这些技术可以让用户更快地完成交易，从而节省时间和金钱。

总之，TPC区块链可以提供更快、更安全的交易方式，从而让用户更快地赚钱。它可以提供更高的安全性，并且可以更快地处理交易，从而节省时间和金钱。因此，TPC区块链可以帮助用户更快地赚钱。

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1. Blockchain and edge computing What is blockchain and edge computing analysis

1. Blockchain: Blockchain is a concept of Bitcoin. It uses a block chain data structure to verify and store data, and uses a distributed node consensus algorithm to generate and update data. Utilize cryptographic methods to ensure the security of data transmission and access. It is a new distributed infrastructure and computing method that uses smart contracts composed of automated script codes to program and operate data. It is essentially a disintermediated database.

2. Edge computing: Edge computing is the ability to use an integrated platform of network, device computing, storage, etc., close to the source of data to provide corresponding services nearby. The main feature of edge computing is to provide services based on a regional model near the data end. Since the demand end and the service provider end are very close to each other geographically, it is easier to provide fast and high-quality services, thus gaining popularity from Internet companies. .

3. Edge computing does not actually appear in the past few years. As early as 2003, IBM cooperated with content distribution network CDN and cloud service provider AKAMAI in edge computing. , and edge computing has also begun to cautiously carry out large-scale applications in recent years with the development of blockchain and 5G technology. Since edge computing needs to connect many devices scattered around, it also needs to form a distributed network. This This structure is similar to the decentralization of blockchain, so in many cases, edge computing and blockchain can be well combined.

2. What are the issues that need to be improved in blockchain applications

2018 is the first year of blockchain, but the world’s overall blockchain industry is still in the ascendant stage except for the financial industry. The maturity of the chain industry requires the integration of a series of factors such as technology, market, supervision, and popularity. According to the current development momentum of the blockchain, experts predict that large-scale implementation can be achieved within 3 to 5 years, and the real economy will also have a new development model. What are the issues that need to be improved in the application of blockchain?

Accelerating the implementation of blockchain technology in industrial scenarios still needs to focus on

1. Quick matching of application scenarios.

Use Blockchain technology can effectively solve the pain points of the industry market. In the mainstream B2B transaction mode scenario of the market, it is easier to combine using blockchain technology. If the application scenario meets the conditions of high transaction frequency, fixed transaction scope, insufficient credit, etc., blockchain technology can be easily implemented This scenario. In the future, as the foundation of blockchain technology matures, it will gradually be applied to more transaction models.

2. The technology is further improved.

Blockchain technology is currently perfect Insufficient strength, 51% computing power attack problem, double-spending gap problem, high transaction costs, low TPS throughput, transaction block chain selection problems, excessive energy consumption of the POW consensus mechanism, hacker intrusions and other technical obstacles.

3. The industry mechanism is sound.

Accurately distinguish the relationship between centralization and decentralization. Decentralization means that the entire operating system can operate autonomously under the condition that there is no central organization management. Two strangers can operate at low cost under the conditions of decentralization. , quickly achieve trust and realize transaction facts. However, what is clear is that the ecosystem is not unmanaged. The blockchain is still the information center and requires constant technical role and repeated upgrades. There is a certain centralized mechanism behind it. .

3. Ethereum co-founder said, “Rollup will drive ETH 2.0 to 100k TPS

TPS metric is considered the standard for scalability of any blockchain.< br />
High TPS means a proven network that is capable of scaling and processing user transactions quickly. This part helps position the blockchain as a stable alternative to centralized providers.


Now, with ETH 2.0 Coming soon, the protocol may gradually see over 100,000 TPS, with plans to eventually scale to over a million with the deployment of "shards."

If this happens, public blockchains The popular argument of being slower than VISA will be debunked.

Six-digit TPS is coming to Ethereum

Ethereum’s 26-year-old co-founder Vitalik Buterin said earlier this week Tweeted at the time:

ETH 2.0’s expansion of data will precede general computing, explaining 2-3k TPS with ETH 1.0 as the data layer, and then reaching 100k TPS with ETH 2.0 (Phase 1 ).

— vitalik.eth (@VitalikButerin) June 30, 2020

Buterin noted in an online comment that “the aggregation could grow into the thousands,” It added that shards don’t need to “talk to each other synchronously, enabling synchronous rollups combined with the scalability of shards. ”

On a related Reddit post, Buterin gave the math:

“64 shards * 256 kB per block per shard / 12s slots Time = 1.33 MB/sec. Summary: ~10-12 bytes per tx if packed properly. 1.33m / (10…12) > 100k. ”

He added that the prerequisite for the calculation is that the aggregation “is ready, the phase 1 sharding is ready, and people actuallyThis technology is used. ”

* Ethereum’s TPS as of June 30th

What is a “rollup”?

For starters, a rollup is A layer 2 framework that helps scale the network to multiples of its current level. Aggregation, in its most basic form, stores transaction data on the Ethereum blockchain in a compressed form, while the heavy computation happens off-chain.

One example is Optimistic Rollup, originally proposed by Buterin in 2018. Some teams are also building application-specific zk-Rollups and iterating on the same architectural design to suit their needs .

4. How to calculate the results of Zhilian Blockchain Financial Application Practice Platform

1. Proof of Work (PoW)
Bit proposed by Satoshi Nakamoto in 2009 Bitcoin is the earliest application of blockchain technology. It uses PoW as the consensus algorithm. Its core idea is to obtain accounting rights and Bitcoin rewards through hash computing power competition between nodes. In PoW, different nodes use specific Information competition calculates the solution to a mathematical problem. This mathematical problem is difficult to solve, but it is easy to verify the results. The node that solves the mathematical problem first can create the next block and receive a certain number of currency rewards. Satoshi Nakamoto This mathematical problem is designed using the HashCash[4] mechanism in Bitcoin. This section will take the PoW algorithm used by Bitcoin as an example. The consensus steps of PoW are as follows:
The node collects the data after the previous block is generated. For transactions to be confirmed across the entire network, eligible transactions will be recorded into the transaction memory pool, and then the Merkle root value of the transaction in the memory pool will be updated and calculated, and written into the block header;
In the block header Fill in the block version number, hash value of the previous block, timestamp, current target hash value and random number as shown in Table 1.1;
Table 1.1 Block header information
The random number nonce takes a value between 0 and 232, and the block header information is hashed. When the hash value is less than or equal to the target value, the block is packaged and broadcast, and the accounting is completed after verification by other nodes. ;
If a hash value that meets the requirements cannot be calculated within a certain period of time, repeat step 2. If other nodes complete the calculation during the calculation, restart from step 1.
Bitcoin generation area The average block time is 10 minutes. If you want to maintain this speed, you need to adjust the target value (difficulty) according to the current computing power of the entire network [5]. Difficulty is a description of the difficulty of calculating a block that meets the requirements. , when calculating blocks of the same height, the difficulty of all nodes is the same, which also ensures the fairness of mining. The relationship between difficulty and target value is:
Difficulty value = maximum target value/current target value (1.1)
The biggest goalThe value and the current target value are both 256 bits in length, and the maximum target value is the target value at difficulty 1, which is 2224. Assume that the current difficulty is, the computing power is, the current target value is, and the average calculation time to find a new block is, then
According to the design of Bitcoin, the system will adjust once every 2016 blocks are generated (about 2 weeks) Current target value. The node calculates the adjusted difficulty value according to formula (1.4) based on the actual production time of the first 2016 blocks. If the actual production time is less than 2 weeks, increase the difficulty value; if the actual time production is greater than 2 weeks, decrease the difficulty value. value. According to the longest chain principle, without the need for nodes to synchronize difficulty information, all nodes will get the same difficulty value after a certain period of time.
In a blockchain using PoW, due to network delays and other reasons, when two blocks of the same height are generated close to each other, a fork may occur. That is, different miners have calculated blocks that meet the requirements of a certain height and have been confirmed by nodes close to them. The nodes in the entire network will continue to mine based on the block received first based on the time when the block was received. . In this case, whichever block's subsequent blocks appear first will become longer, and this block will be included in the main chain. Nodes mining on the non-main chain will switch to the main chain to continue mining. .
The PoW consensus algorithm uses computing power as the basis for competition for accounting rights and workload as a guarantee of security. All miners follow the longest chain principle. The newly generated block contains the hash value of the previous block. All existing blocks form a chain. The length of the chain is proportional to the workload. All nodes trust the longest blockchain. If an organization acquires enough computing power, it can launch an attack on the Bitcoin network. When an attacker has enough computing power, he can calculate the latest block first and thus master the longest chain. At this time, most of the blocks on the Bitcoin main chain are generated by it. He can deliberately refuse to confirm certain transactions and carry out double-spend attacks. This will affect the credibility of the Bitcoin network, but this behavior will also causing losses to the attacker. By solving the one-dimensional random walk problem, the relationship between the probability of successful attack by malicious nodes and the computing power can be obtained:
Figure 1.1 The attacker’s computing power and the probability of successful attack
2. Proof of Stake (PoS)
As more and more people participate in Bitcoin mining, many problems of PoW gradually emerge. For example, as the competition for computing power rapidly intensifies, the energy consumed to obtain tokens increases significantly, and the accounting rights gradually increase. "Mining pools" that gather a large amount of computing power are concentrated [6-9]. To this end, researchers are trying to use new mechanisms to replace proof of work. The concept of PoS was mentioned in the earliest Bitcoin project, but was not used due to reasons such as robustness. The earliest application of PoS is PPCoin. PoS proposes the concept of currency age. Coin age is the accumulation of the product of the held tokens and the holding time. The calculation is as shown in formula (1.4). Use currency age competition to replace computing power competition, so that the proof of the blockchain no longer relies solely on workload and can effectively solve the problem.It solves the resource waste problem of PoW.
The holding time is the time since a certain currency was last traded on the network. The longer the currency held by each node, the more rights it has in the network. At the same time, the holder of the currency will also Obtain a certain amount of income based on the age of the currency. In the design of Peercoin, it is not completely separated from the proof of work. Obtaining the accounting rights of the PoS mechanism also requires simple hash calculation:
where proofhash is composed of weight factor, unconsumed output value and current time The fuzzy and hash values ​​obtained also limit the computing power of each node. It can be seen that the currency age is inversely proportional to the difficulty of calculation. In PoS, the security of the blockchain increases as the value of the blockchain increases. Attacks on the blockchain require attackers to accumulate a large amount of currency age, which means they need to hold a large amount of digital currency for a long enough time. This also greatly increases the difficulty of the attack. Compared with PoW, blockchain systems using PoS may face Long Range Attack and Nothing at Stake.
In addition to Peercoin, many coins also use PoS, but they have different methods for allocating accounting rights. For example, Nxt and BlackCion combine the rights owned by nodes and use random algorithms to allocate accounting rights. Ethereum is also gradually adopting PoS instead of PoW.
3. Delegated Proof of Stake (DPoS)
At the beginning of the design of Bitcoin, it was hoped that all mining participants would use CPUs for calculations, and the computing power would match the nodes, so that each node would have enough opportunities to participate. Blockchain decision-making. With the development of technology, a large number of mining machines using GPU, FPGA, ASIC and other technologies have emerged. The computing power is concentrated in the hands of participants with a large number of mining machines, while the opportunities for ordinary miners to participate are greatly reduced.
In a blockchain using DPoS, each node can vote to select representatives based on the share rights it owns. The n nodes in the entire network that participate in the election and receive the most votes gain accounting rights in a predetermined order. Produce blocks in sequence and receive certain rewards for doing so. Representative nodes that succeed in the election need to pay a certain amount of deposit and must ensure online time. If the node that should generate blocks at a certain moment fails to perform its duties, he will be disqualified as a representative, and the system will continue to vote to elect a new representative. to replace him.
All nodes in DPoS can independently choose the objects to vote. The elected representatives are accounted for in order. Compared with PoW and PoS, computing resources are saved. Moreover, there are only a limited number of consensus nodes, and the efficiency is also improved. promote. Moreover, each participating node has the right to vote. When there are enough nodes in the network, the security and decentralization of DPoS are also guaranteed.
4. Practical Byzantine Fault Tolerance Algorithm (PBFT)
In the PBFT algorithm, all nodes run under the same configuration and have one masternode, and other nodes serve as backup nodes. The primary node is responsible for sorting client requests and sending them to the backup node in order. There is the concept of View, and in each view, all nodes process messages normally. But when the backup node detects an exception on the primary node, it will trigger the View Change mechanism to replace the next numbered node as the primary node and enter a new view. The main process in PBFT from the client sending a request to receiving the reply is shown in Figure 4.1 [10] [11]. Information is exchanged between servers three times. The whole process includes the following five stages:
Figure 4.1 PBFT execution process
At present, Byzantine fault-tolerant algorithms represented by PBFT are used by many blockchain projects. In the alliance chain, the PBFT algorithm was first adopted by the Hyper ledger Fabric project. Hyperledger Fabric uses the PBFT consensus algorithm in version 0.6. The authorization and endorsement functions are integrated into the consensus nodes. All nodes are consensus nodes. This design results in an overly heavy burden on the nodes, which has a great impact on TPS and scalability. Impact. Versions after 1.0 have separated the functions of the nodes. The nodes are divided into three endorsement nodes (Endorser), ordering nodes (Orderer) and block nodes (Committer). The functions of the nodes have been separated, which has improved the efficiency to a certain extent. Consensus efficiency.
The Tendermint[12] algorithm used by the Cosmos project combines the PBFT and PoS algorithms, and selects some consensus nodes for BFT consensus through token mortgage. It weakens the asynchronous assumption and incorporates locks on the basis of PBFT. The concept of consensus nodes in a partially synchronized network can reach consensus through two-phase communication. The system can tolerate 1/3 of failed nodes without causing forks. On the basis of Tendermint, Hotstuff [13] integrates the block chain structure of the blockchain with each stage of BFT. In each stage, the signature confirmation of the previous block and the construction of the new block are carried out simultaneously, making the algorithm realize Even simpler, Hotstuff also uses threshold signatures [14] to reduce the message complexity of the algorithm.
5. Paxos and Raft
The consensus algorithm is a set of mechanisms designed to ensure the accuracy and consistency of stored information. In traditional distributed systems, the most commonly used consensus algorithm is the Paxos-based algorithm. After the Byzantine Generals Problem [3] was raised, Lamport proposed the Paxos algorithm in 1990 to solve the system consistency problem under specific conditions. Lamport reorganized and published the Paxos paper [15] in 1998 and conducted a research on Paxos in 2001. was re-briefed [16]. Paxos subsequently dominated the field of consensus algorithms and was adopted by many companies, such as Tencent’sPhxpaxos, Alibaba's X-Paxos, Amazon's AWS's DynamoDB and Google's MegaStore[17], etc. This type of algorithm can quickly complete data synchronization in a distributed system when the number of nodes is limited and relatively trustworthy, while being able to tolerate crash faults. That is to say, in traditional distributed systems, there is no need to consider behaviors such as malicious tampering of data by participating nodes, and only need to be able to tolerate downtime errors on some nodes. However, the Paxos algorithm is too theoretical and is very difficult to understand and implement in engineering. Ongaro et al. published a paper in 2013 proposing the Raft algorithm [18]. Raft has the same effect as Paxos and is more convenient for engineering implementation.
The leader occupies an absolutely dominant position in Raft, and the absolute security of server nodes must be ensured. Once the leader is maliciously controlled, huge losses will be caused. And the transaction volume is limited by the maximum throughput of the node. Currently, many alliance chains use the Raft algorithm to improve consensus efficiency without considering Byzantine fault tolerance.
6. Consensus algorithm combined with VRF
In the existing alliance chain consensus algorithm, if the number of nodes participating in the consensus increases, the communication between nodes will also increase, and the performance of the system will also be affected. If some nodes are selected from many candidate nodes to form a consensus group for consensus and the number of consensus nodes is reduced, the performance of the system can be improved. But this will reduce security, and the higher the proportion of malicious nodes among candidate nodes, the higher the probability that the selected consensus group will not function properly. In order to select a consensus group that can operate normally from the candidate nodes and ensure the high availability of the system, on the one hand, it is necessary to design an appropriate random election algorithm to ensure the randomness of the selection and prevent malicious nodes from attacking the system. On the other hand, it is necessary to increase the proportion of honest nodes among candidate nodes and increase the probability of honest nodes being selected into the consensus group.
Currently, public chains are often based on PoS algorithms. Mortgage tokens increase the entry threshold for consensus nodes, increase the cost of malicious nodes through economic games, and then use random election algorithms among some of the nodes that pass the screening. Randomly select some nodes from qualified candidate nodes for consensus.
Dodis et al. proposed Verifiable Random Functions (VRF) in 1999 [19]. Verifiable random function is an application of zero-knowledge proof, that is, in the public-private key system, the person holding the private key can use the private key and a piece of known information to generate a random number according to specific rules without revealing the private key. Under the premise, the person holding the private key can prove to others the correctness of the random number generation. VRF can be constructed using RSA or elliptic curves. In 2002, Dodis et al. proposed a verifiable random function construction method based on the Diffie-Hellman difficulty problem [20]. Currently, the verifiable random function isIt has applications in both the key transmission field and the blockchain field [21]. The specific process of the verifiable random function is as follows:
In the public chain, VRF has been applied in some projects. VRF is mostly combined with the PoS algorithm. All nodes that want to participate in the consensus pledge certain tokens to become candidate nodes. , and then randomly select some consensus nodes from many candidate nodes through VRF. New nodes in the Zilliqa network must first perform PoW. Existing nodes in the network verify the new node's PoW and authorize it to join the network. The consensus algorithm VBFT designed by the blockchain project Ontology combines VRF, PoS and BFT algorithms. VRF randomly selects consensus nodes among many candidate nodes and determines the order of consensus nodes, which can reduce the impact of malicious forks on the blockchain system. The impact ensures the fairness and randomness of the algorithm. Algorand[22] proposed by Turing Award winner Micali et al. combines PoS and VRF. Nodes can become candidate nodes by pledging tokens, and then select some nodes to form a consensus committee through the non-interactive VRF algorithm, and then this will Some nodes implement a consensus algorithm similar to PBFT and are responsible for rapid verification of transactions. Algorand can ensure the normal operation of the system when the nodes are honest nodes. Ouroboros[23] proposed by Kiayias et al. introduced VRF in the second version Praos[24] to replace pseudo-random numbers to select master nodes in shards. Taking the VRF algorithm used by Algorand and other algorithms as an example, the main process is as follows:
In the VRF designed and used in public chains, the probability of a node being selected as an accounting node is often positively related to the tokens it holds. The consensus node range of the public chain cannot be determined in advance. All nodes that meet the token holding conditions may become consensus nodes. The system needs to select some nodes among the nodes with random number and participation for consensus. Compared with the public chain, the number of nodes participating in the consensus of the alliance chain is limited and the nodes are known. In this case, the nodes of the alliance chain can interact through the known node list, which can effectively prevent possible problems when designing the VRF of the public chain. to the witch attack problem.
7. Formula algorithm combined with sharding technology
Sharding technology is a technology in databases that cuts the data in the database into multiple parts and then stores them in multiple servers. Improve the search performance of the server through distributed storage of data. In blockchain, sharding technology is a mechanism that allocates transactions to multiple consensus groups composed of node subsets for confirmation, and finally aggregates all results for confirmation. Sharding technology already has some applications in blockchain, and many blockchains have designed their own sharding solutions.
Luu et al. proposed the Elastico protocol in 2017, which was the first to apply sharding technology to the blockchain [25]. Elastico first competes to become the accounting node in the network through the PoW algorithm. Then according to the predetermined rulesThen, these nodes are assigned to different shard committees. Each sharding committee internally executes traditional Byzantine fault-tolerant consensus algorithms such as PBFT, and packages and generates transaction sets. After more than one node signs the transaction set, the transaction set is submitted to the consensus committee. After verifying the signatures, the consensus committee finally packages all the transaction sets into blocks and records them on the blockchain.
Elastico verifies the usability of sharding technology in blockchain. Within a certain scale, sharding technology can scale throughput nearly linearly. However, Elastico uses PoW to elect consensus nodes, which also causes the random number generation process and PoW competition for consensus nodes to take too long, resulting in high transaction delays. Moreover, the PBFT algorithm used within each shard has high communication complexity. Latency is also high when the number of nodes in a single shard is high.
Based on Elastico, Kokoris-Kogias et al. proposed OmniLedger [26], which used an encrypted lottery protocol to replace PoW to select validator groups, and then classified the validators into different shards through the RandHound protocol [27]. OmniLedger. OmniLedger still uses the PBFT-based consensus algorithm as the consensus algorithm in sharding [28], and introduces the Atomix protocol to handle cross-shard transactions. The communication complexity between nodes during the consensus process is high. When the number of nodes in a shard increases and cross-shard transactions increase, system TPS will drop significantly.
Wang et al. proposed Monoxide in 2019[29]. Introduced sharding technology into the PoW blockchain system and proposed the Chu ko-nu mining algorithm, which solved the problem of dispersion of computing power caused by sharding, allowing each miner to work on different locations at the same time. Sharding through sharding improves the TPS of PoW without reducing security.

5. How to use blockchain in supply chain finance

In traditional supply chain finance, financing difficulties, high financing costs, and cumbersome financing processes have always been constraints for small, medium and micro enterprises. One of the bottlenecks to becoming bigger and stronger. The bank relies on the core enterprise's ability to control goods and adjust sales. For risk control considerations, the bank is only willing to provide factoring business to upstream suppliers (limited to first-tier suppliers) that have direct accounts payable obligations of the core enterprise, or Provide advance payment or inventory financing to its downstream dealers (first-tier suppliers). This has resulted in the needs of second- and third-tier suppliers/dealers with huge financing needs not being met, and the business volume of supply chain finance being restricted. The lack of timely financing for small and medium-sized enterprises can easily lead to product quality problems. , will harm the entire supply chain system.

To solve these problems, the decentralized, non-tamperable, and distributed ledger characteristics of blockchain technology can be used to create a blockchain supply chain financial platform.

1. Core enterprise signatureSend the receivable voucher to the distributor. After the distributor signs the receipt, it means that a purchase and sales contract has been signed, and the core enterprise delivers the goods.

2. Distributors need financial loans due to financial constraints.

3. The financial institution will transfer the loan amount to the core enterprise after review and approval.

4. The distributor repays the loan and interest after selling the goods

6. Tutorial on getting started with blockchain

However, it is simple and easy to understand There are very few introductory articles. What exactly blockchain is and what makes it special is rarely explained.
Next, I will try to write a best-understood blockchain tutorial. After all, it is not difficult. The core concept is very simple and can be explained clearly in a few sentences. I hope that after reading this article, you will not only understand the blockchain, but also understand what mining is, why mining is getting more and more difficult, and other issues.
It should be noted that I am not an expert in this area. Although I have been paying attention to it for a long time, my detailed understanding of blockchain started at the beginning of this year. You are welcome to correct any errors or inaccuracies in the article.
1. The essence of blockchain
What is blockchain? In a word, it is a special distributed database.
First of all, the main function of blockchain is to store information. Any information that needs to be saved can be written to the blockchain and read from it, so it is a database.
Secondly, anyone can set up a server, join the blockchain network, and become a node. In the world of blockchain, there is no central node. Every node is equal and stores the entire database. You can write/read data to any node, because all nodes will eventually be synchronized to ensure that the blockchain is consistent.
2. The biggest features of blockchain
Distributed databases are not a new invention, and there have been such products on the market for a long time. However, blockchain has a revolutionary feature.
Blockchain has no administrator, it is completely centerless. Other databases have administrators, but blockchain does not. If one wanted to add auditing to the blockchain, it would not be possible because it is designed to prevent the emergence of a central authority.
It is precisely because it is unmanageable that blockchain can be uncontrollable. Otherwise, once big companies and large groups control the management, they will control the entire platform, and other users will have to take orders from them.
However, without an administrator, everyone can write data into it. How can we ensure that the data is trustworthy? What if it is modified by a bad person? Please read on, this is the wonderful thing about blockchain place.
3. Block
Blockchain is composed of blocks. Blocks are much like database records. Every time data is written, a block is created.
Each block contains two parts.
Head: records the characteristic values ​​of the current block
Body: actual data
The block header contains multiple characteristic values ​​of the current block.
Generation time
Actual data (i.e. block body)
The hash of the previous block
...
Here, you need to understand what a hash is, which is necessary to understand the blockchain.
The so-called hashing means that the computer can calculate a characteristic value of the same length for any content. The hash length of the blockchain is 256 bits, which means that no matter what the original content is, a 256-bit binary number will be calculated in the end. And it can be guaranteed that as long as the original content is different, the corresponding hash must be different.
For example, the hash of the string 123 is (hexadecimal), which is 256 bits when converted to binary, and only 123 can get this hash. (Theoretically, it is possible for other strings to get this hash, but the probability is extremely low and can be approximated as impossible.)
Therefore, there are two important inferences.
Corollary 1: The hash of each block is different, and the block can be identified by the hash.
Corollary 2: If the content of the block changes, its hash will definitely change.
4. The non-modifiable nature of Hash
Blocks and hashes have a one-to-one correspondence, and the hash of each block is calculated based on the block header (Head). That is to say, the characteristic values ​​​​of the block header are connected together in order to form a very long string, and then the hash is calculated on this string.
Hash = SHA256 (block header)
The above is the calculation formula of block hash. SHA256 is the hash algorithm of the blockchain. Note that this formula only contains the block header and not the block body. In other words, the hash is uniquely determined by the block header.
As mentioned before, the block header contains a lot of content, including the hash of the current block body. , and the hash of the previous block. This means that if the content of the current block body changes, or the hash of the previous block changes, it will definitely cause the hash of the current block to change.
This point has great significance for blockchain. If someone modifies a block, the hash of the block changes. In order for subsequent blocks to still be connected to it (because the next block contains the hash of the previous block), the person must modify all subsequent blocks in sequence, otherwise the modified block will be removed from the blockchain . Due to the reasons mentioned later, hash calculation is very time-consuming, and it is almost impossible to modify multiple blocks in a short period of time, unless someone controls more than 51% of the computing power of the entire network.
It is through this linkage mechanism that the blockchain ensures its own reliability. Once the data is written, it cannot be tampered with. This is just like history, what happened happened, and it can’t be changed from now on.
Each block is connected to the previous block, which is where the name blockchain comes from.
5. Mining
Since synchronization between nodes must be ensured, the adding speed of new blocks cannot be too fast. Just imagine, you have just synchronized a block and are preparing to generate the next block based on it, but at this time, other nodes have new blocks generated, and you have to give up half of the calculations and thento synchronize. Because each block can only be followed by one block, you can only generate the next block after the latest block. So, you have no choice but to sync as soon as you hear the signal.
So, the inventor of the blockchain, Satoshi Nakamoto (this is a pseudonym, and his true identity is still unknown) deliberately made it difficult to add new blocks. His design is that on average, the entire network can generate a new block every 10 minutes, which is only six per hour.
This output speed is not achieved through commands, but by deliberately setting up massive calculations. In other words, only through an extremely large amount of calculations can the effective hash of the current block be obtained and the new block added to the blockchain. Because the amount of calculation is too large, it cannot be done quickly.
This process is called mining, because the difficulty of calculating a valid hash is like finding a grain of sand that meets the conditions among the sand in the world. The machine that calculates hashes is called a mining machine, and the person who operates the mining machine is called a miner.
6. Difficulty coefficient
After reading this, you may have a question. People say that mining is difficult, but isn’t mining just about using a computer to calculate a hash? This is the strength of computers. How could it be? It becomes very difficult, why can’t it be calculated?
It turns out that not just any hash can be used, only hashes that meet the conditions will be accepted by the blockchain. This condition is particularly harsh, causing most hashes to fail to meet the requirements and must be recalculated.
It turns out that the block header contains a difficulty coefficient (difficulty), which determines the difficulty of calculating the hash. For example, the difficulty coefficient of the 100,000th block is 14484.16236122.
The blockchain protocol stipulates that the target value (target) can be obtained by dividing the difficulty coefficient by a constant. Obviously, the greater the difficulty coefficient, the smaller the target value.
The validity of the hash is closely related to the target value. Only hashes smaller than the target value are valid, otherwise the hash is invalid and must be recalculated. Since the target value is very small, the chance that the hash is smaller than this value is extremely slim, and it may be calculated 1 billion times before it is considered a hit. This is the fundamental reason why mining is so slow.
As mentioned earlier, the hash of the current block is uniquely determined by the block header. If the hash of the same block needs to be calculated repeatedly, it means that the block header must keep changing, otherwise it is impossible to calculate different hashes. All feature values ​​in the block header are fixed. In order to make the block header change, Satoshi Nakamoto deliberately added a random item called Nonce.
Nonce is a random value. The role of the miner is actually to guess the value of Nonce so that the hash of the block header can be smaller than the target value so that it can be written to the blockchain. Nonce is very difficult to guess. At present, we can only use trial and error one by one through exhaustive methods. According to the protocol, Nonce is a 32-bit binary value, which can reach a maximum of 2.147 billion. The Nonce value of the 100,000th block is 274148111, which is understandableSuccessfully, the miner started from 0 and calculated 274 million times before obtaining a valid Nonce value, so that the calculated hash can meet the conditions.
If you are lucky, you may find Nonce in a while. If you are unlucky, you may have calculated it 2.147 billion times without finding the Nonce, that is, it is impossible to calculate a hash that meets the conditions for the current block body. At this time, the protocol allows miners to change the block body and start a new calculation.
7. Dynamic adjustment of difficulty coefficient
As mentioned in the previous section, mining is random, and there is no guarantee that a block will be produced in exactly ten minutes. Sometimes it can be calculated in one minute, and sometimes it may take several hours. No result. Overall, with the improvement of hardware equipment and the increase in the number of mining machines, the computing speed will definitely become faster and faster.
In order to keep the output rate constant at ten minutes, Satoshi Nakamoto also designed a dynamic adjustment mechanism for the difficulty coefficient. He stipulated that the difficulty factor should be adjusted every two weeks (2016 blocks). If the average block generation speed in these two weeks is 9 minutes, it means that it is 10% faster than the legal speed, so the next difficulty factor will be increased by 10%; if the average block generation speed is 11 minutes, it means It is 10% slower than the legal speed, so the difficulty factor of the next step must be lowered by 10%.
The difficulty coefficient is adjusted higher and higher (the target value is getting smaller and smaller), which makes mining more and more difficult.
8. Forks of the blockchain
Even if the blockchain is reliable, there is still an unresolved problem: if two people write data to the blockchain at the same time, that is to say, two people write data to the blockchain at the same time. Blocks join because they are connected to the previous block, forming a fork. Which block should be adopted at this time?
The current rule is that new nodes always adopt the longest blockchain. If there is a fork in the blockchain, it will look at which branch is behind the fork to reach 6 new blocks first (called six confirmations). Based on a block calculation of 10 minutes, it can be confirmed in one hour.
Since the generation speed of new blocks is determined by computing power, this rule means that the branch with the most computing power is the authentic blockchain.
9. Summary
Blockchain, as an unmanaged distributed database, has been running for 8 years since 2009 without major problems. This proves it works.
However, in order to ensure the reliability of data, blockchain also has its own price. The first is efficiency. You have to wait at least ten minutes to write data to the blockchain. All nodes synchronize the data, which requires more time. The second is energy consumption. The generation of blocks requires miners to perform countless meaningless calculations. This is Very energy consuming.
Therefore, the applicable scenarios of blockchain are actually very limited.
There is no management authority that all members trust
The written data does not require real-time use
The benefits of mining can make up for its own costs
If the above conditions cannot be met, then the traditional database is Better solution.
Currently, the largest application of blockchainThe scenario (possibly the only application scenario) is cryptocurrency represented by Bitcoin.

7. 108 knowledge points for getting started with blockchain

1. What is blockchain

Putting the information and representation of multiple transactions The information of the block is packaged together, and the verified package is the block.

Each block stores the hash value of the previous block, creating a relationship between blocks, that is to say, a chain. Together they are called blockchain.

2. What is Bitcoin

The concept of Bitcoin was proposed by Satoshi Nakamoto in 2009, with a total number of 21 million. The Bitcoin chain generates a block approximately every 10 minutes, and this block is mined by miners for 10 minutes. As a reward to miners, a certain number of Bitcoins will be issued to miners, but this certain number is halved every four years. Now it's 12.5. If this continues, all Bitcoins will be available in 2040.

3. What is Ethereum

The biggest difference between Ethereum and Bitcoin is the smart contract. This allows developers to develop and run various applications on it.

4. Distributed ledger

It is a database that is shared, replicated and synchronized among network members. To put it bluntly, all users on the blockchain have accounting functions and the content is consistent, which ensures that the data cannot be tampered with.

5. What is quasi-anonymity?

I believe everyone has a wallet, and the wallet address (a string of characters) used to send transactions is quasi-anonymity.

6． What is open transparency/traceability

The blockchain stores all data from history to the present, anyone can view it, and can also view any data in history.

7. What is tamper-proof

Historical data and current transaction data cannot be tampered with. The data is stored in the block on the chain and has a hash value. If the block information is modified, its hash value will also change, and the hash values ​​of all blocks following it must also be modified to form a new chain. At the same time, the main chain is still conducting transactions to generate blocks. The modified chain must always generate blocks synchronously with the main chain to ensure that the length of the chain is the same. The cost is too high, just to modify a piece of data.

8. What is anti-DDoS attack

DDoS: Hackers control many people’s computers or mobile phones and allow them to access a website at the same time. Since the bandwidth of the server is limited, a large amount of traffic The influx of data may cause the website to fail to function properly, resulting in losses. But the blockchain is distributed, there is no oneIf one node fails, the other nodes will not be affected. Theoretically, if more than 51% of the nodes are attacked, problems will occur.

9. Definition of main chain

Taking Bitcoin as an example, at a certain point in time, a block is mined by two miners at the same time, and then 6 blocks are generated first. The chain of blocks is the main chain

10. Single chain/multi-chain

Single chain refers to the data structure that handles everything on one chain. The core essence of the multi-chain structure is composed of public chain + N sub-chains. There is only one, but in theory there can be countless sub-chains, and each sub-chain can run one or more DAPP systems

11. Public chain/alliance chain/private chain

Public Chain: Everyone can participate in the blockchain

Alliance chain: Only alliance members are allowed to participate in accounting and query

Private chain: Writing and viewing permissions are only controlled by one person In the hands of the organization.

12. Consensus layer, data layer, etc.

There are six overall structures of the blockchain: data layer, network layer, consensus layer, incentive layer, contract layer, and application layer. Data layer: a layer that records data, belonging to the underlying technology; network layer: a structure for building a blockchain network, which determines how users are organized. Consensus layer: Provides a set of rules to allow everyone to reach agreement on the information received and stored. Incentive layer: Design incentive policies to encourage users to participate in the blockchain ecosystem; Contract layer: Generally refers to "smart contracts", which are a set of contract systems that can be automatically executed and written according to their own needs. Application layer: Applications on the blockchain, similar to mobile apps. Former Distributed Storage R&D Center

13. Timestamp

The timestamp refers to January 1, 1970 Day 0 hours 0 minutes 0 seconds 0... The total number of seconds from the current time to now, or the total number of nanoseconds and other very large numbers. Each block is generated with a timestamp indicating when the block was generated.

14． Block/block header/block body

Block is the basic unit of blockchain, and block header and block body are components of blockchain. The information contained in the block header includes the hash of the previous block, the hash of this block, timestamp, etc. The block body is the detailed data in the block.

15. Merkle tree

Merkle tree, also called binary tree, is a data structure for storing data. The bottom layer is the original data contained in all blocks, and the upper layer is each The hash value of a block, the hash value of this layer is combined in pairs to generate a new hash value, forming a new layer, and then upwards layer by layer, until a hash value is generated. Such a structure can be used to quicklyWith a large amount of data, you can quickly find the bottom-level historical data you want without downloading all the data.

16. What is expansion?

The size of a Bitcoin block is about 1M and can save 4,000 transaction records. Expansion means making the block larger so that more data can be stored.

17. What is a chain?

Each block will save the hash of the previous block, creating a relationship between the blocks. This relationship is a chain. Data such as block transaction records and status changes are stored through this chain.

18. Block height

This is not the height mentioned in terms of distance. It refers to the total number of blocks between the block and the first block on the chain. This height indicates which block it is, and is just for identification purposes.

19. Fork

Two blocks were generated at the same time (the transaction information in the block is the same, but the hash value of the block is different), and then in Two chains are forked from these two blocks. Whoever generates 6 blocks from these two links first will be the main chain, and the other chain will be discarded.

20. Ghost Protocol

Mining pools with high computing power can easily generate blocks faster than mining machines with low computing power, resulting in most of the blocks on the blockchain being generated by these mining pools with high computing power. However, the blocks generated by mining machines with low computing power are not stored on the chain because they are slow, and these blocks will be invalid.

The ghost protocol allows blocks that should be invalidated to remain on the chain for a short time, and can also be used as part of the proof of work

. In this way, miners with small computing power will contribute more to the main chain, and large mining pools will not be able to monopolize the confirmation of new blocks.

21. Orphan blocks

As mentioned before, orphan blocks are blocks generated at the same time. One of them forms a chain, and the other does not form a chain. Then this block that does not form a chain is called an orphan block.

22. Uncle block

The orphan block mentioned above, through the ghost protocol, makes it part of the proof of work, then it will not be discarded and will be saved in the main chain superior. This block is the next

23 replay attack

The hacker resends the message that has been sent to the server. Sometimes this can deceive the server into multiple responses.

24. Directed acyclic graph

Also called data set DAG (directed acyclic graph), DAG is an ideal multi-chain data structure.Most of the blockchains mentioned now are single chains, that is, one block is connected to another block, and DAG is multiple blocks connected. The advantage is that several blocks can be generated at the same time, so the network can process a large number of transactions at the same time, and the throughput will definitely increase. However, there are many shortcomings and it is currently in the research stage.

25. What is mining

The mining process is to perform a series of conversions, connections and hash operations on the above six fields, and continue to try them one by one. The random number you are looking for, and finally successfully find a random number that meets the conditions: the value after hashing is smaller than the hash value of the preset difficulty value, then the mining is successful, and the node can broadcast the area to neighboring nodes. block, neighboring nodes receive the block and perform the same operation on the above six fields to verify compliance, and then forward it to other nodes. Other nodes also use the same algorithm to verify. If there are 51% of nodes in the entire network If all verifications are successful, even if this block is truly "mined" successfully, each node will add this block to the end of the previous block, delete the list in the block that is the same as its own record, and resurrect again. the above process. Another thing to mention is that regardless of whether the mining is successful or not, each node will pre-record the reward of 50 Bitcoins and the handling fees of all transactions (total input-total output) in the first item of the transaction list (this is " The most fundamental purpose of "mining" is also the fundamental reason to ensure the long-term stable operation of the blockchain), the output address is the address of this node, but if the mining is unsuccessful, the transaction will be invalidated without any reward. Moreover, this transaction called "production transaction" does not participate in the "mining" calculation.

26. Mining machines/mines

Mining machines are computers with various configurations, and computing power is the biggest difference between them. A place where mining machines are concentrated in one place is a mining farm

27. Mining pool

Miners join together to form a team, and the computer group under this team is a mining pool. Mining rewards are distributed based on your own computing power contribution.

28. Mining difficulty and computing power

Mining difficulty is to ensure that the interval between generating blocks is stable within a certain short time, such as Bitcoin’s 10 minutes.

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Block 1. The computing power is the configuration of the mining machine.

29. Verification

When verification in the blockchain is a confirmation of the legality of the transaction, each node will verify the transaction once when the transaction message is propagated between nodes. Whether the transaction is legal. For example, verify whether the syntax of the transaction is correct, whether the transaction amount is greater than 0, whether the entered transaction amount is reasonable, etc. After passing the verification, it will be packaged and handed over to the miners for mining.

30. Transaction broadcast

The node sends information to other nodes through the network.

31. Mining fees

For the blockchain to work non-stop like a perpetual motion machine, miners need to maintain the system. Therefore, the miners must be given favorable fees to make it sustainable.

32. Transaction confirmation

When a transaction occurs, the block recording the transaction will be confirmed for the first time, and will be confirmed in every area on the chain after the block. Block is reconfirmed: When the number of confirmations reaches 6 or more, the transaction is generally considered safe and difficult to tamper with.

33. Double transaction

That is, I have 10 yuan, I use the 10 yuan to buy a pack of cigarettes, and then instantly use the 10 yuan that has not yet been paid. Bought another cup of coffee. So when verifying the transaction, you need to confirm whether the 10 yuan has been spent.

34. UTXO unspent transaction output

It is a data structure containing transaction data and execution code, which can be understood as digital currency that exists but has not yet been consumed.

35. Transactions per second TPS

That is throughput, tps refers to the number of transactions the system can process per second.

36. Wallet

Similar to Alipay, it is used to store digital currencies, and blockchain technology is more secure.

37. Cold wallet/hot wallet

A cold wallet is an offline wallet. The principle is to store it locally and use QR code communication to prevent the private key from touching the Internet. A hot wallet is an online wallet. The principle is to encrypt the private key and store it on the server. When it is needed, it is downloaded from the server and decrypted on the browser side.

38. Software Wallet/Hardware Wallet

A software wallet is a computer program. Generally speaking, a software wallet is a program that interacts with the blockchain and allows users to receive, store, and send digital currencies and can store multiple keys. Hardware wallets are smart devices that specialize in handling digital currencies.

39. Airdrop

The project sends digital currency to each user’s wallet address.

40. Mapping

Mapping is related to the issuance of blockchain currency and is a mapping between chains. For example, there are some blockchain companies that have not completed the development of the chain in the early stage. They rely on Ethereum to issue their own currency. The issuance and transactions of the early currency are all operated on Ethereum. With the development of the company, the company's own chain development has been completed. The company wants to map all the previous information on Ethereum to its own chain. This process is mapping.

41. Position

Refers to the ratio of the investor’s actual investment to the actual investment funds

42. Full position

Buy all the funds in Bitcoin

43. Reduce the position

Sell some of the Bitcoins, but not all of them

44. Heavy positions

Compared with Bitcoin, Bitcoin accounts for a larger share of funds

45. Short position

Compared with Bitcoin, the share of funds is larger

46. Short position

Sell all the Bitcoins you hold and convert them all into funds

47. Stop loss

After obtaining a certain profit, sell the Bitcoin held to keep the profit

48. Stop loss

After losses reach a certain level, sell the Bitcoins you hold to prevent further losses

49. Bull market

Prices continue to rise and the outlook is optimistic

50. Bear market

Prices continue to fall, and the outlook is bleak

51. Long (long)

The buyer believes that the currency price will rise in the future, buys the currency, and waits for the currency price After rising, sell at a high price to take profits

52. Short position (short selling)

The seller believes that the currency price will fall in the future, and sells the currency he holds (or borrows it from the trading platform) (coin) sell, wait for the price of the currency to fall, buy at a low price to take profits

53. Open a position

Buy virtual currencies such as Bitcoin

54 . Cover the position

Buy Bitcoin and other virtual currencies in batches, for example: buy 1 BTC first, and then buy 1 BTC later

55. Full position

All funds are purchased at one time to buy a certain virtual currency

56. Rebound

When the currency price falls, the price rebounds and adjusts because it falls too fast

57 .Consolidation (sideways)

The price fluctuation is small and the currency price is stable

58. Yin fall

The currency price declines slowly

59. Diving (waterfall)

The currency price fell rapidly and to a large extent

60. Cutting meat

After buying Bitcoin, the currency price fell, as Avoid expanding losses and selling Bitcoin at a loss. Or after borrowing the currency to go short, the price of the currency rises and you buy Bitcoin at a loss

61. Hold on

Expect the currency price to rise, but unexpectedly the currency price falls after buying; or expect the currency price to fall, but unexpectedly the currency price rises after selling

62. Unwinding

Buy Bitcoin The currency price fell after the currency caused a temporary book loss, but the currency price rebounded later, turning losses into profits

63. Going short

After selling Bitcoin because of the bearish market outlook, the currency price dropped All the way up, I failed to buy in time, so I failed to make profits

64. Overbought

The currency price continues to rise to a certain height, the buyer's power is basically exhausted, and the currency price is about to Fall

65. Oversold

The currency price continues to fall to a certain low, the seller's power is basically exhausted, and the currency price is about to rise

66. Lure buyers< /p>

The currency price has been consolidating for a long time and is more likely to fall. Most of the short sellers have sold Bitcoin. Suddenly the short sellers pulled up the currency price, inducing many parties to think that the currency price will rise and buy one after another. As a result, The short side suppresses the price of the currency, causing the long side to get stuck

67. Short-selling

After the bulls buy Bitcoin, they deliberately suppress the price of the currency, making the short sellers think that the currency price will fall, and sell them one after another. Out, and ended up falling into the trap of bulls

68. What is NFT

The full name of NFT is "Non-Fungible Tokens", which means non-fungible. Tokens, to put it simply, are an indivisible copyright certificate on the blockchain. They are mainly used to confirm and transfer the rights of digital assets. The difference from digital currencies is that they are unique and indivisible. In essence, they are a unique digital assets.

69. What is the Metaverse

The Metaverse is a collection of virtual time and space, consisting of a series of augmented reality (AR), virtual reality (VR) and the Internet (Internet) Composed of digital currency, which carries the function of value transfer in this world.

70. What is DeFi

DeFi, the full name is Decentralized Finance, which is "decentralized finance" or "distributed finance". "Decentralized finance", as opposed to traditional centralized finance, refers to various financial applications based on open decentralized networks. The goal is to establish a multi-level financial system based on blockchain technology and cryptocurrency. As a basis, re-create and improve the existing financial system

71. Who is Satoshi Nakamoto?

72. Bitcoin is different from Q Coin

Bitcoin is a decentralized digital asset with no issuing entity. Q Coin is owned by TencentThe electronic currency issued is similar to electronic points, but it is not actually currency. Q Coin requires a centralized issuing institution. Q Coin can only be recognized and used because of the credit endorsement of Tencent. The scope of use is also limited to Tencent's games and services. The value of Q coins is entirely based on people's trust in Tencent.

Bitcoin is not issued through a centralized institution, but it is widely recognized around the world because Bitcoin can self-certify its trust. The issuance and circulation of Bitcoin are jointly accounted for by miners across the entire network, and are not A central authority is also needed to ensure that no one can tamper with the ledger.

73. What is a mining machine?

Taking Bitcoin as an example, a Bitcoin mining machine is a professional equipment that competes for accounting rights by running a large amount of calculations to obtain new Bitcoin rewards. It is generally composed of a mining chip, a heat sink and a fan, and only performs A single calculation program consumes a lot of power. Mining is actually a competition between miners for computing power. Miners with more computing power have a greater probability of mining Bitcoin. As the computing power of the entire network increases, it becomes increasingly difficult to mine bits with traditional equipment (CPU, GPU), and people have developed chips specifically for mining. The chip is the core part of the mining machine. The operation of the chip will generate a large amount of heat. In order to dissipate heat, Bitcoin mining machines are generally equipped with heat sinks and fans. Users download Bitcoin mining software on their computers, use the software to assign tasks to each mining machine, and then start mining. Each currency has a different algorithm and requires different mining machines.

74. What is quantitative trading?

Quantitative trading, sometimes also called automated trading, refers to the use of advanced mathematical models to replace human subjective judgments, which greatly reduces the impact of investor sentiment fluctuations and avoids extreme fanaticism or pessimism in the market. make irrational investment decisions. There are many types of quantitative trading, including cross-platform trading, trend trading, hedging, etc. Cross-platform trading means that when the price difference between different target platforms reaches a certain amount, sell on the platform with a higher price and buy on the platform with a lower price.

75. Blockchain asset over-the-counter trading

Over-the-counter trading is also called OTC trading. Users need to find their own counterparties and do not need to match the transaction. The transaction price is determined by negotiation between the two parties. The two parties can fully communicate through face-to-face negotiation or telephone communication.

76. What is a timestamp?

The blockchain ensures that each block is connected sequentially through timestamps. Timestamps enable every piece of data on the blockchain to have a time stamp. Simply put, timestamps prove when something happened on the blockchain and cannot be tampered with by anyone.

77. What is a blockchain fork?

Upgrading software in a centralized system is very simple, just click "Upgrade" in the app store. But in decentralized systems such as blockchain, “upgrading”It’s not that simple, and a disagreement may even cause a blockchain fork. Simply put, a fork refers to a disagreement when the blockchain is "upgraded", resulting in a fork in the blockchain. Because there is no centralized organization, every code upgrade of digital assets such as Bitcoin needs to be unanimously recognized by the Bitcoin community. If the Bitcoin community cannot reach an agreement, the blockchain is likely to form a fork.

78. Soft fork and hard fork

Hard fork means that when the Bitcoin code changes, the old nodes refuse to accept the blocks created by the new nodes. Blocks that do not comply with the original rules will be ignored, and miners will follow the original rules and create new blocks after the last block they verified. A soft fork means that old nodes are not aware of the changes to the Bitcoin code and continue to accept blocks created by new nodes. Miners may work on blocks they have no understanding of, or validation of. Both soft forks and hard forks are "backwards compatible" to ensure that new nodes can verify the blockchain from scratch. Backward compatibility means that new software accepts data or code generated by old software. For example, Windows 10 can run Windows XP applications. Soft forks can also be "forward compatible".

79. Classification and application of blockchain projects

Judging from the current mainstream blockchain projects, blockchain projects mainly fall into four categories: Category 1: Currency; The second category: platform category; the third category: application category; the fourth category: asset tokenization.

80. USDT against the US dollar

USDT is Tether USD, a token launched by Tether that is against the US dollar (USD). 1USDT=1 US dollar, users can use USDT and USD for 1:1 exchange at any time. Tether implements a 1:1 reserve guarantee system, that is, each USDT token will have a reserve guarantee of 1 US dollar, which supports the stability of the USDT price. The unit price of a certain digital asset is USDT, which is equivalent to its unit price in US dollars (USD).

81. Altcoins and alternative coins

Altcoins refer to blockchain assets that use the Bitcoin code as a template and make some modifications to its underlying technology blockchain, among which Those with technological innovations or improvements are also called alternative coins. Because the Bitcoin code is open source, the cost of plagiarism in Bitcoin is very low. You can even generate a brand new blockchain by simply copying the Bitcoin code and modifying some parameters.

82. Three major exchanges

Binance: https://accounts.binancezh.ac/zh-CN

Okex: https://www .ouyi.top/

Huobi: https://www.huobi.af/zh-cn

83. Market software

Mytoken: http://www.mytoken.com/

Not small Number: https://www.feixiaohao.co/

84. Information website

Babbitt: https://www.8btc.cn

Golden Finance: http://www.jinse.com/

Coin World News: http://www.bishijie.com

85. Blockchain Browser

BTC: https://btc.com/

ETH: https://etherscan.io/

BCH: https://blockchair.com/bitcoin-cash /blocks

LTC: http://www.qukuai.com/search/ltc

ETC: https://gastracker.io/

86. Wallet

Imtoken: https://imatoken.net/

Bitpie: https://bitpie.com/

87. Decentralized Exchange

uniswap: https://uniswap.org

88. NFT Exchange

Opensea: https: //opensea.io

Super Rare: https://superrare.com/

89. Ladder

Bring your own, buy a reliable ladder

90. Platform currency

Digital currency issued by the platform, used to deduct handling fees, transactions, etc.

91. Bull market, bear market

Bull market : Rising market

Bear market: Falling market

92. Blockchain 1.0

A currency trading system based on distributed ledgers, represented by Bitcoin

93. Blockchain 2.0

The contract blockchain technology represented by Ethereum (smart contract) is 2.0

94. Blockchain 3.0

In the era of intelligent Internet of Things, it goes beyond the financial field to provide decentralized solutions for various industries

95. Smart Contract

Smart Contract is a A computer protocol designed to disseminate, verify or execute contracts in an information-based manner. Simply put, an electronic contract is set in advance and once confirmed by both parties, the contract is automatically executed.

96. What is a token?

The token economy is an economic system with Token as the only reference standard, which is equivalent to a pass. If you own Token, you have rights and interests, and you have the right to speak.

Big data is the means of production, AI is the new productivity, and blockchain is the new production relationship. Big data refers to a collection of data that cannot be captured, managed and processed within a certain time range using conventional software tools. It is a massive, high-growth and high-volume data set that requires new processing models to have stronger decision-making power, insight discovery and process optimization capabilities. Diverse information assets. Simply understood, big data is massive data accumulated over a long period of time and cannot be obtained in the short term. Blockchain can be used as a way to obtain big data, but it cannot replace big data. Big data is only used as a medium running in the blockchain and has no absolute technical performance, so the two cannot be confused. (A simple understanding of production relations is labor exchange and consumption relations. The core lies in productivity, and the core of productivity lies in production tools)

ICO, Initial Coin Offering, initial public token issuance, is the first step in the blockchain digital currency industry. Crowdfunding. It is the most popular topic and investment trend in 2017, and the country launched a regulatory plan on September 4. Speaking of ICO, people will think of IPO, and the two are essentially different.

99. Five characteristics of digital currency

The first characteristic: decentralization

The second characteristic: having open source code

The third feature: independent electronic wallet

The fourth feature: constant issuance

The fifth feature: global circulation

100. What is decentralization?

It has no issuer, does not belong to any institution or country, and is a publicly issued currency designed, developed and stored on the Internet by Internet network experts.

100. What is measurement (scarcity)?

Once the total issuance is set, permanently fixed, cannot be changed, cannot be over-issued at will, and can be subject to global Internet supervision. Because the difficulty of mining and mining changes over time, the longer the time, the greater the difficulty of mining, and the fewer coins are mined, so it is scarce.

101. What is open source code?

The alphanumeric code is stored on the Internet. Anyone can find out the source code of its design, everyone can participate, can mine it, and it is open to the world.

102. What is anonymous transaction? Private wallet private?

Everyone can register and download the wallet online without real-name authentication. It is completely composed of encrypted digital codes. It can be sent and traded globally in real-time point-to-point without resorting to banks or any institutions. It cannot be traced by anyone without my authorization. ,Inquire.

A contract transaction refers to an agreement between a buyer and seller to receive a certain amount of an asset at a specified price at a certain time in the future. The objects of contract trading are standardized contracts formulated by the exchange. The exchange stipulates standardized information such as commodity type, transaction time, quantity, etc. A contract represents the rights and obligations of the buyer and seller.

105. Digital Currency Industry Chain

Chip manufacturers, mining machine manufacturers, and mining machine agents mine and export to exchanges for retail investors to speculate in coins< /p>

106. Who is Erben?

Erben: Digital Currency Value Investor

Investment style: Steady

Building a community: Erben’s Miscellaneous Talks (High Quality Price Investment Community)

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107. Two investment strategies

Combining long and short term, focusing on price investment, no touching contracts, no short-term play

Reasonable layout, scientific operation, prudent and conservative, making periodic money

108. Two books?

Welcome currency friends and seek common development

8. Blockchain TPS

As we all know, Bitcoin can only conduct about 7 transactions per second, and Ethereum can only conduct about 7 transactions per second. The price is slightly better, only 10-20 transactions. As a payment system, this is far from enough. Some people often use this as an argument and think that the blockchain is inefficient.

In fact, there are many solutions trying to solve the TPS problem. For example, fabric can reach thousands of TPS, graphene series can reach tens of thousands of TPS, and the Off-chain of Bitcoin and Ethereum The plan theoretically supportsHold unlimited TPS. So does it mean that these new technologies are the future of blockchain? This question is always difficult to answer. There are a lot of things like consensus, distribution, and security.

I watched an interview with BM during the Chinese New Year. He mentioned a theory of VB that Scalability, Decentralization and Security cannot be taken into consideration in the blockchain, which is similar to the CAP theory in distributed systems.

I find this theory to be really simple, crude and effective in explaining blockchain technology.

For example: the alliance chain controls the number of verification nodes through the access mechanism, and improves Scalability by sacrificing decentralization; the same is true for the DPOS of the graphene series, and the consensus of RippleNet; Bitcoin improves the consensus of each node by increasing the number of verification nodes. The capacity of a block can also achieve the purpose of expansion, but the result is higher requirements for mining machines, forming a natural entry threshold, which actually sacrifices decentralization; both Bitcoin and Ethereum mining difficulty can be Adjustment and lowering the mining difficulty can actually improve Scalability, but the price paid is a decrease in attack resistance and security is sacrificed.

But this theory is invalid when it comes to off-chain solutions, such as the Lightning Network (Thunder Network), Ethereum’s plasma and R3 Corda (this one is quite special, it directly converts all chains into save). Children's shoes who are interested in the principles of the off-chain solution can go here, http://www.8btc.com/ln-rn-corda. The general plan is that both parties to the transaction lock reserves, package massive transactions and upload them to the chain, and only the final results of the transactions are saved on the chain. Through smart contracts and offline multi-signature mechanisms, cheating parties will be fined and forfeit reserves.

The Off-chain solution looks perfect, guaranteeing decentralization and security, while also allowing unlimited expansion.

But there is no free lunch in the world. Let’s take the Lightning Network as an example (in fact, I don’t fully understand plasma yet😅). At least it has the following shortcomings:

1. Bitcoin locked in the Lightning Network can only be used in the Lightning Network. Only when the transaction channel is closed can it truly become a currency recognized on the chain. This will theoretically lead to a situation similar to a bank run. If everyone loses confidence in the Lightning Network and closes channels centrally, it will bring down the Bitcoin network. However, this does not seem to be a big problem, as long as there are no loopholes in the Lightning Network, such as the signature algorithm being broken.

2. The transaction is inWith off-chain execution, the chain cannot verify whether the submitted transaction is the latest version. Although the script ensures that attackers who submit old versions of transactions risk being fined for reserve funds, the premise is that defenders monitor the network and submit evidence of updated versions of transactions. That is to say, the original passive defense of Bitcoin (the security of funds can be ensured without losing the private key) to active defense. From this perspective, it can be regarded as reducing security. It is unrealistic to leave this active defense operation to users. Eventually, some service companies will inevitably be spawned to save off-chain transaction certificates on behalf of users and prevent cheating. In a sense, it has changed from "disintermediation of trust" to the need to trust an intermediary. From this perspective, it seems that decentralization is also sacrificed.

3. In the Lightning Network, only the final fund status is saved, and all intermediate transaction details are ignored. Supporters believe that the user's privacy is protected, while opponents believe that transaction data is lost.

4. Because channels require reserves to be maintained, it is impossible for there to be a trading channel between any two users. Transfers between users can be done through transfers. In the end, it is likely that large funds will form a centralized Transit node.

9. How to understand blockchain in a simple and easy-to-understand manner

Blockchain is a technology that solves the core "trust" problem in the market economy. The cost of trust between strangers is reduced to an extremely low level.

There is one crucial thing in the market economy, which is "trust." Without trust, no transaction would be possible. If you go to the market to buy vegetables, if you don’t believe that the pesticide content in the vegetables meets the standard, you won’t do business with that dealer; if you go to a small store to buy a bottle of water, if the clerk doesn’t believe that what you give is genuine money, he won’t do it either. Sell ​​you the water.

The traditional small-scale farmer economy is an acquaintance economy. The scale of transactions is limited to people who are familiar with each other near the living area. Because an acquaintance cheats you, he will lose your social relationship and ruin his relationship with the entire acquaintance. Reputation in the circle. We believe that acquaintances are less likely to deceive us than strangers.

So, once we go beyond the scope of acquaintances, we need to use a very high cost to identify whether a stranger will cheat me, and how can I avoid the risk of being cheated. This situation will hinder transactions and restrict transactions.

In addition, trust issues naturally exist among people of different races, nationalities, cultures, religious beliefs, etc.

So in the market economy we are now in, why are there so many transactions between strangers? Because a new mechanism was born to solve the problem of trust among strangers.

So far, the most important mechanism to solve the trust problem is the "trust intermediary" institution and model.

As long as you and a stranger trust a third-party organization, you can use this third-party organization to solve the trust problem between you.

We call this third-party organization a trust intermediary.Governments and banks are trust intermediaries.

You think it’s okay to sell the goods you worked hard to produce to a stranger in exchange for a stack of RMB banknotes. That’s because the credit of the note-issuing bank and the authority of the government guarantee the guarantee. Currency value and validity of banknotes. Otherwise, who would want to sell something in exchange for a few pieces of ordinary paper?

In the age of the global village and the Internet, the people who buy your things may be strangers thousands of miles away who you have never met. The level of trust is even lower, so Alipay assumes the role of a trust intermediary. The buyer first pays the payment to Alipay's account. After receiving the goods and confirming that there is no problem, he agrees to transfer the payment to the seller. Taobao and other e-commerce companies have prospered rapidly in just over a decade.

The trust intermediary occupies a central position in the transaction system, and all transactions must use it to solve the trust problem.

However, the cost of trusting the intermediary itself is often huge.

As a trust intermediary, how much transaction tax does the government collect every year? Which industry is the most profitable? Financial services industry. Ant Financial, which owns Alipay, has annual profits exceeding 10 billion.

What does this mean? Both parties to the market actually paid a huge cost of trust.

If there is any way to eliminate or significantly reduce this trust cost, then the transaction costs of the general public can be reduced and the profits earned can be significantly increased.

So in the Internet era, blockchain technology came into play.

It allows transaction parties to get rid of intermediaries, solves the trust problem among strangers, and greatly reduces the cost of trust.

Because the blockchain can be expanded on a large scale, the data is open and transparent, and the data of each client is consistent, even if some clients are destroyed, the data security will not be affected. These highly reliable The technical characteristics can solve the problem of trust among strangers at low cost.

This technology can be extended to all areas that can be digitized, such as digital currency, payment settlement, digital bills, certificates of rights, credit reporting, government services, medical records, etc.

In the medium to long term, blockchain will be a revolutionary technology that will bring about huge social changes like the existing Internet, and will have huge investment value and money-making opportunities.

In the future, companies that can integrate blockchain into different scenarios to promote applications may be the next group of BATs, the next Google, Microsoft and Apple.

As the first practical application of blockchain technology, Bitcoin has been widely accepted and used around the world. Millions of users and tens of thousands of merchants have accepted Bitcoin, a digital currency. The payment, as the exchange value of currency, is growing, and even because the total amount is fixed, the long-term value is bullish, and it has become a safe-haven asset similar to gold, and the price has skyrocketed.