Authority control of blockchain encryption

1. In view of the security characteristics and shortcomings of the existing blockchain technology, we need to build a security system around the physical, data, application system, encryption, risk control and other aspects to improve the security performance of the blockchain system as a whole
1. Physical security
the network and host running the blockchain system should be in a protected environment. According to the regulatory requirements of specific business, the protection measures can be used to protect the physical network and host by means of VPN, firewall, physical isolation, etc
2. Data security
in principle, the data exchange between nodes of the blockchain should not be transmitted in clear text. For example, asymmetric encryption can be used to negotiate key, and symmetric encryption algorithm can be used to encrypt and decrypt data. The data provider should also strictly evaluate the sensitivity and security level of the data, decide whether to send the data to the blockchain, whether to desensitize the data, and adopt strict access control measures
3. Application system security
application system security needs to start from the aspects of identity authentication, authority system, transaction rules, anti fraud strategy, etc.
relevant personnel, transaction nodes and transaction data involved in application operation should be controlled in advance and auditable afterwards. Taking financial blockchain as an example, consensus algorithm with stronger fault tolerance, anti fraud and higher performance can be adopted to avoid joint fraud of some nodes
4. Key security
to encrypt the communication data between the blockchain nodes and the key to encrypt the data stored on the blockchain nodes, the plaintext should not exist on the same node, and the private key should be properly saved by the encryption machine. When the key is lost or leaked, the system can identify the relevant records of the original key, such as account control, communication encryption, data storage encryption, etc., and implement response measures to make the original key invalid. The key should also be managed strictly in the life cycle, and should not be permanently valid. It needs to be replaced after reaching a certain time cycle
5. Risk control mechanism
there should be careful detection measures for the network layer, host operation, data access of application system, transaction frequency and other dimensions of the system. For any suspicious operation, alarm, record and verification should be carried out. If illegal operation is found, loss assessment should be carried out, remedial measures should be taken at the technical and business levels, and security measures should be strengthened, And trace the source of illegal operation to prevent further attacks

Article source: white paper on blockchain technology and application development in China

2. Blockchain encryption algorithm
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.

3.

1.1. Introction

practitioners in the computer instry should be very familiar with the word hash. Hash can realize the mapping of data from one dimension to another, and hash function is usually used to realize this mapping. Generally, y = hash (x) is used in the instry. The hash function can calculate a hash value y by calculating X
hash function characteristics in blockchain:

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function parameters are string type

fixed size output

is computationally efficient

collision free means that the conflict probability is small: X= y => hash(x) != Hash (y)

hide the original information: for example, the verification of transactions between nodes in the blockchain only needs to verify the information entropy of the transaction, and does not need to compare the original information. The nodes do not need to transmit the original data of the transaction, only the hash of the transaction, Common algorithms include Sha series and MD5

1.2. Hash is widely used in blockchain. One of them is called hash pointer
hash pointer, which means that the value of the variable is calculated from the actual data and points to the actual data location, That is, it can not only represent the actual data content, but also the storage location of the actual data. The figure below shows the schematic diagram of hash pointer

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4. Jinwowo network believes that privacy protection is the advantage of blockchain. We use cryptography and distributed structure to protect privacy
jinwowo will use blockchain technology to promote the legalization of big data business. The encryption of blockchain technology can ensure that the privacy of data sources can be better protected while big data is called.

5. Absolute privacy encryption means that the addresses of both sender and receiver can not be identified and tracked, the content of the transaction is fully protected, the user's privacy is absolutely protected, but it also increases the chance of abuse by criminals. In reality, in order to meet the regulatory requirements of enterprises, especially the financial system, cryptocurrency, which has complete privacy for the public and indivials, and accountability privacy for regulatory and audit institutions, will graally become the mainstream. Abe / Abbey coin has the ability of different privacy levels, which can meet the needs of indivials in terms of privacy, as well as regulatory or corporate accountability.

6. First of all, these two are virtual assets. The price of these two kinds of digital currency, or a specific price of digital currency, is determined according to the market situation
the details of these two digital assets are as follows
bitcoin (bitcoin: bitcoin) was originally a kind of network virtual currency, which can buy real-life goods. It is characterized by decentralization, anonymity, and can only be used in the digital world. It does not belong to any country or financial institution, and is not subject to geographical restrictions. It can be exchanged anywhere in the world. Therefore, it is used as a money laundering tool by some criminals
the full name of NMC is "new media chain", the Chinese name is media chain, and the former domain name currency (also referred to as NMC) is two completely different currencies. NMC is the circulating currency of three decentralized application platforms: coin call [blockchain information community portal], coin search [blockchain network query tool], ncoin [digital currency exchange]. However, the prices of these two kinds of digital currencies will fluctuate with the market, which can not guarantee a development prospect. If the current price is concerned, bitcoin will be a bit higher.

7. Think too much... Take sha256 for example, the probability that you will collide with the private key is probably equivalent to finding a special atom from all the observable atoms in the universe. It is equivalent to winning millions of grand prizes in a row. This has nothing to do with IQ. This encryption method is barbaric and effective, not high-tech
in the future, blockchain encryption can be said to be cracked. Of course, it's not the current computer system, it's the quantum computer. Once this thing is mass proced, the blockchain will be abandoned.