Encryption and storage of data on blockchain

1. In short, the data of the blockchain is formally stored in the blockchain through the formula algorithm process of the block. All nodes in the whole network express that they accept the block, and the way to express acceptance is to make the random hash value of the block the latest block hash value. Xingqun manufacturing will be extended based on the blockchain.

2. 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

3. The relationship between blockchain and big data storage is as follows:
first, data security: blockchain makes data flow "at ease"
with its trustworthiness, security and non tamperability, blockchain liberates more data. A typical case is used to illustrate how blockchain promotes the generation of big data for gene sequencing. Blockchain sequencing can use the private key to limit access rights, so as to avoid the legal restrictions on indivial access to gene data, and use distributed computing resources to complete the sequencing service at low cost. The security of blockchain makes sequencing an instrialized solution, realizing global scale sequencing, thus promoting the massive growth of data< Second, data open sharing: blockchain guarantees data privacy
the government has a large number of high-density and high-value data, such as medical data, population data, etc. The opening of government data is the general trend, which will have an inestimable impetus to the development of the whole economy and society. However, the main difficulty and challenge of data opening is how to open data while protecting personal privacy. Data desensitization technology based on blockchain can ensure data privacy and provide a solution for data opening under privacy protection. Data desensitization technology mainly uses hash processing and other encryption algorithms. For example, enigma based on blockchain technology can protect the privacy of data and eliminate information security problems in data sharing by computing data without accessing the original data. For example, employees of a company can safely open the path to access their salary information and jointly calculate the average salary within the group. Each participant can know his or her relative position in the group, but he or she knows nothing about the salaries of other members< The schematic diagram of data hash desensitization processing
3. Data storage: blockchain is a kind of database storage technology that can not be tampered with, full history, strong endorsement
blockchain technology, through all nodes in the network participate in the calculation together, and verify the authenticity of their information to achieve the consensus of the whole network, it can be said that blockchain technology is a specific database technology. So far, our big data is still in a very basic stage. The data based on the consensus of the whole network and the reliable blockchain data are tamperable and historical, which makes the quality of the data gain unprecedented strong trust endorsement, and also makes the development of the database enter a new era< Data analysis: blockchain ensures data security
data analysis is the core of realizing data value. In data analysis, how to effectively protect personal privacy and prevent core data leakage has become the primary consideration. For example, with the application of fingerprint data analysis and the popularization of genetic data detection and analysis, more and more people worry that once personal health data is leaked, it may lead to serious consequences. Blockchain technology can prevent this kind of situation through multi signature private key, encryption technology and secure multi-party computing technology. When the data is hashed and placed on the blockchain, the use of digital signature technology can enable those authorized people to access the data. The private key not only ensures the privacy of data, but also can be shared with authorized research institutions. The data is stored on the decentralized blockchain and analyzed without accessing the original data. It can not only protect the privacy of the data, but also provide it to the global scientific research institutions and doctors for sharing. As the basic health database of all mankind, it will bring great convenience to solve the sudden and difficult diseases in the future
v. data circulation: blockchain protects the rights and interests related to data
for valuable data assets of indivials or institutions, blockchain can be used to register them. Transaction records are recognized, transparent and traceable throughout the network, making clear the source, ownership, use right and circulation path of big data assets, which is of great value to data asset transaction
on the one hand, blockchain can break the threat of intermediary ing data, which is concive to the establishment of a trusted data asset trading environment. Data is a very special commodity, which is essentially different from ordinary commodities. It is mainly characterized by unclear ownership and "being owned after seeing and ing", which also determines that the traditional commodity intermediary transaction method can not meet the needs of data sharing, exchange and transaction. Because the intermediary center has the conditions and the ability to and save all the flowing data, it is extremely unfair to the data procers. This threat can not be eliminated only by commitment, and the existence of this threat has become a huge obstacle to the flow of data. Based on the decentralized blockchain, it can break the threat of ing data in the intermediary center and protect the legitimate rights and interests of data owners
on the other hand, blockchain provides a traceable path, which can effectively solve the problem of data right confirmation. Through multiple nodes participating in the calculation in the network, blockchain can participate in the calculation and recording of data together, and verify the effectiveness of their information. It can not only carry out information anti-counterfeiting, but also provide a traceable path. The transaction information of each block is strung together to form a complete detailed list of transactions. The context of each transaction is very clear and transparent. In addition, when people have doubts about the "value" of a block, they can easily trace back the historical transaction records, and then judge whether the value is correct, and identify whether the value has been tampered or recorded incorrectly
with the protection of blockchain, big data will naturally become more active
the tokens of crowdfunding projects on coin Ying China platform are all developed based on blockchain technology, and relevant information will be recorded on the blockchain.

4. Encryption code. Every few minutes, a new block is generated, which stores different information and consists of different passwords (double keys).

5. 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.

6.

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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7. Big data and blockchain are two independent things, which do not have to be used
in fact, only high-level security data can be used for blockchain development, and most companies do not have this requirement. It can be understood that there are so many companies in the world, only a small part needs to use big data technology, and a smaller part needs to use blockchain technology. These two parts can intersect but do not include
for companies that normally use big data, there are non relational databases like HBase, mongodb, hive, Mr, spark and so on in terms of storage and processing, which have nothing to do with blockchain.

8. Blockchain can encrypt and store certificates to ensure data security
the Internet makes our life more convenient, but it also brings a series of problems and challenges about data security. Under the wave of digitalization, data security may become the core competitiveness, and under the momentum of vigorously developing blockchain in our country, it will become the general trend for blockchain to ensure data security
through self-developed blockchain technology and invention patents, yibaoquan has launched "blockchain + full evidence chain + preservation chain", which effectively ensures data security and judicial compliance. Through DES, SHA512 and other encryption algorithms, as well as time stamp service and pbft consensus algorithm, the work data is encrypted to help users encrypt and store the electronic data on the blockchain at the first time, fully guaranteeing the originality of the data stored in the blockchain and effectively preventing tampering.

9. The core advantage of blockchain is decentralization. Through the use of encryption algorithm, tree structure and consensus mechanism, trust relationship is established in decentralized distributed network, data distributed multi node encrypted storage is realized, and an open, transparent, tamperable, verifiable and traceable technology system is created, so that each node can store certificates synchronously and supervise together, It can effectively solve the problems of poor reliability and low security in the centralized mode
in Internet cases, electronic evidence is difficult to keep, collect and notarize. By using blockchain technology, easyprovision can solve the whole link trustworthiness problems of electronic evidence, such as generation, storage, notarization and evidence proof; After being linked, each judicial node in the security chain is used to ensure the data's trustworthiness and security; In litigation, evidence goes directly to the Internet court to improve the efficiency of rights protection.