Analysis of blockchain digital currency
If you want to understand the application of blockchain, you can refer to many books and opinions, such as illustrated blockchain, blockchain: reshaping the economy and the world, blueprint and guide of new economy, and articles of coin'an community, including a detailed understanding of the platform of coin'an community, with great strength
As the name suggests, blockchain is composed of block and chain. It is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and so on. It is a kind of chain data structure that combines data blocks in order according to the time sequence, and it is a secure and reliable distributed account book that can not be tampered with and forged by means of cryptographyin 2008, in his paper bitcoin: a peer-to-peer e-cash system published by Nakamoto, he first proposed the idea of blockchain and encrypted digital currency. Starting from bitcoin, blockchain has become the underlying technology of various digital currencies
Second, the working principle of blockchain:1. The basic concepts include: (1) transaction: one operation will change the account status once, such as adding a record 2) Block: records the transaction and status data within a specified time, which is a consensus and preservation of the current account status 3) Chain: it is composed of a series of blocks in chronological order, which is the log record of the whole state change. If you understand the working concept of blockchain, it is not difficult to understand its working principle. Suppose there is a distributed data logbook, which can only be added, not deleted or changed. Its structure is a linear chain formed by a series of "blocks" (which is also the source of the name of "blockchain"), and new data must be put into a new block to be added, The maintenance node can propose a new block, but it must go through a certain consensus mechanism to reach an agreement on the final selected block
2. Take bitcoin as an example to see the working principle of blockchain
the block of bitcoin is divided into block head and block body
Core advantages and characteristics of blockchain1. The verification, accounting, storage, maintenance and transmission of decentralized blockchain data are all based on distributed system structure. There is no centralized hardware or management organization, and the rights and obligations of any node are equal, The data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system. 2. The open and transparent system is open. In addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all. Anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent. 3. Security blockchain uses consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work. 4. Information cannot be tampered with. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% (almost impossible) nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid. Therefore, the data stability and reliability of the blockchain are extremely high. 5. Anonymity because the exchange between nodes follows a fixed algorithm, and its data interaction does not need trust (the program rules in the blockchain will judge whether the activity is effective or not). Therefore, the counterparties do not need to let the counterparties generate their own trust by disclosing their identities, which is very helpful for credit accumulation
At present, the most popular classification of blockchain is to divide blockchain into public blockchain, private blockchain and consortium blockchain according to different participants1. Public chain: anyone can participate in the use and maintenance, and can obtain the effective confirmation of the blockchain. Public chain is the earliest blockchain and the most widely used blockchain at present, such as bitcoin blockchain. The information is completely public
if the licensing mechanism is introced, it includes private chain and alliance chain. 2. Private chain: a company or indivial only uses the blockchain technology, enjoys the exclusive write permission of the blockchain, and does not disclose the information. At present, conservative giants (traditional finance) want to experiment with private blockchain, and the application procts of private blockchain are still groping. 3. Alliance chain: it is a blockchain between the public chain and the existing chain, which is jointly controlled by multiple organizations. The use of the chain is managed with authority, which can be controlled by the manager, and also open to others according to the manager's wishes. In addition, according to the different use scenarios and purposes of blockchain, it can be divided into currency chain for the purpose of digital currency, property chain for the purpose of recording property rights, and crowdfunding chain for the purpose of crowdfunding
On May 28, Ma Huateng, CEO of Tencent, proposed the anti-counterfeiting method based on cloud integrated blockchain technology, which is far more efficient than traditional anti-counterfeiting methods. The future anti-counterfeiting verification scenario may only require users to use their mobile phones for simple scanning, and a large number of complete information based on different dimensions can be obtainedtake Maotai liquor as an example:
distillery address, proction workshop, operation staff, inspector, delivery time, transportation vehicle information and driver information,
liquor year, raw material source, raw material supplier, storage warehouse number, raw material transportation vehicle and driver information,
all information can be accurately traced, permanently recorded and tampered with
the above information can be easily verified
2. Food safety issues as early as last November, Wal Mart has cooperated with IBM to track the source of food by using blockchain technology, so as to ensure the safety of food and increase the circulation of food to rece costs. For Wal Mart and other large supermarkets, it took a few days to investigate the source of problem food, After using this technology, only one item of proct information is needed to achieve accurate traceability, and important information such as food origin, inspector, supplier, logistics and transportation can quickly find problems in a few minutes. Currently, procts tracked by blockchain include packaging procts from the United States and pork from China
3. Information security
blockchain technology is promoting an information security technology revolution. (1) identity protection PKI is a common public key encryption technology in e-mail, message application, website and other communication applications. However, since the implementation of most PKI, the centralized trusted third party certification authority (CA) is used to issue, activate and store user certificates. Hackers can attack PKI to fake user identity or crack encrypted information
certcoin is the first PKI implementation of blockchain, which comes from MIT, removes the centralized authentication center, and uses blockchain as a distributed ledger for domain name and public key
pomcor company: blockchain PKI implementation path: keep the authentication center, and use blockchain to store the hash value of issued and activated certificates. Users can verify the authenticity of certificates through decentralized and transparent sources, and can also improve the network access performance through local authentication of secret key and signature based on blockchain
(2) data integrity protection
guardtime developed a secret key free signature architecture (Ksi) based on blockchain technology to replace the secret key based data authentication technology. Ksi stores the hash table of the original data and files on the blockchain, runs the hash algorithm to verify other copies, and compares the results with the data stored in the blockchain. Any data tampering will be found quickly because the original hash table is stored in millions of nodes
(3) key infrastructure protection
the "Achilles heel" of the Internet, DDoS has entered the TB era, DDoS is still the simplest weapon for hackers to bring down the big target with low cost, DNS service is the primary target for hackers to carry out large-scale destruction, but blockchain technology is expected to fundamentally solve the problem
The distributed storage ofblockchain makes hacker attacks lose focus. Nebulis is developing a distributed DNS system, which uses Ethereum blockchain and interstellar Internet file system (IPFs, the distributed substitute of HTTP) to register and resolve domain names. The biggest weakness of DNS is caching, which makes DDoS attacks possible. It is also the bane of the centralized government's censorship of social networks and manipulation of DNS registration. A highly transparent and distributed DNS system can effectively prevent any entity, including the government, from arbitrarily manipulating records
(1) digital currency: improve the convenience of currency issuance and use, such as bitcoin and Ethernet in foreign countries, and guorenbao in Chinafrom the use of physical transactions, to physical currency and credit currency, and then to the rise of bitcoin network, more and more people are aware of the distributed ledger blockchain technology behind it, and graally apply it in many scenarios other than digital currency
(2) cross border payment and settlement: realize point-to-point transaction, rece intermediate fees
transfer and payment. At present, the most mature application of blockchain technology is payment and transfer. Blockchain technology can avoid complicated systems, save the process of inter-bank reconciliation and review, and accelerate the settlement speed; virtual currency can rece transaction costs without the intervention of clearing house. Different countries have different clearing proceres. It takes two or three days for a single remittance to arrive, which is inefficient and accounts for a large proportion of funds in transit. No longer through the third party, through the blockchain technology to form point-to-point payment. By eliminating the link of the third-party institutions, we can make full day payment, real-time payment, withdraw cash quickly and rece the hidden cost, which helps to avoid the capital risk. It is timely and convenient
(3) bills and supply chain financial business: rece human intervention, rece costs and operational risksvalue transfer between point-to-point, control and verify physical bills or central system; Intermediaries will be eliminated and human intervention reced. With the improvement of efficiency, financing channels are more unblocked, risks are lower, and multiple parties benefit
(4) securities issuance and Trading: realize quasi real-time asset transfer, accelerate the speed of transaction clearing
the application of blockchain technology can make the process of securities trading more concise, transparent and fast, rece the plication of IT system, and improve the efficiency of market operation. For stocks, blockchain can eliminate paper and pen or electronic form records, rece human errors in trading, and improve the transparency and traceability of trading platform. Citigroup and Nasdaq cooperate to promote blockchain applications
(5) customer credit investigation and anti fraud: rece the cost of legal compliance, prevent financial crimes
the customer information and transaction records recorded in the blockchain help banks identify abnormal transactions and effectively prevent fraud. The technical characteristics of blockchain can change the existing credit reference system, and store the data of customers with bad records in the blockchain when the bank concts "know your customer" (KYC)
equity crowdfunding:
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to know the difference between them, we need to know the definition of them first
digital currency: short for digiccy, which is the abbreviation of "digital
currency", is an alternative currency in the form of electronic currency. Both digital gold coin and cryptocurrency belong to digiccy
blockchain: blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is essentially a decentralized database, also known as the trust machine
from the above definition, we can know that blockchain is a technology, and digital currency is a kind of virtual currency
digital currency is not equal to blockchain
many people will understand blockchain as blockchain. Here I want to correct that digital currency is not equal to blockchain. Digital currency is only an application of blockchain, and some digital currencies may not be applied to blockchain technology.
for example, Sunzi asked Li Zi to borrow 100 yuan, but Li Zi was afraid that he would default, so he asked the village head to do notarization and add the account. This is called centralization. But if you don't ask the head of the village, you can shout "I'll lend my grandson 100 yuan! Please put it in the account book. "This is called decentralization. In the past, the village head was highly respected and had a good command of the accounts of the whole village. Everyone kept their money with him. This was the past trust in centralization. Now, everyone is worried that the village head will secretly misappropriate everyone's money. What should we do? So everyone sent an account book to everyone. Anyone who transfers money between them releases information through the loudspeaker. After receiving the information, everyone records the transaction in their own account book. This is called decentralization. With distributed ledgers, it doesn't matter if Lao Zhang or Lao Li's ledgers are lost, because Lao Zhao, Lao Ma and other families have ledgers
digital currency is abbreviation of digital currency. It is an alternative currency in the form of electronic currency. Both digital gold coin and cryptocurrency belong to digiccy. Blockchain technology service upgrade technology
blockchain technology has been questioned by the collapse of the centralized currency exchange, but its potential to solve the trust and centralization problems of the existing information architecture has attracted a lot of attention. Blockchain technology first gained great popularity in the field of bitcoin and digital currency. It uses a single shared ledger to store information. It is no longer to let a single central organization obtain the account book, but to obtain multiple copies of the same distributed account book by different nodes in the peer-to-peer network. Shenzhen yuanzhongrui blockchain technology adopts advanced encryption technology to ensure that any new information in the account book can not be tampered, unless it meets some preset parameters. Moreover, this kind of Ledger has stronger defense against external attacks, such as network attacks, because this decentralized system does not have a single point of failure with high cost of centralized information architecture. At the same time, all trusted nodes can affect any modification of the ledger, provided that they meet the specific preset parameters. These changes will be immediately reflected in the ledger, and all trusted nodes can obtain relevant data to make correct decisions. It can also adjust the design of the distributed ledger, create a hierarchical system within the architecture, and configure appropriate access rights and different levels of authority
blockchain and distributed ledger technology are concive to change the management mode of land registration. At present, the credibility of the real estate market is at the lowest level, which is attributed to the inefficient and opaque property registration system. The system relies on the centralized acquisition of land registration and corresponding property transaction information. Using distributed ledger technology to obtain, manage and modify these information can ensure that the public will not be infringed by land transaction fraud. Similarly, distributed ledger can simplify and integrate cross instry and cross regulatory compliance process, because it contains real-time compliance information needed by government departments, banks, investors and other third parties. By integrating data points of multiple projects and providing feedback on beneficiaries' project participation, we can better track the implementation of social welfare plans
at present, the biggest problems of technology development include: transformation cost of unique data storage system, data reliability verification of network nodes or all levels, privacy and security dimension of decentralized data acquisition, and revision of information technology act. What's important is that blockchain technology will change the way the government interacts with citizens, and this huge change is bound to be resisted by civil servants. These are all possible problems. We should take immediate action to formulate a regulatory framework to guide application development in addition to adopting blockchain technology.
taking bitcoin as an example, it does not have an entity form, but exists in a special account book. All bitcoin transactions are recorded in the ledger. Through the transaction records, we can calculate the number of bitcoins owned by each user. If a person owns bitcoin, it means that he can find the relevant transaction records in the ledger
the ledger mentioned here is a software that we can download from bitcoin's official website, and the underlying technology used in this software is blockchain. In order to facilitate understanding, we usually say that blockchain is the ledger
the reason why blockchain is used as the underlying technology of ledger is to realize the feature of digital currency decentralization. It can be said that the starting point of a series of problems and solutions of digital currency comes from decentralization
2. Blockchain is a technology to ensure the safe use of digital currency. As we all know, blockchain technology has the characteristics of encryption and non tampering, which can rece the probability of errors in the use of digital currency to 0. Because digital currency requires higher encryption, it must be supported by blockchain technology. At present, not only many instries in China are using blockchain technology, but also many foreign countries are actively using blockchain technology.