Blockchain currency Technology
blockchain is the underlying technology of bitcoin, like a database ledger, recording all transaction records. Because of its safety and convenience, this technology has graally attracted the attention of the banking and financial instry
in April 2018, a group of scholars from Oxford University announced the establishment of Woolf University, the world's first blockchain University
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data.
From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language
what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data
What are the common storage systems like
first, how to ensure high availability
the common storage system usually uses "rendancy" to solve the problem of high availability. As shown in the figure above, if the data can be copied into several copies and rendant to multiple places, high availability can be guaranteed. The data in one place is hung, and there is data in other places. For example, the master-slave cluster of MySQL is the same principle, and the raid of disk is also the same principle
two points need to be emphasized in this place are: data rendancy often leads to consistency problems
1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing, which means there is a inconsistency in reading and writing in a short period of time. This is a side effect of data rendancy
The second point is that data rendancy often reces the efficiency of writing, because data synchronization also consumes resources. If you add two slave libraries, the write efficiency will be affected. The common storage system is to use rendancy to ensure the high availability of dataso the second question, ordinary storage system, can write more
the answer is yes, for example, take this graph as an example:
in fact, MySQL can do a master-slave synchronization of al masters, master-slave synchronization of al masters, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing
how to ensure consistency in multi-point writing
the reform "Swan class" gives you more technical work
it is the birthplace of blockchain technology, and the market has confidence in it. It still maintains a stable growth under the adverse situation of major policies. Once it solves the problem of capacity expansion, the price rise can be predicted
2. Ethereum
compared with bitcoin, the advantage of Ethereum is that it has no policy problems. Although the event led to its bifurcation, the establishment of enterprise version Ethereum alliance may solve this problem. Its concept and Prospect of smart contract attract many developers to follow
the essence of community operation is that the majority decides the minority when indivials support eth
3. Zec
compared with bitcoin and Ethereum, the risk of z-coin will be greater, and its value will take a longer time to reflect. But in the long run, the value of anonymity will be one of the values that human beings generally pursue
4. BTS
bitstocks are very powerful and the system is very stable. Decentralized trading, anchoring system and so on. Although the founder bm's brain damage has hurt the community, the value of bitstocks is obviously undervalued. It is a wise choice to hold bitstocks on the cheap.
Before you go abroad, you need to exchange RMB for foreign currency. There is also a quota. With the blockchain, you can take a U-disk to go out and exchange it for local currency. The quota is unimaginable
compared with other ways, using bitcoin to remit money is much more "secret". Normal cross-border remittance will go through the examination of exchange control institutions at all levels, and the transaction records will be recorded by banks and other parties. Transactions exceeding a certain amount should be reported to relevant departments to prevent money laundering and other violations. Bitcoin, with the characteristics of globalization, is usually used as a tool for cross-border payment and remittance. As a kind of network encryption virtual currency, bitcoin has the characteristics of decentralization and anonymity,
capital flow is not easy to track, and it is easier to hide identity
wannacry blackmail virus prevention method:
1. Install the latest security patch for the computer. Microsoft has released patch ms17-010 to fix the system vulnerability of "eternal blue" attack. Please install this security patch as soon as possible; For Windows XP, 2003 and other machines that Microsoft no longer provides security updates, we can use 360 "NSA Arsenal immunity tool" to detect whether there are vulnerabilities in the system, and close the ports affected by the vulnerabilities, so as to avoid being infringed by blackmail software and other viruses
2. Close ports 445, 135, 137, 138 and 139, and close network sharing
3. Strengthen the awareness of network security: don't click the unknown link, don't download the unknown file, don't open the unknown email...
4. Back up the important files in your computer to the mobile hard disk and U disk as soon as possible (regularly in the future), and save the disk offline after the backup
5. It is recommended that users who are still using Windows XP and windows 2003 should upgrade to Windows 7 / windows 10 or windows 2008 / 2012 / 2016 as soon as possible.