Blockchain digital encryption technology
bitcoin, Ruitai coin, Laite coin, Ethereum and other digital cryptocurrencies all use blockchain technology
blockchain is an important concept of bitcoin, which is essentially a decentralized database and the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block.
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.
asymmetric encryption algorithm is a function that converts the original plaintext file or data into a series of unreadable ciphertext codes by using an encryption key. The encryption process is irreversible. Only holding the corresponding decryption key can the encrypted information be decrypted into readable plaintext. Encryption enables private data to be transmitted through the public network under the condition of low risk, and protects the data from being stolen and read by the third party
the core advantage of blockchain technology is decentralization, which can realize point-to-point transaction, coordination and cooperation based on decentralized credit in a distributed system without mutual trust by means of data encryption, time stamp, distributed consensus and economic incentive, so as to solve the high cost and low cost of centralized institutions Low efficiency and data storage insecurity provide solutions
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.
Osmanthus fragrans doesn't belong to Osmanthus fragrans. Cigui, also known as Huaye tree, mouse thorn; It is a plant of Ilex family. Evergreen shrubs or small trees, landscaping tree species. It is mainly distributed in the middle and lower reaches of the Yangtze River in China
There are four groups of Osmanthus fragrans, namely Dangui, Jingui, Yingui and sijigui. Among them, Osmanthus fragrans, Osmanthus fragrans and Osmanthus fragrans all bloom in autumn and are collectively called August osmanthus. Generally, it takes at least 10 years for Osmanthus fragrans seedlings to bloom in open field. For newly transplanted seedlings, it is not allowed to apply fertilizer too early. Sowing seedlings, after two years of cultivation, the next spring can be transplanted, flowering period in ten yearsAs 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 />