Block chain POS calculation method
POW: full name of proof of work
pos: proof of stake
both of them are the consensus mechanism of blockchain and the bookkeeping method of digital currency
the difference is:
1. POW mechanism: workload proof mechanism, that is, the proof of workload, is the requirement that must be met when generating a new transaction information (that is, a new block) to be added to the blockchain. In the blockchain network based on workload proof mechanism, the ability of nodes to obtain the correct numerical solution to generate blocks by calculating the numerical solution of random hash hash is the specific performance of node computing power
POS mechanism: the proof of rights and interests requires the certifier to provide a certain amount of ownership of cryptocurrency. The operation mode of the proof of rights and interests mechanism is that when creating a new block, the miners need to create a "currency right" transaction, and the transaction will send some coins to the miners themselves according to the preset proportion. According to the proportion and time of token owned by each node, the equity proof mechanism reces the mining difficulty of nodes proportionally according to the algorithm, so as to speed up the speed of searching for random numbersextended materials:
the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's ideas, the open source software and the P2P network on it were designed and released. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
unlike most currencies, bitcoin does not rely on specific currency institutions. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses the design of cryptography to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction
address: No.19, xitaikang Road, Jinshui District, Zhengzhou City
Jiefang Road Station on the second road - bus stop
passing buses: 67, B12, K802, k804, k808, k811, y807
Bus line: Metro Line 1, about 5.0km in total distance
1. Walk 790m from Zhengzhou Central Hospital to Tong Road Station
2. Take Metro Line 1, pass 3 stops, reach Medical College Station
3, walk 950m, reach Zhengzhou book purchasing center
bus line: Metro Line 1 → y804, about 5.4km in total distance
1 Walk about 790 meters from Zhengzhou Central Hospital to Tong Road Station
2, take subway line 1, pass 3 stops to Medical College Station
3, walk about 350 meters to Zhongyuan Road University Road Station
4, take y804 Road, pass 1 stop to university road Taoyuan Road Station
5, walk about 50 meters to Zhengzhou book shopping center
then he built a mine pool, and many people bought mining machines in his custody
he can continuously earn money from the mine pool
As an emerging technology, blockchain has attracted more and more attention. It is a new application of traditional technology in the Internet era, including distributed data storage technology, consensus mechanism and cryptography. With the establishment of various blockchain research alliances, more and more funds and personnel support related research. Hash algorithm, zero knowledge proof, ring signature and other cryptographic algorithms used in blockchain:
hash algorithm
as the basic technology of blockchain, the essence of hash function is to map a set of data of any length (limited) to a set of defined length data stream. If this function satisfies the following conditions:
(1) the calculation of hash value for any group of data is very simple
(2) it is difficult to find two different data with the same hash value
hash functions satisfying the above two properties are also called encrypted hash functions. In case of no contradiction, hash functions usually refer to encrypted hash functions. For the hash function, finding such that is called a collision. The current popular hash functions are MD5, SHA1, Sha2, Sha3
bitcoin uses sha256, and most blockchain systems use sha256 algorithm. So here's sha256< Step 1: additional filling bits. The length of the message is congruent with that of 448 mod512 (length = 448 mod512). The number of bits to be filled ranges from 1 to 512. The highest bit of the filled bit string is 1, and the rest bits are 0
Step2: additional length value. The bit length of the initial message (before filling) represented by 64 bit is appended to the result of step 1 (the low byte takes precedence)
Step3: initialize cache. A 256 bit cache is used to store the intermediate and final results of the hash function
Step 4: process 512 bit (16 word) packet sequence. The algorithm uses six basic logic functions and consists of 64 steps of iterative operation. Each step takes the 256 bit cache value as the input, and then updates the cache content. Each step uses a 32-bit constant KT and a 32-bit wt. Where WT is the packet after the packet, t = 1,2,..., 16
step5: after all 512 bit packets are processed, the output of the last packet of sha256 algorithm is 256 bit packet< In 2001, Rivest, Shamir and TauMan proposed ring signature for the first time. It is a simplified group signature, only ring members have no manager, and it does not need the cooperation between ring members. In the ring signature scheme, the signer first selects a temporary signer set, which includes signers. Then the signer can generate the signature independently by using his private key and the public key of others in the signature set without the help of others. Members of the signer collection may not know that they are included in it
ring signature scheme consists of the following parts:
(1) key generation. A key pair (public key PKI, private key ski) is generated for each member of the ring
(2) signature. The signer uses his private key and the public keys of any n ring members (including himself) to generate the signature a for the message M
(3) signature verification. According to the ring signature and message M, the verifier verifies whether the signature is signed by the member in the ring. If it is valid, it will be received, otherwise it will be discarded
ring signature satisfies the following properties:
(1) unconditional anonymity: the attacker can not determine which member of the ring generated the signature, even if the private key of the ring member is obtained, the probability is not more than 1 / n
(2) Correctness: the signature must be verifiable by all others
(3) unforgeability: other members of the ring can't forge the real signer's signature, and even if an external attacker obtains a valid ring signature, he can't forge a signature for message M
(1) anonymity. The verifier can verify that the signature is signed by a member of the group, but can't know which member it is, so that the signer can be anonymous< (2) traceability. In group signature, the existence of group administrator ensures the traceability of signature. The group administrator can revoke the signature and expose the real signer. The ring signature itself cannot reveal the signer unless the signer wants to expose or add additional information to the signature. A verifiable ring signature scheme is proposed. In this scheme, the real signer wants the verifier to know his identity. At this time, the real signer can confirm his identity by disclosing his secret information< (3) management system. Group signature is managed by group administrator, ring signature does not need to be managed, signer can only select a set of possible signers, obtain its public key, and then publish the set, all members are equalthe 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< br />
1. Technical language
Python and go are two technical languages mentioned by many companies. Learning needs to be a priority. Moreover, these two languages have great application in the technical direction outside the blockchain. For example, go is used in the background construction of large concurrent systems, and Python is used in the construction of artificial intelligence systems. So learning these two languages is a priority
2. Technical framework
master one or more of bitcoin, Eth and hyperledger. Needless to say, BTC is written in C + +. A large number of currency projects, such as lightcoin, dash, Monroe, zcash, use bitcoin technology for secondary development
eth is the representative of blockchain 2.0, which can build a variety of application classes DAPP on eth network. Now a large number of application blockchain projects are developed using eth platform
hyperledger fabric is a blockchain development platform pushed by IBM, which is mainly used for the development of alliance chain, and is the most popular alliance chain development platform at present
3, algorithm
pow (proof of work), POS (proof of rights and interests algorithm), pbft (Byzantine fault-tolerant algorithm) are all important components of cryptography in blockchain. A full understanding of these algorithms will help you to have a better understanding of cryptography when you participate in the underlying development of blockchain projects
extended data:
blockchain technology is a kind of Distributed Accounting Technology, which is characterized by decentralization, openness and transparency, so that everyone can participate in the establishment of the database, and each established data can not be tampered with, and everyone participates, The problem of trust between strangers is solved
blockchain technology has emerged. It is an accounting technology with the participation of the whole people. The transaction information and data between AB and ab are published to the public and can not be tampered with. As we all know, there is no need for any authoritative Third Party C here. In other words, everyone in the system plays the role of C, which is also called decentralization