What exactly is blockchain? How is it applied in the Internet of Things?

When mentioning blockchain, people can’t help but think of virtual currencies such as Bitcoin and Ethereum. However, virtual currency is not the same as blockchain. Industrial Router/Gateway In fact, blockchain is the technical basis of virtual currency.

In addition to being applied to virtual currency, blockchain can also be applied to information fields such as public, financial, Internet of Things, logistics, and copyright protection. At the same time, blockchain technology is also a new innovative technology that the country is vigorously promoting.

Since blockchain is so widely used and has broad prospects, we first need to understand what exactly is blockchain.

The history of blockchain

The core technology of blockchain was proposed as early as 1991. At that time, it was only used to mark electronic documents and record every change to determine whether the file had been tampered with. It was not until 2009 that a Japanese-American named Satoshi Nakamoto ( (whose true identity is questionable) first proposed the application of blockchain (created Bitcoin) in an article about the concept of virtual currency, and blockchain began to attract widespread attention.

What is blockchain?

Blockchain is a new type of data storage structure that has the characteristics of decentralization, non-tampering, full traceability, traceability, collective maintenance, openness and transparency. Blockchain involves knowledge in many fields such as mathematics, encryption algorithms, cryptography, the Internet, and computer programming.

Characteristics of blockchain

>>>Decentralization: The most important feature of blockchain is decentralization. What is centralization? That is, around a fixed center.

Take transfer as an example, then there is a ledger to store everyone’s information. If A transfers 100 yuan to B, A’s deposit data on the ledger will be -100, and B’s data will be +100. This is centralization, and all transactions around this ledger. If a malicious bank employee tampered with the ledger data one day, serious consequences would occur at this time, so centralization poses a huge risk. In order to prevent data from being easily tampered with, we need more ledgers to store transaction information at the same time, so that only more than half of the bills can be modified at the same time to complete the modification goal, which greatly increases the difficulty of data tampering, which is also called distribution. style bill.

Asymmetric information encryption: The blockchain uses a hash algorithm to encrypt. Whether it is a sentence, a book, or larger data, the hash algorithm can convert it into a 256-bit binary string, and it is difficult to reverse it. Extremely, we can only rely on constantly using different information for comparison. Taking a computer that can perform 10,000 comparisons per second as an example, it takes 1020 years to crack.

The blockchain can be understood as composed of blocks and chains, and the blockchain is composed of countless blocks and chains. A block can be understood as a bill for each record transaction, so how to connect them?

Each block stores the encrypted information of the previous block, and also stores the data and encrypted information of this time, so that all blocks are linked.

For example: Taking transfer as an example, A transfers 100 yuan to B. In order to ensure the security of the information, the transaction is encrypted and converted into a string of characters (hash value). The first ledger records this Hash value, this ledger is also called the ancestral block (Genesis block). Next, A transfers 1,000 yuan to B. At this time, the second ledger retains the encrypted string of the first transaction, records the transaction, and encrypts the data in the ledger into a string. By analogy, when the third transaction occurs, the third bill records the last and current encrypted strings, so that each block is linked into a blockchain. In this way, the data will be permanently stored as the length of the chain expands. When we want to tamper with one of the data, its encrypted string will be modified, the encrypted strings before and after the block will not correspond, and the block will be considered unreasonable.

IoT applications of blockchain

As can be seen from the previous introduction, the blockchain has the characteristics of high reliability and data permanence. In today's Internet of Things applications, most of them rely on server and client transmission modes. There are data security issues caused by centralized management of data through servers and server pressure issues caused by the increase in the number of transmissions. In some IoT application scenarios with extremely high security requirements, such as driverless technology, the safety factor of command data will be greatly improved. At the same time, point-to-point transmission can be achieved between each vehicle, improving system operation efficiency. From a broader perspective, the security and openness and transparency of the blockchain can formulate corresponding rules so that nodes can obtain information from other public IoT devices (such as sensor data, etc.), and can truly realize "things". Internet of Things”.