The blockchain has the following problems:
The problem of excessive blockchain capacity.
With the development of blockchain, the amount of blockchain data stored by nodes will become larger and larger, and the burden of storage and calculation will become heavier and heavier.
Take the bitcoin blockchain as an example, and its complete data has reached about 7 1GB at present. If users use the Bitcoin core client to synchronize data, they may not be able to synchronize for three days and three nights, and the amount of data in the blockchain is still increasing, which brings a great threshold to the operation of the Bitcoin core client.
Confirmation time of blockchain data.
The current blockchain system, especially the financial blockchain system, has the problem of long data confirmation time.
Take the bitcoin blockchain as an example. At present, the confirmation time of bitcoin transactions is about 10 minute. In the case of six confirmations, it takes about 1 hour. Of course, for the 2-3 days credit card confirmation time, Bitcoin has made great progress, but it is still far from the ideal state.
Deal with the issue of transaction frequency.
The blockchain system faces the problem of low transaction frequency.
Take the bitcoin blockchain as an example. The average size of each transaction is about 250 bytes. If the block size is limited to 1MB, then the number of transactions that can be saved is 4000.
According to the speed of generating a block every 10 minute, 144 blocks can be generated every day, which can accommodate 576,000 transactions. Divided by 86,400 seconds per day, the Bitcoin blockchain can handle 6.67 transactions per second.
At present, the actual daily trading volume of the bitcoin blockchain is close to the system bottleneck (pictured). If the expansion problem is not solved, it may cause a lot of transaction congestion delay.
Compared with Paypal 20 13' s 729 million transactions in the third quarter, the average number of transactions of Bitcoin block (source: block dollars) is 93.75 transactions per second.
According to the official website of VISA, the world's largest payment card, VisaNet handled 47,000 transactions per second in the 20 13 test.
Compared with major payment networks such as Alipay, the bitcoin blockchain is more like a newborn in transaction processing frequency.
Of course, it was also carefully designed by Satoshi Nakamoto in his early days. Bitcoin block size is limited to 1MB to avoid malicious behavior of rogue miners and have a negative impact on people. The reason why the bitcoin blockchain payment network can develop to the scale of billions of dollars today is because of its decentralization.
The development of blockchain is limited by the existing system.
On the one hand, the characteristics of decentralization and autonomy of blockchain dilute the concept of state supervision and have an impact on the current system.
For example, digital currency, represented by Bitcoin, not only challenges the right to issue national currency, but also affects the transmission effect of monetary policy, weakens the ability of the central bank to regulate the economy, and makes the monetary authorities cautious about the development of digital currency.
On the other hand, the regulatory authorities also lack full understanding and expectation of the new technology of blockchain, and the establishment of legal system may lag behind, resulting in the lack of necessary institutional norms and legal protection for economic activities using blockchain. In fact, it increases the risk of market participants.
The cost of integrating blockchain technology with existing systems is relatively high.