区块链技术的指标有哪些,区块链技术的指标包括

1. What is blockchain technology? What are the core components of blockchain technology?

From a technical perspective and an architectural perspective, I will tell you in popular language. Let me talk about some of my understanding of blockchain.

What exactly is blockchain? Block chain, in a word, blockchain is a storage system, and the storage system is more detailed. Block chain is a distributed storage system without an administrator, and each node owns all data.

What do common storage systems look like?

First, let’s take a look at how to ensure high availability?

Ordinary storage systems usually use "redundancy" to solve high availability problems. As shown in the figure above, if the data can be copied into several copies and redundantly spread to multiple places, high availability can be ensured. If the data in one place is down, there will still be data in another place. For example, the master-slave cluster of MySQL has this principle, and the RAID of the disk also has this principle.

Two points that need to be emphasized here are: data redundancy, which often causes consistency problems

1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing. Sometimes, it actually means that there is inconsistency between reading and writing for a short period of time. This is a side effect of data redundancy.

2. The second point is that data redundancy often reduces writing efficiency, because data synchronization also consumes resources. If you look at single-point writing, if two slave libraries are added, the writing efficiency will actually be affected. Ordinary storage systems use redundancy to ensure high data availability.

Then the second question is, can an ordinary storage system perform multiple writes?

The answer is yes, for example, take this picture as an example:

In fact, MySQL can do a dual-master master-slave synchronization, dual-master master-slave synchronization, two nodes , and can be written at the same time. If you want to build a multi-machine room and multi-active data center, in fact, multi-machine room and multi-active data center also requires data synchronization. What should be emphasized here is that multi-point writing often leads to consistency issues of write-write conflicts. Taking MySQl as an example, assuming that the attribute of a table is an auto-increment ID, then the data in the database is now 1234, then one of the nodes When writing, a piece of data is inserted, it may become 5. Then these 5 pieces of data are synchronized to another master node. Before the synchronization is completed, if another writing node also inserts a piece of data, it will also generate A piece of data with an auto-incrementing ID of 5 is obtained. Then, after it is generated, it is synchronized to another node, and then when the synchronized data arrives, it will conflict with the two local 5s, and the synchronization will fail, which will cause write consistency conflicts. This problem will occur if there are multiple writes.

How to ensure consistency when writing multiple points?

Weixin’s “Swan Master Class” will give you more technical work

2. What are the basic characteristics of blockchain

Features:

Decentralization. Blockchain technology does not rely on additional third-party management agencies or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes self-verification, transmission and management of information through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain.

Openness. The foundation of blockchain technology is open source. In addition to the private information of the transaction parties being encrypted, the data of the blockchain is open to everyone. Anyone can query the blockchain data and develop related applications through the public interface. Therefore, the entire System information is highly transparent.

Independence. Based on consensus specifications and protocols (similar to various mathematical algorithms such as the hash algorithm used by Bitcoin), the entire blockchain system does not rely on other third parties. All nodes can automatically and securely verify and exchange data within the system without the need for any human intervention.

Security. As long as you cannot control 51% of all data nodes, you cannot manipulate and modify network data at will. This makes the blockchain itself relatively safe and avoids subjective and artificial data changes.

Anonymity. Unless required by legal regulations, technically speaking, the identity information of each block node does not need to be disclosed or verified, and information transfer can be carried out anonymously.

(2) Extended reading of indicators of blockchain technology:

Examples

The largest application of blockchain technology at present is The invention of digital currencies such as Bitcoin. Because the essence of payment is to "add the reduced amount in account A to account B."

If people have a public account book that records all transactions of all accounts so far, then for any account, people can calculate the amount of money it currently holds. The blockchain is precisely the public account book used to achieve this purpose, which saves all transaction records. In the Bitcoin system, the Bitcoin address is equivalent to the account, and the number of Bitcoins is equivalent to the amount.

3. What are some important elements of blockchain technology?

1. The so-called blockchain technology, referred to as BT (Blockchain technology), is also called distributed ledger technology , is an Internet database technology that is characterized by decentralization, openness and transparency, allowing everyone to participate in database records.
2. Blockchain is an innovative application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm in the Internet era. In recent years, the development and application of blockchain have had a profound impact on technology. Innovation and industrial revolution are of great significance. This experience introduces relevant knowledge of blockchain technology.
3. Blockchain is a distributed ledger that can contain financial and/or non-financial transactions, replicated (distributed) across multiple systems in near real-time through a peer-to-peer network, and each participant "owns" the same A copy of the ledger and get updates when any transactions are added, each participant contributesUsed to establish the inherent "immutability" of all existing records, use cryptography and digital signatures to prove identity, authenticity and enforce read/write access, have mechanisms in place to make it difficult to alter historical records, and can easily detect attempts to Change it.

4. What are the characteristics of blockchain?

There are five main technical characteristics of blockchain, namely: decentralization, information cannot be tampered with, openness and transparency, and collective maintenance. sex, reliable database. It can be used in many aspects, for example, let’s take a rental agency. In the past, the agency had information about the property and the tenants. Moreover, some unscrupulous agents would change the information at will, just to make money in the middle. More agency fees. And if a blockchain is built and applied in the rental field, then the property information will be filled in by the landlord, and the tenant's information will be filled in by the tenant. Note that once the information is filled in, it cannot be changed twice. So this is equivalent to removing the center of intermediary. Of course, we are just talking briefly. In fact, deploying such a blockchain is also very complicated.

5. What are the several elements in blockchain technology

The elements of Jinwowo network analysis are as follows:

1-Contains a distribution Database

2-Distributed database is the physical carrier of the blockchain, and the blockchain is the logical carrier of transactions. All core nodes should contain a full copy of the blockchain data

3-The blockchain serializes blocks by time, and the blockchain is the only subject of transaction data in the entire network

4-The blockchain is only valid for additions, not for other operations Invalid

5-Public and private key verification based on asymmetric encryption

6-Accounting nodes require that the Byzantine Generals Problem can be solved/avoided

7- The consensus process (consensus progress) is evolutionarily stable, that is, it will not collapse in the face of a certain amount of contradictory data from different nodes.

8-The consensus process can solve the double-spending problem

6. What are the core blockchain technologies of blockchain technology?

Now What is the hottest topic on the Internet? You don’t need to tell me that it is blockchain technology. However, many friends have only heard of this technology and do not have much in-depth understanding of it. So what are the blockchain technologies? ? Below we will bring you an introduction to the core technology of blockchain for your reference.
What are the core elements of blockchain technology?
Blockchain technology can be a public ledger (visible by anyone) or a permissioned network (visible only by those authorized), which solves supply chain challenges , because it is an immutable record that is shared among network participants and updated in real time.
Blockchain Technology----Data Layer: Designing the Data Structure of the Ledger
CoreTechnology 1. Block + Chain:
Technically speaking, block is a data structure that records transactions, reflecting the flow of funds in a transaction. The blocks of transactions that have been reached in the system are connected together to form a main chain, and all nodes participating in the calculation record the main chain or part of the main chain.
Each block consists of a block header and a block body. The block body is only responsible for recording all transaction information in the previous period, mainly including the number of transactions and transaction details; the block header encapsulates the current version number, previous A block address, timestamp (recording the time when the block was generated, accurate to the second), random number (recording the value of decrypting the answer to the math question related to the block), the target hash value of the current block, and the Merkle number Root value and other information. From a structural point of view, most functions of the blockchain are implemented by the block header.
Core technology 2. Hash function:
The hash function can convert data of any length into a set of fixed-length codes through the Hash algorithm. The principle is based on a cryptographic one-way hash function. This kind of function is easy to verify, but difficult to crack. Usually, the industry uses y=hash(x) to represent it. This hash function implements operations on x to calculate a hash value y.
Commonly used hash algorithms include MD5, SHA-1, SHA-256, SHA-384 and SHA-512, etc. Taking the SHA256 algorithm as an example, inputting any string of data into SHA256 will result in a 256-bit Hash value (hash value). Its characteristics: the same data input will get the same result. As long as the input data changes slightly (for example, a 1 becomes a 0), a completely different result will be obtained, and the result cannot be predicted in advance. Forward calculation (calculating the corresponding Hash value from the data) is very easy. Reverse calculation (cracking) is extremely difficult and is considered impossible under current technological conditions.
Core technology 3. Merkle tree:
Merkle tree is a hash binary tree, which can be used to quickly verify the integrity of large-scale data. In the blockchain network, the Merkle tree is used to summarize all transaction information in a block, and ultimately generates a unified hash value of all transaction information in the block. Any change in transaction information in the block will cause Merkle tree changes.
Core technology 4. Asymmetric encryption algorithm:
Asymmetric encryption algorithm is a key secret method that requires two keys: public key and private key. The public key and the private key are a pair. If the public key is used to encrypt data, only the corresponding private key can be used to decrypt it, thereby obtaining the corresponding data value; if the private key is used to sign the data, then only the corresponding public key can be used to sign the data. In order to verify the signature, the sender of the verification information is the holder of the private key.
Because encryption and decryption use two different keys, this algorithm is called an asymmetric encryption algorithm, while symmetric encryption uses the same key in the encryption and decryption processes.
Blockchain technology----network layer: realizing the decentralization of accounting nodes
Core technology 5. P2P network:
P2P network (peer-to-peer network), also known as point-to-point technology, is an Internet system that does not have a central server and relies on user groups to exchange information. Unlike a centralized network system with a central server, each client in a peer-to-peer network acts as both a node and a server. Domestic Xunlei software uses P2P technology. The P2P network has the characteristics of decentralization and robustness.
Blockchain technology----Consensus layer: allocate the task load of accounting nodes
Core technology 6. Consensus mechanism:
Consensus mechanism is how to reach consensus among all accounting nodes to identify The validity of a record is both a means of identification and a means of preventing tampering. There are currently four main types of consensus mechanisms: PoW, PoS, DPoS and distributed consensus algorithms.
PoW (Proof of Work, proof of work): PoW mechanism, which is like Bitcoin’s mining mechanism, miners package existing transactions that have not been recorded by the network into a block, and then continue to traverse and try to find a random number , so that the hash value of the new block plus the random number meets certain difficulty conditions. Finding a random number that meets the conditions is equivalent to determining the latest block of the blockchain, and is also equivalent to obtaining the current round of accounting rights of the blockchain. Miners broadcast blocks that meet the mining difficulty conditions in the Yuanfu network. After verifying that the block meets the mining difficulty conditions and that the transaction data in the block meets the protocol specifications, other nodes in the entire network will each Blocks are linked to their own version of the blockchain, thereby forming a network-wide consensus on the current network state.
PoS (ProofofStake, Proof of Stake): PoS mechanism requires nodes to provide proof of a certain number of tokens to obtain a distributed consensus mechanism for competing for blockchain accounting rights. If you rely solely on the token balance to determine the bookkeeper, you will inevitably make the rich win, which will lead to the centralization of bookkeeping rights and reduce the fairness of the consensus. Therefore, different PoS mechanisms use different methods to increase the amount of money based on the proof of equity. The randomness of accounting rights avoids centralization. For example, in the PeerCoin PoS mechanism, the Bitcoin with the longest chain age has a greater chance of obtaining accounting rights. NXT and Blackcoin use a formula to predict the next accounting node. The more tokens you own, the greater the probability of being selected as an accounting node. In the future, Ethereum will also switch from the current PoW mechanism to a PoS mechanism. Judging from the information currently available, Ethereum's PoS mechanism will use nodes to place bets on the next block. The winner of the bet will receive an additional Ethereum currency award. Those who do not win will be deducted Ether coins to reach consensus on the next block.
DPoS (DelegatedProof-Of-Stake, share authorization certificate): DPoS is easy to understand and is similar to the modern corporate board of directors system. The DPoS mechanism adopted by BitShares is that shareholders vote to select a certain number of witnesses, and each witness has two seconds of authority in sequence.Time generates blocks. If a witness cannot generate a block in a given time slice, the block generation authority is given to the witness corresponding to the next time slice. Shareholders can replace these witnesses at any time by voting. This design of DPoS makes the generation of blocks faster and more energy-saving.
Distributed Consistency Algorithm: Distributed Consistency Algorithm is based on traditional distributed consistency technology. Among them are Byzantine fault-tolerant algorithms that solve the Byzantine Generals problem, such as PBFT (Byzantine fault-tolerant algorithm). In addition, distributed consensus algorithms (Pasox, Raft) that solve non-Byzantine problems are not explained in this article. This type of algorithm is currently a commonly used consensus mechanism in alliance chain and private chain scenarios.
Taken together, POW is suitable for public chains. If you build a private chain, it is more suitable to use POS because there is no trust problem in verification nodes; and because there are untrustworthy local nodes in the alliance chain, it is more suitable to use DPOS.
Blockchain technology----Incentive layer: Develop a "salary system" for accounting nodes
Core technology 7. Issuance mechanism and incentive mechanism:
Take Bitcoin as an example. Bitcoins are initially rewarded by the system to miners who create new blocks, and this reward is halved approximately every four years. At the beginning, miners were rewarded with 50 Bitcoins for each new block recorded, and this reward is halved approximately every four years. By analogy, by around AD 2140, newly created blocks will no longer receive rewards from the system. By then, the total number of Bitcoins will be approximately 21 million. This is the total number of Bitcoins, so it will not increase indefinitely.
Another source of incentives is transaction fees. When there are no system rewards for newly created blocks, the miners' income will change from system rewards to transaction fees. For example, when you transfer, you can specify 1% of it as a handling fee to be paid to the miner who records the block. If the output value of a transaction is less than the input value, the difference is the transaction fee, which will be added to the incentive for that block. As long as a given amount of electronic currency has entered circulation, the incentive mechanism can gradually be converted to rely entirely on transaction fees, so there is no need to issue new currency.
Blockchain technology----Contract layer: giving the ledger programmable features
Core technology 8. Smart contract:
Smart contract is a set of programmed rules and logic that respond to scenarios. Implemented by decentralized, trusted shared script code deployed on the blockchain. Usually, after the smart contract is signed by all parties, it is attached to the blockchain data in the form of program code, and is recorded in a specific block of the blockchain after being propagated through the P2P network and verified by nodes. Smart contracts encapsulate a number of predefined states and transition rules, scenarios that trigger contract execution, response actions under specific scenarios, etc. The blockchain can monitor the status of smart contracts in real time, and activate and execute the contract by checking external data sources and confirming that specific trigger conditions are met.
The above is what blockchain technologies the editor has brought to you? All content of the introduction to the core technology of blockchain.

7. Blockchain audit objectivesClassification

Under blockchain technology, the traditional audit objectives of authenticity and integrity are no longer important, and need to shift to risk warning and decision support.
First of all, the irreversibility and timestamp of the blockchain can ensure that the data is not modified at will. In the blockchain system, the premise for each transaction to be valid is that the system reaches a consensus on the ownership of digital assets, and once reached, it cannot be modified. Reflected in the audit, after a transaction occurs and is recorded, if you try to modify it, subsequent accounting processing requires all blockchains to be modified, and it will be very difficult to falsify it.
Secondly, under the distributed accounting rules, transaction data is stored in each block, and each block is shared by traders and confirmers. If a block fails or is attacked, the chain will Other participants can still operate as usual and keep copies of the books recording complete data, which ensures the integrity of the accounting data.
In the audit work, as long as the transactions are verified for fraud, the authenticity and completeness audit objectives can be quickly achieved. For example, in traditional raw material audits, it is necessary to verify the invoices, inspections and warehousing of the procurement process. Now it is only necessary to verify the authenticity of the invoices and physical objects in the warehousing process, and other links can be omitted. For example, when department A picks materials, other departments will also record the quantity of materials picked by department A. If department A wants to modify its own quantity of materials, it needs to modify the records of all other departments at the same time, which is very difficult. This guarantees Authenticity and completeness of material collection records. Correspondence and verification of accounts receivable, accounts payable, and transactions can also be handled similarly.
In short, due to the non-modifiable and public nature of the blockchain, the correctness and legality of transaction rights and obligations, pricing, deadlines, posting and summary, classification, and disclosure can be effectively guaranteed. The focus of auditing should shift to in-process supervision, risk warning and decision-making support. For example, if certain monitoring and analysis indicators are set in the blockchain audit software, abnormal operating behavior of the audited unit can be discovered at any time to achieve ongoing supervision. Set thresholds for key indicators, such as automatic early warning when the bad debt rate of accounts receivable reaches 20%, reminding auditors of problems, changing regular audits to "all-weather" audits, and giving full play to the risk warning function. In addition, blockchain technology has an auxiliary decision-making function due to its large amount of data and data processing capabilities. During the audit process, blockchain data analysis capabilities can be used to trace the recovery of accounts receivable and bad debts, and propose relevant solutions. Targeted improvement suggestions.

8. What are the main characteristics of blockchain technology

It is understood that compared with traditional centralized solutions, blockchain technology mainly has the following three characteristics:

The core idea of ​​blockchain is decentralization

In the blockchain system, the rights and obligations between any nodes are equal, and all nodes have the ability to Use computing power to vote, thereby ensuring that the recognized result is the result recognized by more than half of the nodes. Even if you suffer a serious hacker attack, as long as the number of nodes controlled by the hacker does not exceed half of the total number of global nodes,The system will still be able to run normally and the data will not be tampered with.

The biggest subversion of blockchain is the establishment of credit

Theoretically, blockchain technology can make WeChat Pay and Alipay no longer valuable. "The Economist" gave a vivid metaphor to the blockchain: simply put, it is "a machine that creates trust." Blockchain allows people to collaborate without trusting each other and without a neutral central authority. Combating counterfeit currency and financial fraud will no longer be needed in the future.

The collective maintenance of blockchain can reduce costs

In a centralized network system, the maintenance and operation of the system rely on the operation, maintenance and operation of platforms such as data centers, and costs Cannot be omitted. Anyone can participate in the nodes of the blockchain. While participating in the recording, each node also verifies the correctness of the recording results of other nodes, which improves maintenance efficiency and reduces costs.

In one sentence, blockchain touches money, trust and power, which are the fundamental foundations on which human beings rely for survival.