Problems faced by blockchain? The problems that blockchain technology can solve are:

The maintenance cost is very high:

Traditional centralized databases only need to be written once, while blockchains need to be written thousands of times; The traditional centralized database only needs to verify the data once, while the blockchain needs to perform thousands of tests on the data; Traditional centralized databases only need to transfer data once to store it, while blockchains need to transfer data thousands of times.

Incentive structures are difficult to design:

How do you ensure that rewards are aligned with network goals? Why does a node retain or update data? When two pieces of data conflict, what makes them choose one piece of data over the other?

These questions are still to be explored and answered, and blockchains need to be consistent not only at the beginning, but also at all future point in time.

All upgrades are spontaneous :

The most important thing about blockchain is that it is not under the control of a single entity, and it is impossible to force upgrades. All upgrades must be backwards compatible. This is obviously quite difficult, especially if you want to add new features, and even more so from a testing perspective.

Each version of the software adds a lot to the test matrix and extends the release time.

Scaling is difficult

Scaling is at least orders of magnitude more difficult than traditional centralized systems. The same data must exist in hundreds or thousands of places, not in a single place. The cost of transfer, validation, and storage is enormous, as the cost of paying each individual node in the database must be replaced by the cost of paying only once in a traditional centralized database.

All of the above has led to the fact that there are no killer applications for blockchain (with the exception of Bitcoin).

Quote from: Why blockchain is not so simple.

There are 2 main problems.

The first blockchain generally establishes a decentralized security maintenance mechanism through an incentive system, but there is a disadvantage that the general incentive system will issue coins, which is not supported in China.

The second is the technical bottleneck, the TPS of the blockchain is generally not high, and it cannot support the landing of a large number of applications.

Blockchain. It mainly solves the trust and security problem of transactions, so it proposes four technological innovations for this problem:

1. Distributed ledger means that transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records a complete account, so they can participate in supervising the legitimacy of the transaction and can also jointly testify for it. Different from the traditional centralized bookkeeping solution, no node can record accounts separately, thus avoiding the possibility of a single bookkeeper being controlled or bribed to keep false accounts. On the other hand, because there are enough accounting nodes, theoretically speaking, unless all nodes are destroyed, the accounts will not be lost, thus ensuring the security of the account data.

2. Symmetric encryption.

and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted and can only be accessed with the authorization of the data owner, thus ensuring the security of the data and the privacy of the individual.

3. The consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms for different application scenarios, striking a balance between efficiency and security. Take Bitcoin.

For example, with proof-of-work, it is only possible to forge a non-existent record if it controls more than 51% of the accounting nodes on the entire network. When there are enough nodes joining the blockchain, this is basically impossible, thus eliminating the possibility of fraud.

4. Smart contracts.

Smart contracts are based on this trusted, immutable data that can automate the execution of pre-defined rules and terms. Taking insurance as an example, if everyone's information (including medical information and risk information) is true and credible, it is easy to automate claims in some standardized insurance products.

Blockchain is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. In a narrow sense, blockchain is a chain data structure that combines data blocks in a chronological order in a sequential manner, and is cryptographically guaranteed to be tamper-proof and unforgeable distributed ledger.

It has just started the promotion stage, and the ** department has already publicly supported the development. Normal should be promising.

Blockchain can be useful, but it's by no means a panacea.

There are two main problems with blockchain.

1 The blockchain cannot verify the authenticity of information outside the system, and if the information uploaded to the blockchain itself is fake, the anti-counterfeiting and anti-tampering of the blockchain is worthless. If you want to ensure the authenticity of the uploaded information, you still need to have an authoritative authority to check it. If they all believe the information uploaded by this authority, why should they be afraid that it will tamper with the information?

What is the difference between using blockchain and not?

2 In the blockchain world, ** is the law, and the system can run automatically, but once it interacts with the real world, the real world may not necessarily agree with the law. For example, if a contract is signed on the blockchain, it will be automatically executed when it expires, and the assets will be transferred, but if there is an old man who does not implement the real asset transfer according to the contract on the blockchain, the contract is a dead letter, and the court and other institutions in reality have to take action.

The reason why the first application of blockchain, Bitcoin, has such an impact is that it can just avoid the above two problems.

Bitcoin is completely self-contained, all information is generated within the Bitcoin system, it is closed and verifiable, Bitcoin is not pegged to any real asset, so it can be easily run automatically through the program.

Because Bitcoin is completely virtual, completely operated by procedures and rules, it has no borders, is not subject to regulatory control, does not need to be exchanged, circulates freely, cannot be frozen and confiscated, is available to everyone, and will not be over-issued and depreciated, which is its advantage over fiat currency.

However, because Bitcoin runs completely autonomously on dead rules and procedures, the supply of Bitcoin is inelastic, and if the private key is stolen, the property will be lost and cannot be recovered, which is also its disadvantage.

Similarly, in reality, using blockchain technology, if the real pursuit of ** is the law, the private key proves everything, if the private key is stolen, it will inevitably lead to the loss of assets and cannot be recovered. For example, if you map shares to the blockchain, is it possible that if a major shareholder's private key is lost, all his shares will not be used? This is also an unavoidable problem for blockchain.

To sum up, the real killer application of blockchain is actually cryptocurrency. Engaging in coinless blockchain does not have such a subversive effect, and it is necessary to beware of some ** cheating money and subsidies under the banner of blockchain.

Digital currency Bitcoin [Super Talk].

1.Performance issues.

Volume issues. Blockchain's requirement for data backup challenges storage space. The blockchain requires that a transaction be broadcast to the whole network after it is reached, and each node in the system must back up the data.

Taking Bitcoin as an example, the block data since the genesis block has exceeded 60GB, and the amount of blockchain data is still increasing, which will bring great challenges to the operation of Bitcoin Core clients.

Dealing with speed issues.

The Bitcoin blockchain currently processes transactions per second at a maximum of about 10 minutes, which is prone to congestion and delay in a large number of transactions, which may limit the application of small multiple transactions and time-sensitive transactions.

Although there are some ways to overcome it, there is still an urgent need to find a comprehensive solution to transaction efficiency.

The energy consumption is too high. Third, the computing power in the mining process does not generate additional actual social value, and will waste a large amount of electronic resources, with the increasing popularity of Bitcoin, blockchain has gradually become a high-energy-intensive capital-intensive industry.

2.The problem of centralization.

inequality of nodes.

First, theoretically, each node in the distributed network should be treated equally, but in order to obtain rewards for mining, each node may increase its computing power to compete in hardware, which will lead to inequality of nodes and destroy the random chaining of blockchain accounting rights.

Industrialization and large-scale mining have produced mining pools.

Theoretically, if the mining pool is to master more than 51% of the computing power for system supply through collusion, double payment can be realized, and although the cost far exceeds the benefit in practice, the possibility of collusive supply cannot be denied.

3.Privacy and security issues.

Private keys are easy to steal.

First, the current blockchain uses an asymmetric key mechanism, which is highly secure, but the private key is stored locally by the user and is easy to be stolen by hackers.

The transparency of blockchain data is prone to privacy leakage.

Every participant in the public chain can get a complete data backup, the whole system is open and transparent, and Bitcoin protects privacy by isolating the connection between the transaction address and the real identity of the holder.

4.Escalation and incentive issues.

The number of participating nodes in the public chain is huge.

Either the upgrade or the bug fixing cannot be shut down and the system is centralized, and the problem of relaxing decentralization may need to be considered.

There is a competitive game between the nodes.

Another challenge faced by blockchains is how to enable self-interested blind nodes in the decentralized system to spontaneously carry out block data verification and bookkeeping, and to design a reasonable penalty function to suppress irrational competition.