How to apply blockchain to guarantee business review
at present, many local governments in China are promoting blockchain government application platforms, such as Chongqing's blockchain government service platform, Guangzhou's tax chain platform, Hunan Changsha's SMIC blockchain public service platform, etc
from the perspective of technical characteristics, value and domestic cases, it is very necessary.
One of the characteristics of blockchain projects (especially public chains) is open source. Through open source code, to improve the credibility of the project, so that more people can participate. But the open source code also makes it easier for attackers to attack blockchain system. In the past two years, there have been a number of hacker attacks. Recently, the anonymous currency verge (xvg) was attacked again. The attacker locked a vulnerability in the xvg code, which allowed malicious miners to add false timestamps on the block, and then quickly dig out new blocks. In a few hours, the attacker obtained nearly $1.75 million worth of digital currency. Although the subsequent attack was successfully stopped, no one can guarantee whether the attacker will attack again in the future
of course, blockchain developers can also take some measures
one is to use professional code audit services,
the other is to understand the security coding specifications and take preventive measures
the security of cryptographic algorithm
with the development of quantum computer, it will bring a major security threat to the current cryptosystem. Blockchain mainly relies on elliptic curve public key encryption algorithm to generate digital signature for secure transactions. Currently, the most commonly used ECDSA, RSA, DSA, etc. can not withstand quantum attacks in theory, and there will be greater risks. More and more researchers begin to pay attention to cryptographic algorithms that can resist quantum attacks
of course, in addition to changing the algorithm, there is another way to improve the security:
refer to bitcoin's treatment of public key address to rece the potential risk of public key disclosure. As users, especially bitcoin users, the balance after each transaction is stored in a new address to ensure that the public key of the address where bitcoin funds are stored is not leaked
security of consensus mechanism
the current consensus mechanisms include proof of work (POW), proof of stake (POS), delegated proof of stake (dpos), practical Byzantine fault tolerance (pbft), etc
POW faces 51% attack. Because POW depends on computing power, when the attacker has the advantage of computing power, the probability of finding a new block will be greater than that of other nodes. At this time, the attacker has the ability to cancel the existing transaction. It should be noted that even in this case, the attacker can only modify his own transaction, but not the transaction of other users (the attacker does not have the private key of other users)
in POS, attackers can attack successfully only when they hold more than 51% token, which is more difficult than 51% computing power in pow
in pbft, when the malicious nodes are less than 1 / 3 of the total nodes, the system is secure. Generally speaking, any consensus mechanism has its own conditions. As an attacker, we also need to consider that once the attack is successful, the value of the system will return to zero. At this time, the attacker does not get any other valuable return except destruction
for the designers of blockchain projects, they should understand the advantages and disadvantages of each consensus mechanism, so as to select an appropriate consensus mechanism or design a new consensus mechanism according to the needs of the scene
security of smart contract
smart contract has the advantages of low operation cost and low risk of human intervention, but if there are problems in the design of smart contract, it may bring greater losses. In June 2016, the Dao, the most popular funding project of Ethereum, was attacked. The hacker obtained more than 3.5 million Ethereum coins, which later led to the bifurcation of Ethereum into Eth and etc
there are two aspects of the proposed measures:
one is to audit the security of smart contract, and the other is to follow the principle of smart contract security development
the security development principles of smart contract are: to be prepared for possible errors, to ensure that the code can correctly handle the bugs and vulnerabilities; Release smart contracts carefully, do well in function test and security test, and fully consider the boundary; Keep smart contracts simple; Pay attention to the threat intelligence of blockchain and check and update in time; Be clear about the characteristics of blockchain, such as calling external contracts carefully
security of digital wallet
there are three main security risks in digital wallet: first, design defects. At the end of 2014, a user lost hundreds of digital assets e to a serious random number problem (repeated r value). Second, the digital wallet contains malicious code. Third, the loss of assets caused by the loss or damage of computers and mobile phones
there are four main countermeasures:
one is to ensure the randomness of the private key
The second is to check the hash value before installing the software to ensure that the digital wallet software has not been tampered with The third is to use cold wallet The fourth is to back up the private keyBlockchain technology is widely used. Under the integration of new technologies, the main application scenarios of blockchain include finance and insurance, intelligent manufacturing, intelligent environmental protection, energy and power, health care, ecation, culture and innovation, smart city, social welfare, agriculture and many other fields
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blockchain + finance
blockchain can help financial institutions solve problems such as trust and data sharing
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blockchain + right art
Tianhe Guoyun's blockchain right system
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3. Blockchain + government
in statistics, voting, budget management and other aspects, blockchain can rece costs, improve efficiency, and increase transparency, so as to prevent the risk of failure of centralized system
4. Blockchain + insurance
fraud identification and risk prevention: by placing insurance claims under an unchangeable general ledger, blockchain helps to eliminate the common sources of fraud in the insurance instry
property insurance and accidental injury insurance: policies and shared ledgers recorded in the form of smart contracts can improve the efficiency of property insurance and accidental injury insurance
Health Insurance: blockchain technology enables medical records to be encrypted and shared among health service providers, thus improving the interoperability of the health insurance ecosystem
Reinsurance: the information security of reinsurance contracts on the blockchain platform can be ensured through the form of smart contracts, which can rece the amount of information and simplify the payment process between insurers and reinsurers
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
taking the tourism instry as an example, blockchain applications mainly focus on tourism travel, tourism community reviews, digital identity management, credit consumption management, tracking pilot's professional certificate and qualification, loyalty plan of hotels and airlines, reservation management and consumption points management. In addition, blockchain also has applications in finance, games, entertainment and other fields.
Electronic contract itself is a kind of electronic data, which has security defects such as easy to tamper and delete, which is not concive to the long-term development of the service. In order to ensure the legal effect of the electronic documents and electronic contracts signed by users on the electronic contract platform, it is necessary to deposit the whole process of electronic contract signing
in the application of "legal chain" based on blockchain certificate keeping technology, the platform will archive the key links of electronic contract signing, and store the key information and data in the whole blockchain, so as to realize the whole process of electronic contract certificate keeping
in-depth study of its implementation principle, blockchain uses cryptography algorithm, specially designed data structure and multi-party consensus algorithm to solve the consistency, reliable storage and anti tampering problems of multi-party transaction records by machine algorithm, which has a strong natural relationship with electronic data storage
First of all, the electronic contract signing records are stored in a shared account book jointly maintained by multiple parties, which can not be tampered with, denied or lostsecondly, the text and elements of the electronic contract are encrypted, including the participants of the electronic contract. Only the participants can decrypt and view the data to protect the privacy of the parties
thirdly, the machine strictly implements the pre-defined rules (smart contract), and no longer relies on a single agreement with a third party. KYC service based on blockchain automatically checks and verifies the validity and identity of certificates, and ensures the authenticity of participants' identities on the basis of privacy
at present, the electronic contracts signed on our electronic contract platform have realized the distributed storage of digital fingerprints of electronic documents through blockchain technology, which further strengthens the legal effect of the platform's electronic contracts
First of all, get familiar with the characteristics of blockchain (extracted from the network):
decentralized
e to the use of Distributed Accounting and storage, there is no centralized hardware or management organization, 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
openness
the system is open, in addition to the private information of the parties to the transaction is encrypted, the data of the blockchain is open to all, and anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
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
information cannot 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, because the data stability and reliability of the blockchain are very high
anonymity
because the exchange between nodes follows a fixed algorithm, their data interaction does not need to be trusted (the program rules in the blockchain will judge whether the activity is effective by themselves), so the counterparties do not need to let each other generate trust by disclosing their identities, which is very helpful for credit accumulation
these characteristics are fundamental changes that will greatly change our lives. Bitcoin, one of its application scenarios, can completely eliminate all kinds of problems such as currency over issuance, money laundering, corruption, tax avoidance, counterfeit money and so on
in the financial field, besides bitcoin, Ali is also actively applying it to public welfare projects; Jingdong is also making some innovative financial procts