Blockchain bifurcation

3.

Blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

blockchain is an important concept of bitcoin. In essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:

1. The blockchain with the whole network open and without user authorization mechanism is called public chain

2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain

3. All the nodes in the network are in the hands of one organization, which is called private chain

alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain

blockchain features

1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain

2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent

3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention

4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes

5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously

4. Forking is different from ordinary upgrading. Ordinary upgrading does not affect agreement consensus before and after upgrading, and generally does not need the participation of community consensus or computing consensus. According to the modification of the protocol, bifurcation can be divided into soft bifurcation and hard bifurcation

existing definition:

[lightning definition] hard fork refers to that when the bitcoin block format or transaction format (this is the widely spread "consensus" (should be part of the agreement consensus)) changes, the UN upgraded node refuses to verify the blocks proced by the upgraded node, but the upgraded node can verify the blocks proced by the UN upgraded node, Then we continue the chain that we think is right, so we divide it into two chains< A permanent divergence in the block chain, commonly occurs when non upgraded nodes can't validate blocks created by upgraded nodes that follow new consensus rules, The UN upgraded node can verify the blocks proced by the upgraded node, and the upgraded node can also verify the blocks proced by the UN upgraded node<

a temporary fork in the block chain which commonly occurs when miners using non upgraded nodes vialate a new consensus rule their nodes don't know about.

I don't think we can say which definition is right or wrong. The specific definition can be summed up according to the differences between the two that have been widely agreed in the community, and it doesn't need authority to specify

hard fork: without forward compatibility, the previous version will be unusable and need to be upgraded

soft fork: it has good compatibility, at least some functions of previous versions are available, and can not be upgraded

hard branching: at the level of blockchain, there will be two branching chains, one old chain and one new chain

soft bifurcation: there are no forked chains at the level of blockchain, but only the blocks that make up the chain, including new blocks and old blocks

hard forking: it is necessary to agree with the forking upgrade at a certain time point, and those who do not agree will enter the old chain

soft bifurcation: for quite a long time, it is allowed to continue to use the original version to generate old blocks and coexist with new blocks without upgrading

5. After the release of the new consensus rules, some nodes that have not been upgraded cannot verify the blocks proced by the upgraded nodes, and usually hard bifurcation occurs.

6. Hard bifurcation is caused by the unacceptable permanent divergence of blockchain, while soft bifurcation is caused by the acceptable divergence of blockchain. The emergence of hard bifurcations means the emergence of a blockchain that cannot accept the new consensus mechanism. This blockchain is equivalent to the old version of the system, while the new version accepts the new consensus mechanism. Although the two versions are not different, they are still interrelated. The block nodes caused by soft bifurcation are compatible with the new consensus mechanism, and will not form another block chain. Hard and soft bifurcations are common in coin circles. In addition to currency speculation, blockchain can be applied in many places, including medical care, insurance, ecation, food, etc. I know a company specializing in blockchain development, Xuanling technology. Their evaluation in the instry is not bad.

7.

Characteristics of blockchain

one of the four characteristics of blockchain: tamper proof

the most easily understood characteristic of blockchain is tamper proof

tamper proof is based on the unique account book of "block + Chain": the blocks with transactions are added to the end of the chain in time order. To modify the data in a block, you need to regenerate all blocks after it
one of the important roles of consensus mechanism is to make it almost impossible to modify a large number of blocks at high cost. Take the blockchain network (such as bitcoin and Ethereum) with workload proof as an example, only with 51% of computing power can all blocks be regenerated to tamper with data. However, the destruction of data is not in line with the self-interest of players with large computing power. This practical design enhances the reliability of data on the blockchain
generally, the transaction data in the blockchain ledger can not be "modified", it can only be "modified" through the new transactions that are approved. The process of correction will leave traces, which is why the blockchain can not be tampered with. Tampering refers to changing or misinterpreting by means of forgery
in today's common files and relational data, unless a special design is adopted, the system itself does not record modification traces. Blockchain ledger adopts a design different from that of files and databases. It draws on the design of ledger in reality, that is, to retain the traces of records. Therefore, we can not "modify" the account book without leaving traces, but can only "modify" the account book (see Figure 2)

Figure 6: bitcoin is centralized in the organization and logically centralized

when we imagine the future organization, the ideal prototype in our mind is often bitcoin organization: completely decentralized autonomous organization. But in practice, for the sake of efficiency and advancement, we will move closer to the centralized organization and finally find a suitable balance point

nowadays, in the blockchain projects that are created and issued through the smart contract of Ethereum and run in a community or ecological way, the ideal state of many projects is similar to the bitcoin organization, but the actual situation is between the completely decentralized organization and the traditional company

when we discuss the fourth feature of blockchain, which is decentralized self-organization, we are actually going out of the code world, involving human organization and collaboration. Now, various discussions and practical explorations have also revealed the significance of blockchain beyond technology: it may serve as an infrastructure to support human proction organization and collaborative change. This is another example of the complete isomorphism between blockchain and Internet. Internet is not only a technology, it has changed people's organization and collaboration

in general, Ethereum has brought blockchain into a new stage. When discussing Ethereum, if we want to summarize two key words, they are smart contract and token; If I can only say one, I will choose "Tong Zheng". I would rather look for its meaning from the history of the Internet and repeat the previous analogy: as a token of value, its role is similar to HTML. With HTML, what kind of website to build depends entirely on our imagination

8. What is blockchain bifurcation? Will bifurcation cause my bitcoin to split in two
it's very easy to upgrade the software in the centralized system. Click "upgrade" in the app store. However, in decentralized systems such as blockchain, "upgrade" is not so simple, and may even result in the bifurcation of blockchain
in short, bifurcation refers to the divergence of opinions ring the "upgrade" of the blockchain, which leads to the bifurcation of the blockchain. Because there is no centralized organization, every code upgrade of digital assets such as bitcoin needs to be approved by the bitcoin community. If the bitcoin community fails to reach an agreement, the blockchain is likely to form a fork
taking bitcoin as an example, in July 2017, in order to solve the congestion problem of bitcoin blockchain, some bitcoin enthusiasts proposed bitcoin cash bifurcation scheme, resulting in bitcoin blockchain split in two
according to whether the forked blockchain is compatible with the old blockchain, the forking can be divided into "hard forking" and "soft forking".