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❶ What is blockchain technology and how does it change business and financial models

What is blockchain technology and how does it change business and financial models? Joining the EU and NATO is just a cake-cake given by the West to satisfy hunger. In fact, at least in the current conflict between Russia and Ukraine, and before Russia and Ukraine fail to completely resolve the border issue, the dreams of the EU and NATO are just a dream for Ukraine! In Zhuang Ci's view, the positioning of basic subject research centers should be high enough and can be built on the basis of research institutes or universities with good foundations. The government should provide sufficient and stable support funds. An ideal operating model is to follow the example of Japan. "World's Top International Research Center (WPI)" program.

❷ What are the core blockchain technologies of blockchain technology?

What is the hottest Internet topic at the moment? You don’t need to explain it to me, it’s blockchain. Blockchain technology, but 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, which can be a public ledger (visible by anyone) or a permissioned network (visible only by those authorized), 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
Core technology 1. Block + chain:
Technically speaking, block is a data structure that records transactions. Reflects the flow of funds for 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 seconds), random number (recording the value of decrypting the answer to the math question related to the block), target hash value of the current block, and 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, input any string of data into SHA256 will get 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 the 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: realize the decentralization of accounting nodes
Core technology 5. P2P network:
P2P network (peer-to-peer network), also known as point-to-point technology, is no Central server, Internet system that 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 the blocks that meet the mining difficulty conditions in the Yuanfu network, and other nodes in the entire network verify that the blocks meet the mining difficulty conditions.After the mining difficulty conditions and the transaction data in the block meet the protocol specifications, each will link the block to its own version of the blockchain, thereby forming a consensus on the current network status in the entire network.
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. Each witness has two seconds of authority to generate blocks in order. If the witness cannot generate a block within the 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. Normally, 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.

❸ What is blockchain technology and how is it changing business and financial models

Blockchain technology is a distributed ledger technology that allows Multiple participants work together on a decentralized network to maintain a secure, transparent and immutable record. Blockchain technology was originally designed for the digital currency Bitcoin, but is now widely used in many other fields.

The core features of blockchain technology include:

Decentralization: Blockchain has no central control agency, and data is distributed on various nodes in the network, which makes it decentralized. The centralization feature reduces the risk of single points of failure.

Transparency: Transaction records on the blockchain are public to all participants, and anyone can view these records. This helps increase trust and reduce the risk of fraud.

Immutable: Once a transaction is recorded on the blockchain, it cannot be easily modified or deleted. This guarantees data integrity and security.

Smart contracts: Transactions on the blockchain can be automatically executed to implement "smart contracts", which automatically execute corresponding operations when specific conditions are met. This helps simplify complex business processes and reduce costs.

Blockchain technology has had a profound impact on business and financial models, which is mainly reflected in the following aspects:

Reducing costs: Blockchain technology can reduce intermediary links and reduce costs. Transaction costs and operating costs.For example, by adopting blockchain for cross-border payments, remittance fees can be significantly reduced.

Improving efficiency: The automation and smart contract features of blockchain technology help improve the efficiency of business processes, reduce manual intervention, and reduce error rates.

Enhance trust: The transparency and non-tamperability of blockchain technology help to establish a reliable trust system, reduce the risk of fraud, and provide better protection for commercial activities.

Innovative business models: Blockchain technology has spawned many new business models, such as decentralized finance (DeFi), digital asset trading, supply chain finance, etc. These new business models have brought disruptive changes to existing industries.

In short, blockchain technology, as an emerging technical means, is gradually changing the landscape of business and finance. With the continuous development of technology and the in-depth promotion of applications, blockchain is expected to have a more extensive and far-reaching impact in the future

❹ How to detect the risk level of blockchain smart contracts

With the acceleration of Shanghai's urban digital transformation, blockchain technology has been deeply applied in many fields such as government affairs, finance, logistics, and justice. During the application process, not only new business forms and business models have been born, but also many security issues have arisen, so security supervision is particularly important. As one of the important means of supervision, security evaluation has become a focus of many blockchain R&D manufacturers and application companies. This article talks about some of our exploration and practice on the blockchain compliance security assessment that everyone is concerned about.
1. Blockchain technology evaluation
Blockchain technology evaluation is generally divided into functional testing, performance testing and security evaluation.
1. Functional testing
Functional testing is a test of the basic functions supported by the underlying blockchain system, with the purpose of measuring the capabilities of the underlying blockchain system.
Blockchain functional testing is mainly based on GB/T 25000.10-2016 "System and Software Quality Requirements and Evaluation (SQuaRE) Part 10: System and Software Quality Model", GB/T 25000.51-2016 "System and Software Quality" Requirements and Evaluation (SQuaRE) Part 51: Quality Requirements and Testing Details for Ready to Use Software Products (RUSP)" and other standards to verify whether the software under test meets the requirements of relevant test standards.
Blockchain function testing specifically includes networking methods and communication, data storage and transmission, encryption module availability, consensus function and fault tolerance, smart contract function, system management stability, chain stability, privacy protection, and interoperability , account and transaction types, private key management solutions, audit management and other modules.
2. Performance testing
Performance testing is a type of test implemented and executed to describe the performance-related characteristics of the test object and evaluate it. Most of them are used in project acceptance evaluation to verify the established Whether the technical indicators are completed.
Blockchain performance testing specifically includes high concurrency stress testing scenarios and peak impact testing.Modules such as test scenarios, long-term stable operation test scenarios, query test scenarios, etc.
3. Security Assessment
Blockchain security assessment mainly conducts security testing and evaluation of account data, cryptography mechanisms, consensus mechanisms, smart contracts, etc.
The main basis for blockchain security evaluation is "DB31/T 1331-2021 General Requirements for Blockchain Technology Security". You can also refer to standards such as "JR/T 0193-2020 Blockchain Technology Financial Application Assessment Rules" and "JR/T 0184-2020 Financial Distributed Ledger Technology Security Specifications" based on actual testing needs.
Blockchain security assessment specifically includes storage, network, computing, consensus mechanism, cryptography mechanism, timing mechanism, personal information protection, networking mechanism, smart contracts, services and access, etc.
2. Blockchain Compliance Security Assessment
Blockchain compliance security assessment generally includes “Blockchain Information Service Security Assessment”, “Network Security Level Protection Assessment” and “Special Funding Projects” "Acceptance Evaluation" three categories.
1. Blockchain information service security assessment
Blockchain information service security assessment is mainly based on the "Blockchain Information Service Management Regulations" issued by the Cyberspace Administration of China on January 10, 2019 (hereinafter referred to as "Regulations") and refer to the national blockchain standard "Blockchain Information Service Security Specification (Draft for Comments)".
The "Regulations" aim to clarify the information security management responsibilities of blockchain information service providers, standardize and promote the healthy development of blockchain technology and related services, avoid blockchain information service security risks, and provide blockchain Provide effective legal basis for the provision, use and management of information services. Article 9 of the "Regulations" states: Blockchain information service providers that develop and launch new products, new applications, and new functions must report to the national and provincial, autonomous region, and municipality Internet Information Offices for security assessment in accordance with relevant regulations.
The "Blockchain Information Service Security Specification" is a construction and preparation project led by the Institute of Information Engineering of the Chinese Academy of Sciences and jointly participated by Zhejiang University, China Electronics Technology Standardization Institute, Shanghai Information Security Evaluation and Certification Center and other units. National standards for evaluating the security capabilities of blockchain information services. The "Blockchain Information Service Security Specification" stipulates the security requirements that blockchain information service providers of alliance chains and private chains should meet, including security technical requirements and security assurance requirements as well as corresponding test and evaluation methods, and is suitable for guiding blockchain Chain information service security assessment and blockchain information service security construction. The security technical requirements and guarantee requirements framework proposed by the standard are as follows:
Figure 1 Blockchain information service security requirements model
2. Network security level protection evaluation
The main basis for network security level protection evaluation includes "GB/T 22239-2019 Basic Requirements for Network Security Level Protection" and "GB/T 28448-2019 Network Security Level Protection Evaluation Requirements".
As an emerging information technology, the application system built by blockchain is also an object of level protection and needs to be evaluated for level protection in accordance with regulations. The general requirements for level protection security evaluation are applicable to the evaluation of the infrastructure part of the blockchain, but currently there are no specific security requirements for the blockchain. Therefore, the expansion requirements for blockchain security evaluation still need to be further explored and studied.
3. Special fund project acceptance evaluation
According to the relevant regulations of the Municipal Economic and Information Technology Commission, information technology special fund projects are required to issue a safety evaluation report during project acceptance. The acceptance evaluation of blockchain application projects will be carried out in accordance with Shanghai’s latest blockchain local standard "DB31/T 1331-2021 General Requirements for Blockchain Technology Security".
3. Exploration and practice of blockchain security assessment
1. Standard preparation
Shanghai Assessment Center actively participates in the preparation of blockchain standards. Led by the Shanghai Evaluation Center, Suzhou Tongji Blockchain Research Institute Co., Ltd., Shanghai Qiyin Information Technology Co., Ltd., Shanghai Moheng Network Technology Co., Ltd., the First Research Institute of Telecommunications Science and Technology and other units participated in the preparation of the blockchain local standard " DB31/T 1331-2021 "General Requirements for Blockchain Technology Security" was officially released in December 2021 and will be officially implemented on March 1 this year. The blockchain national standard "Blockchain Information Service Security Specification", which the Shanghai Assessment Center participated in the preparation of, is in the stage of soliciting opinions.
At the same time, the assessment center also participated in the compilation of primary and intermediate textbooks for blockchain engineering technicians organized by the Ministry of Human Resources and Social Security and led by Tongji University, and was responsible for compiling the chapter "Testing the Blockchain System".
2. Project Practice
In recent years, the Shanghai Assessment Center has conducted a large number of blockchain security assessment practices based on relevant technical standards, including grade protection assessment, information service security assessment, project security assessment, etc. In the evaluation practice, the main security issues discovered are as follows:
Table 1 Blockchain is mainly a security issue
Serial number
Evaluation items
Problem description
1
Consensus Algorithm
The consensus algorithm uses Kafka or Raft consensus and does not support Byzantine fault tolerance or tolerate malicious node behavior.
2
On-chain data
On-chain sensitive information is not encrypted, and all data on the chain can be accessed through the query interface or blockchain browser.
3
Cryptographic Algorithm
The random numbers used in the cryptographic algorithm do not meet the randomness requirements of GB/T 32915-2016.
4
Node Protection
For the alliance chain, security protection measures failed to be configured for the area where the node server is located.
5
Communication transmission
When communicating between nodes, the blockchain and upper-layer applications, no secure information transmission channel has been established.
6
Consensus calculationMethod
The number of nodes deployed in the system is small, and sometimes the number of fault-tolerant nodes required by the consensus algorithm is not even reached.
7
Smart Contract
The operation of the smart contract is not monitored, and problems that arise during the operation of the smart contract cannot be discovered and dealt with in a timely manner.
8
Services and Access
Upper-layer applications have access control flaws such as unauthorized and unauthorized access, leading to business confusion and data leakage.
9
Smart Contract
Smart contract coding is not standardized. When an error occurs in the smart contract, the smart contract freezing function is not provided.
10
Smart Contract
The running environment of smart contracts is not isolated from the outside, and there is a risk of external attacks.
3. Tool Application
When the evaluation center organized and compiled the "DB31/T 1331-2021 General Requirements for Blockchain Technology Security", it has considered the connection needs with the graded protection evaluation. The "infrastructure layer" security in DB31/T 1331 is consistent with the relevant requirements of the secure physical environment, secure communication network, security area boundary, secure computing environment, security management center, etc. of level protection, "protocol layer security", "extension layer" "Security" more reflects the unique security protection requirements of the blockchain.
Based on the relevant security requirements of DB31/T 1331, the assessment center is organizing and compiling extended blockchain assessment requirements. The relevant results will be applied to the network security level protection assessment tool - Assessment Expert. By then, evaluation institutions using the "Evaluation Expert" software will be able to carry out blockchain security evaluations accurately, standardly and efficiently, discover blockchain security risks, and put forward corresponding rectification suggestions

❺ Blockchain Financial application innovation platform, chain application, how to operate bonds

Blockchain financial application Blockchain bond operation preparation Blockchain + bond blockchain has the potential to replace the traditional issuance of securities because of its unique advantages Methods and trading models, establish a new blockchain securities market network, complete certification, confirmation of rights, issuance, trading, traceability and other tasks, and also help eliminate fraud, breach of contract
and other behaviors, and achieve real-time penetrating supervision. The biggest difference between traditional bonds and blockchain bonds is that the traditional model is based on centralized peer-to-peer bonds. The center may be an intermediary or electronic account, while blockchain bonds are decentralized or decentralized. Intermediary peer-to-peer circulation of bonds can help improve efficiency and solve problems such as information asymmetry. Blockchain + IPO makes IPO-related information transparent and public through the blockchain, allowing investors to follow traces and increasing their fraud costs. Building a consortium chain By forming a consortium chain and deploying bond issuance on the blockchain to achieve point-to-point issuance, the role of securities underwriting institutions can be weakened and underwriting fees can be reduced. Smart bonds (create smart contracts) When a certain transaction condition is met, both parties to the bond transaction complete the transaction according to the pre-agreed securities transaction price and transaction quantity. SuchThe contract is turned into code and written into the blockchain. Once the conditions are triggered, the blockchain system will automatically start the payment code of the smart contract, and the securities and other valuable assets involved will be automatically traded according to the contract and liquidated in real time. Delivery. It effectively simplifies the issuer's default behavior. Smart securities avoid the manual process of traditional financial transactions and save time and costs. Its design allows both parties to the securities transaction to no longer rely on third-party credit intermediaries. It also helps to speed up transactions while reducing costs. Human error and operational risk.