Block chain from the point of view of data: I think it is a data management system: -nosql / sql, block chain is decentralized traditional data management are centralized, a new distributed infrastructure and Calculation.
From a technical point of view: the plurality of integrated technology, forming a recording expression data storage.
Forming become a new data record, store, and a way to express new forms of data recording, storage and expression of a new data record, and storing in a way to express
VS traditional database block chain:
1. The operation position of the support / storage / usage patterns
Is a database management system, database management systems only support operations add select data, does not support the delete and update data operations on each client using this library memory / hard drive data stored in the database. This database system that is the client, but also a server. The central point of the database does not exist, he said. (Jointly maintained by the participants in the system, collective defense)
Common database management systems: support data storage crud all operations in the database server (also known as the central point), is inseparable from the center point of operational data - server, you need to download the client connection on the server.
2. Data Structure
Block chain: the data structure is a block of time between blocks connected in the order, a combination of chain data structure, stored in the memory? ? to be confirmed;
Data structures are: on the hard disk, the file stored in the indexed file system storage;
Cryptography: to ensure the transmission and access security, is to prevent theft;
Consensus: in order to generate data; algorithm uses distributed nodes consensus algorithm to generate and update data; // each node comply with this algorithm.
Smart Contract: using intelligent automation contract by the composition of the script code to program and manipulate data
Block chain operating principle:
To get to know the first data block to be stored, and block
In bitcoin block chain, when the transaction is generated through a node or purse, the deal needs to be transmitted to their
It node for verification. Practice is transaction data through encryption and digital signature obtained through the Hash function on behalf of a bunch of this post
Easily after only Hash value, then the Hash value broadcast (Broadcast) block chain other bits of credits to the network
Participating nodes for verification.
Specific process is as follows:
A new transaction generating a sum
B sum generating a new transaction, will first block chain to be broadcast to other network nodes participating
C each node the number of new transactions into the pen block
D each node the number of transactions pen unverified Hash values collected blocks, each block can contain hundreds or thousands of pen
transactions
E decide who will verify these transactions
F nodes are calculated effort to determine who can prove verify the transaction, the results calculated by the node to verify the fastest delivery
and easy, this is the consensus approach.
Node G acquired the right to verify the block broadcast to all nodes in the
node H fastest to complete the POW's, will own block broadcast to other nodes
J and connect each node to verify the new block
K other nodes will confirm this block contained the transaction is valid, not to be repeated to confirm spent possessed a valid digital signature
after receiving the block, then the block was officially connected to the block chain can no longer tamper with data.
L transaction verification completed
M all nodes after accepting the block, previously did not finish the job count POW blocks will fail, each node will re-establish
a block, next time continue POW calculations.
Bit block chain credits VS VS cottage credits
Bitcoin is just a scenario block chain, on the block chain, almost all of the technologies are already before bitcoins, but before Bitcoin, no one feels it can use, so that bitcoin block chain is the first successful and largest application technology.
Bit token system functions are made using credit billing currency, wherein the billing block chain portion is the technology used.
Bitcoin is an open source, the Bitcoin source code base to be amended to create the similar Bitcoin digital currency, which
Cottage currency. If you do innovative technical improvements can be called the second generation of competitive currency or coins. Usually people habitually referred to as cottage
currency.
Classification block chain technology
Classification block chain technology also with the application of all aspects of the increasingly become clear, block chain is currently divided into three categories: private chain,
public chain, chain alliance.
A private chain
refers to certain centralized control block chain. Block chain technique using only general ledger accounting is performed, it may be a well-
Division, may be personal, exclusive write access to the block chain, and the chain is not much different from other distributed storage solution.
Only the user's own node involvement, access, and use data, there are strict rights management. Because there is a certain alliance chain in
the heart of control, so it can be considered as belonging to the private chain category.
Features: Since all users have the final say, the characteristics of which data is not can not be changed for a third party is not much protection
barrier. Generally used as an internal audit. Vice president of network technology fire coins that: private chain does have a lot of scenes can dock the real
needs of the world, limited to the center easier to reach a consensus, can make transactions faster, more efficient, and can
provide a more controlled function. To the center of the block chain technology is a core value lies. If the chain does not charge private practice in
sub-trust basis using the center of the chain to public construction, the development of space will be limited.
B chain public
public block chain is the first block chain, is currently the most widely used of the block chain. It refers like credits bit block chain
completely decentralized, without any means of control block chain. Any individual or group in the world can send the transaction,
and the transaction can be obtained efficiently confirm the block chain, anyone can participate in its consensus process. Participants consensus process through
through the built-in cryptography technology and economic incentives to maintain the security of the database.
Features: completely open, uncontrolled, rely on encryption to ensure security.
C chain Alliance
A group designated by the internal multiple preselected nodes accounting people, generated for each block determined by all of the preselected nodes,
other access node can be involved in the transaction, but the billing process but asked (or hosted accounting essence just become distributed remember
how many accounts, pre-selected node, determine how each block by a major accounting risk point of the block chain), any other person
may be limited by the query block chain open API.
Participating nodes block chain is a good choice in advance, between nodes is likely to have a good network connection. On this block chain may
otherwise non-consensus algorithms workload proof, such as a link between the establishment of a block of 100 financial institutions, regulations
set to be more than 67 institutions agreed to be considered to reach a consensus.
Features: Alliance chain can do a good connection between the nodes, requires minimal cost will be able to maintain the operation, provide rapid
transaction processing and low transaction costs, have good scalability (but scalability as nodes increase will decline), data can be
to have some privacy. Union chain also means that the application will not block chain is too wide, the lack of dissemination of Bitcoin network
effect
Classification block chain project
Underlying chain: Ethereum, Qtum, Bitshaes, Waves , Aeternity, EOS, Tezos
Distributed Storage: IPFS, Sia, Maidsafe, Storj
distributed computing: iExec, Golem, Elastic
things: IOTA
Cross chain: Bancor, infinite, COSMOS
anonymous Currency: Digital Cash, Zcash, Komodo
asset management: Melonport, Iconomi, Taas, blockchain Capital, DigixDAO
loans: Humaniq, Wetrust
game: Firstblood, GameCredits, Bitcrystals
pay (C-terminus wallet, business clients): Omesigo, Plutus, Im token , Blockpay
debit card: Tokencard, Tenx
remittance: cloaking, Ripple, Stella
content sharing: Decent, Steemit, BAT, Synereo , SingularDTV
predict market: Truthcoin, Augur, Gnosis
social communication: Status, Matchpool
development tools: Lisk, Stratis
Knowledge : Lunyr
crowdfunding platform: Wings, Virtual Accelerator, Swarm
there is proof: Factom
authentication: Civic
Recruitment platform: ChronoBank
Points: Incent
The concept of intelligent contracts
Nature: a piece of computer program
Intelligent contract is a commitment defined in digital form, commitment and control of digital assets include the right to contract the participants agreed
And obligations, performed automatically by the computer system. "
"A computer program is not just a smart contract procedures can be performed automatically, which is itself a system participant, docking
Respond to received information, may be received and stored value, and value information may be transmitted outward. This program is like a
A person can be trusted, can temporary custody of assets, always Follow the rules in advance.
Scene Intelligent contract can be applied very widely, such as rent lease, CFDs, token system, savings wallet, crop
insurance, financial lending, set up wills, securities registration liquidation, and other gambling issue;
work theory of "intelligent contract delays not achieved, an important reason is because of a lack of support programmable digital contract
system and technology emerge block chain technology solves this problem, not only supports programmable contract, but also to the center
of, can not be tampered with, the process can be transparent tracking, etc., suitable for natural intelligence contracts. Therefore, it can be said, intelligent contract
is one of the characteristics block chain technology. "
Private and public asymmetric encryption
The private key is used to decrypt and signature, is for own use; public disclosure by me, for encryption and authentication signature, is for others to use.
As we have online bank transfer under the same public key is our bank card number, the private key is our bank card password, of course, than our private bank card 6
complex multi-digit password, in which the actual transfer, from the private to the signature role, to prove that the deal is up to you to authorized
true. Any person who has the hands of two keys, one of which only you know, called "private", and
one may be available to the public, called "public key"; by the private key encryption, public key must be decrypted, even their own
private key is also no solution. Public key can be generated by more than the private key.
Asymmetric encryption: encryption and decryption algorithm is not the same.
51% of attacks will destroy confidence in the Bitcoin system:
Attacks will change the main chain, so that other fork are invalid, this changed.
Listed bit credits essentially a block chain, if bifurcation occurs, the longest bifurcated default is true, continue to add later.
Virtually any miners dug new block can be constructed by false block to attack, but a direct consequence of bifurcation, it
The essence of this is to say the attack is through hard fork to achieve their own ends.
Why is it called 51 attacks, that is because the bifurcation other miners will not recognize the new chain, count only force more than 51%
To dig sum of money other people faster, ensure that the longest chain in order to become the backbone.
So, just launched 51 attacks, will inevitably lead to the bifurcation, we will certainly be found, there is someone on the Internet that secretly mining pool
Attack, we do not know, it might do? He cited the example was confirmed the attack but is 0, essentially a
51 failed attacks.
For more than 51% of the grasp force of people counted, 51 attacks will cause you to lose confidence in Bitcoin, What are the benefits for himself
It? As a vested interest, he wanted to do everything possible to maintain this system should be. We would not have the ability to launch and want to launch
Not competent, Nakamoto design of this system, the use of this feature is human nature to maintain the normal operation of the system.
But the real count 51% of the force in the event of attack, the consequences will be very serious, but 51% of attacks paradox, making it difficult to actually
To occur unless madman or lunatic countries