Blockchain trust machine

1. blockchain technology is considered to be the next generation of disruptive core technology after steam engine, power and Internet. If the steam engine has released people's proctivity, the power has solved people's basic living needs, and the Internet has completely changed the way of information transmission, then the blockchain, as a machine for building trust, may completely change the way of value transmission of the whole human society. In the past, relying on reputation, century old stores and authoritative institutions, blockchain has established a new way of trust by using technology, which can be quantified and realized from the perspective of technology. Therefore, blockchain has become the cornerstone of the next trust. The core revolutionary feature of blockchain is to change the backward credit mechanism for thousands of years
blockchain technology is the underlying technology of bitcoin. Bitcoin has been running without any centralized organization operation and management. Later, bitcoin technology was abstracted out, which was called blockchain technology or distributed ledger technology. It can be said that bitcoin is the first application of blockchain and will be extended to more and more instries in the future
bitcoin is the leader of virtual currency and has the reputation of digital gold. Its value lies in its network. We can connect to the global payment network in real time. It can send large or small amount of funds to any person, any place, any time, for any purpose, and complete the transaction without obtaining or sharing any person's private information. Using utomarket makes digital currency transaction easier.

2.

Blockchain is an important concept of bitcoin. It is essentially a disintermediated database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains the information of a bitcoin network transaction, which is used to verify the effectiveness of its information (anti-counterfeiting) and generate the next block

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in a sequential way according to the time sequence, and it can not be tampered with and forged by cryptography

broadly speaking, blockchain technology uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, and uses cryptography to ensure the security of data transmission and access It is a new distributed infrastructure and computing method to program and operate data by using intelligent contract composed of automated script code

extended data:

the evolution mode of blockchain is as follows:

& 9642; Blockchain 1.0 - digital currency

▪ Blockchain 2.0 - digital assets and smart contracts

▪ Blockchain 3.0 - Implementation of distributed applications in various instries

blockchain features:

1. Disintermediation. Due to the use of Distributed Accounting and storage, there is no centralized hardware or management organization in the system, the rights and obligations of any node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system

2. Openness. The 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. Autonomy. Blockchain adopts 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

The information can not be tampered with. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the 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, the data interaction does not need to be trusted (the program rules in the blockchain will judge whether the activity is effective). Therefore, the counterparties do not need to make the other party trust themselves by disclosing their identities, which is very helpful for the accumulation of credit

3. Introction to seven core technologies of blockchain operation on January 15, 2018
1. Blockchain links
as the name suggests, blockchain is a chain composed of blocks. Each block is divided into block head and block body (including transaction data). The block head includes the prevhash value (also known as hash value) of the previous block used to realize the block link and the random number (nonce) used to calculate the mining difficulty. The hash value of the previous block is actually the hash value of the head of the previous block, and the random number calculation rule determines which miner can obtain the right to record the block
2. Consensus mechanism
blockchain is accompanied by the birth of bitcoin, which is the basic technology architecture of bitcoin. Blockchain can be understood as an Internet-based decentralized accounting system. A decentralized digital currency system like bitcoin requires the consistency of accounting of honest nodes without a central node, which needs blockchain to complete. Therefore, the core of blockchain technology is a consensus mechanism to reach a consensus on the legitimacy of transactions between indivials without mutual trust without central control
there are four main types of consensus mechanisms in blockchain: pow, POS, dpos and distributed consistency algorithm
3. Unlocking script
script is an important technology to realize automatic verification and contract execution on blockchain. Every output of every transaction does not point to an address in the strict sense, but to a script. A script is like a set of rules that constrain how the receiver can spend the asset locked on the output
the validation of transactions also depends on scripts. At present, it depends on two kinds of scripts: Lock script and unlock script. Locking script is a condition added to the output transaction, which is realized by a script language and located in the output of the transaction. The unlocking script corresponds to the locking script. Only when the conditions required by the locking script are met can the assets corresponding to the script be spent, which is located in the input of the transaction. Many flexible conditions can be expressed by script language. Interpretation script is similar to the "virtual machine" in our programming field, which runs in every node of the blockchain network in a distributed way
4. Transaction rules
blockchain transaction is not only the basic unit of a block, but also the actual effective content recorded by the blockchain. A blockchain transaction can be a transfer, or the deployment of smart contracts and other transactions
as far as bitcoin is concerned, a transaction refers to a single payment transfer. The transaction rules are as follows:
1) the input and output of the transaction cannot be empty
2) for each input of a transaction, if its corresponding utxo output can be found in the current transaction pool, the transaction will be rejected. Because the current transaction pool is the transaction not recorded in the blockchain, and each input of the transaction should come from the confirmed utxo. If it is found in the current trading pool, it is Shuanghua trading
3) for each input in a transaction, the corresponding output must be utxo
4) each input unlocking script must verify the compliance of the transaction together with the corresponding output locking script
5. Transaction priority
the priority of blockchain transaction is determined by the blockchain protocol rules. For bitcoin, the priority of a transaction to be included in a block is determined by the time when the transaction is broadcast to the network and the amount of the transaction. With the increase of transaction broadcast time on the network and the increase of transaction chain age, the priority of transaction will be improved and eventually be included by the block. For Ethereum, the priority of the transaction is also related to the transaction fee that the publisher is willing to pay. The higher the transaction fee that the publisher is willing to pay, the higher the priority that the transaction is included in the block
6. Merkle proof
the original application of Merkle proof is bitcoin, which was described and created by Satoshi Nakamoto in 2009. Bitcoin blockchain uses Merkle proof to store transactions in each block. So that the transaction can not be tampered with, but also easy to verify whether the transaction is included in a specific block
7. RLP
RLP (recursive length prefix) is one of the main encoding methods of object serialization in Ethereum. Its purpose is to encode the sequence of arbitrary nested binary data.

4.

(1) Technical level. Since 2007, distributed computing has affected technical developers, so it is normal for bitcoin to appear in the field of virtual currency

(2) hardware level. The popularity of PC servers and the exponential growth of computing power

(3) commercial level. The three characteristics of blockchain, namely, decentralization, distrust and extremely difficult forgery, just meet the needs of recing the trust cost and speeding up the transaction speed in financial fields such as stock trading and bank settlement

(4) political level. Blockchain can rece the transaction cost to a certain extent, but the anonymity and untraceability of blockchain cause huge political risk

[blockchain as the underlying technology of bitcoin was proposed at the end of 2008]

< p class = ikqb_ image_ Blockchain is mentioned in this book

5. In the traditional case, no matter the size of the system behind a database, the database is like a large ledger. For example, the database of a certain treasure is like a big account book, which records how much money a user has and how much money b user has. If a user pays one yuan to B user, a treasure will add one yuan to B user's account and subtract one yuan from a user's account. Therefore, the change of database can also be regarded as an accounting behavior

we usually think that the one who maintains the system is the one who manages the database, and other users have no right to participate. Just like the users of a certain treasure can not participate in the specific bookkeeping behavior

but blockchain subverts the tradition and lets every user in the system participate in it

blockchain is like a large total account book. Every user in the system can participate in competitive bookkeeping. In a certain period of time, the system will find the fastest and best users among competitors. The user writes the data changes in this period to a block, just like writing to an account page, and copies this account page to all other users in the system for backup, completing the whole action. In the next period of time, every node in the system has a of the complete ledger

since each block data is linked together through cryptography technology, we call it "blockchain" or "distributed ledger technology"

blockchain, let the whole people participate in bookkeeping. Because there is no specific bookkeeper in the system, any part of the nodes in the system will not affect the operation of the system if they are lost or destroyed. It is safer for all people to keep accounts. The system stipulates that the same number of accounts with the largest number are true accounts, and a small number of accounts that are inconsistent with other users are false accounts. This makes it difficult for a blockchain with enough nodes to be attacked and tampered with. These nodes are distributed in any corner of the Internet. Unless you are God and can control most computers in the world, you cannot tamper with them. Therefore, blockchain is considered to be the most secure way of data management in history. National bookkeeping is more efficient. Because there is no centralized intermediary organization, it can run automatically through pre-set proceres, which can greatly rece costs and improve efficiency, and ensure that the process and content of account records are open and transparent

bitcoin is only an experimental application of blockchain technology in the field of payment. Blockchain can also be used in a broader field, including medical treatment, supply chain, Internet of things, security authentication, social networking and artificial intelligence The economist called blockchain "the trust machine" and believed that it would have a huge and far-reaching impact on global finance and even social structure

to sum up in one sentence, blockchain technology is a way that enables all participants in the system to work together to record and maintain a reliable data log under the environment of multi-party without mutual trust through cryptography technology

bitcoin, blockchain content publishing platform decent and lightcoin all use blockchain technology, and anyone can participate in it in theory.