Hash algorithm and blockchain Technology
blockchain is a new computing paradigm and distributed infrastructure, which uses fast chain data structure, distributed node consensus algorithm, cryptography and intelligent contract based on automated script code to proce, verify, store and transmit data. It can also be said that blockchain is a distributed ledger technology, which can provide decentralized trust mechanism in non trust environment, so that multi-party participants can conct secure trust transactions without intermediaries
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
blockchain refers to the technical solution of collective maintenance of a reliable database through centralization and distrust in the past, and it is a technical way for the whole people to participate in bookkeeping. Previous bookkeeping methods were all centralized and needed centralized intermediary, whether it was traditional government, financial institutions, notarization institutions or emerging e-commerce platform and online payment platform
in economic hypothesis, information is sufficient. In fact, it is precisely because of insufficient information that there are very large intermediaries. The existence of intermediaries increases the transaction cost and raises the transaction threshold. In essence, blockchain technology is a large-scale collaboration tool. It makes direct value transfer possible by using pure technology for the first time, and continues the trend of Internet decentralization and disintermediation. Disintermediated blockchain technology will greatly subvert the information intermediary instry
blockchain technology is the basic technology for building bitcoin data structure and encrypted transmission of transaction information, which realizes the issue and transaction of bitcoin. The core of blockchain technology is that all the current participating nodes jointly maintain the transaction and database, so that the transaction is based on the principle of cryptography rather than trust, so that any agreed parties can directly carry out payment transactions without the participation of a third party
technically, a block is a data structure for recording transactions, reflecting the capital flow of a transaction. In the system, the transaction blocks are connected to form a main chain, and all the nodes participating in the calculation record the main chain or part of the main chain
a block contains the following three parts: transaction information, hash formed by the previous block and random number. Transaction information is the task data carried by the block, including the private keys of both parties, the number of transactions, the digital signature of electronic currency, etc; The hash hash formed by the previous block is used to connect the blocks and realize the sequence of past transactions; Random number is the core of the transaction. All nodes compete to calculate the answer of the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for updating, so as to complete a transaction.
hash algorithm is a cryptographic algorithm that can only encrypt, but not decrypt. It can convert any length of information into a fixed length string
this string has two characteristics:
1. Even if the input value changes only a little, the output hash value will be very different
2. Only exactly the same input value can get exactly the same output value
3. There is no rule between the input value and the output value, so the input value cannot be calculated by the output value. In order to find the specified output value, we can only use enumeration method: constantly change the input value to find the output value that meets the conditions
hash algorithm ensures that the results of bitcoin mining can not be deced reversely. Therefore, the miner's continuous operation is essentially brutally cracking the correct input value. Whoever finds the first one will get the bitcoin reward.
jinwowo group analyzes the functions of its hash algorithm as follows:
the hash value of the blockchain can uniquely and accurately identify a block. Any node in the blockchain obtains the hash value of the block through simple hash calculation, and the calculated hash value does not change, which means that the information in the blockchain has not been tampered with.
generally, y = hash (x) is used in the instry to calculate a hash value y by calculating X.
In today's era of high development of the Internet, we are using the Internet more and more frequently, which has become an indispensable and important tool in our life. In particular, the mobile phone used for Internet communication has been used as a medium. In today's era, we are using mobile payment more and more, There are more and more ways to move. So what is digital currency? What do you know about it{ But generally speaking, it is a form of money< p> Finally, for such a form of transaction, it's all for the convenience of our daily life, and it's also for serving our own broad masses of people, so we don't have to worry about the advantages and disadvantages of digital currency and mobile payment
it is suggested that netizens should stay away from bitcoin and its related things if they don't understand bitcoin. This netizen can send me a private letter and tell me what you know. I will sort out and report on it.
Hash function, also known as hash function and hash algorithm, is a method to create small digital "fingerprint" (also known as Digest) from any kind of data. What do you mean? That is to say, if you input data of any length and content, the hash function outputs a fixed length and fixed format result, which is similar to the fingerprint of the data you input. As long as the input changes, the fingerprint will change. Different content, the fingerprint obtained by hash function is different. This is the hash function
in distributed ledger, in order to ensure data integrity, hash value is used for verification. For example, a transaction or a page of ledger (that is, the concept of block) generates a summary after hashing, which means that the transaction information of the whole block cannot be tampered with (that is, the summary cannot be kept unchanged after tampering with the data)
the original definition or narrow sense of blockchain is in the form of block + chain, which is linked by hash. Each block may have many transactions, and the whole block can generate summary information through hash function, and then each block needs to record the summary information of the previous block, so that all blocks can be connected into a chain
if you change the data of a block in the history, it means that the block summary value (i.e. hash value) will change, then the hash of the previous block recorded in the next block will have to be modified accordingly, and so on. That is to say, if you want to modify the history, you need to start from that point, and then all records will have to be modified to ensure the legitimacy of the ledger, Hash function increases the difficulty of account book tampering
the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system