What is blockchain? What is the definition?

Blockchain technology is considered the cornerstone of the metaverse, providing a reliable infrastructure for the metaverse and ensuring the security of users' digital assets and transactions in the virtual world. So, what exactly is blockchain?

I. Definition of Blockchain

As the name suggests, a blockchain is a chain of data blocks.

It first appeared in 1991, when a group of researchers used it to timestamp digital documents, ensuring they could not be tampered with. Blockchain technology acts like a notary public.

However, the technology remained largely unused until 2009, when Satoshi Nakamoto used it to create the digital cryptocurrency Bitcoin.

A blockchain is a distributed ledger that is completely public to everyone. It has an interesting property: once data is recorded in the blockchain, it is difficult to alter.

II. Data Blocks

Each block contains three important components: data, a hash value, and the hash value of the previous block.

The data component depends on the type of blockchain. For example, blocks in the Bitcoin blockchain store transaction information, including the seller, buyer, and the amount of bitcoins traded.

Next, let's talk about hash values. They act like a fingerprint for a block, identifying the block and the data it contains.

Once a block is created, its hash value is uniquely determined. Changing any part of the block's content will significantly change its hash value.

The third element in a block is the hash value of the previous block. This element allows blocks to form a chain and ensures the blockchain's security.

As shown in the figure above, suppose we have a blockchain consisting of three blocks: Block 3 points to Block 2, which in turn points to Block 1. Block 1 is special in that it doesn't point to the previous block because it is the first block in the blockchain, also known as the genesis block.

3. How to Prevent Data Tampering

Suppose you tamper with the data in Block 2. This will change its hash value as well. This will invalidate the reference to Block 3, and thus all subsequent blocks. Therefore, altering one block renders all subsequent blocks invalid.

1. Proof of Work (POW)

Hashing alone is insufficient to prevent users from tampering with blocks. With today's computer speeds, which can calculate tens of thousands of hashes per second, it's possible to tamper with a block and recalculate the hashes for all subsequent blocks.

This would render your block legitimate again. To prevent this, blockchains employ a technology called Proof of Work (POW) to slow down the creation of new blocks.

2. Peer-to-Peer Network Architecture

In addition, blockchains offer another security mechanism: decentralization. Unlike centralized networks, blockchains utilize a decentralized, peer-to-peer network, open to anyone.

When someone joins the network, they obtain a copy of the entire blockchain. This person can then verify whether blocks on the blockchain are legitimate or have been tampered with.

IV. Blockchain Principles

1. Transaction Initiation

A blockchain transaction can be a transfer of digital currency, digital assets, or other forms of data transmission. Whenever someone initiates a transaction, it is broadcast to the entire blockchain network.

2. Transaction Verification

Once a transaction is broadcast, everyone in the blockchain network begins verifying its validity, using methods such as proof-of-work or proof-of-stake to ensure there are no double-spending or other fraudulent activities.

3. Transaction Packaging

Transaction information is packaged into a block of data, or "block." This block is appended to the end of the blockchain, becoming part of the blockchain and synchronizing the latest blockchain data to everyone in the network.

4. Blockchain Consensus

Everyone in the blockchain has their own copy and maintains the integrity of the entire blockchain. Consensus algorithms ensure that everyone has the same blockchain data.

5. Immutability

Once transaction data is written to the blockchain, it is difficult to tamper with or delete. Modifying the data in one block affects the hash values of all subsequent blocks. To do so, you would need to modify all subsequent blocks and control more than 50% of the users in the network. This is essentially impossible.

6. Continuous Expansion

The entire blockchain process repeats the above steps. Every time a new transaction is generated, it is verified, packaged into a block, and then added to the blockchain. The blockchain can be said to be a large ledger.

V. Blockchain and the Metaverse

Blockchain technology is a key infrastructure of the metaverse, providing technical support for asset management, payment settlement, identity authentication, and governance within the metaverse. Blockchain's decentralization, immutability, and security make virtual assets and transactions within the metaverse more trustworthy and secure.

Furthermore, the economic system within the metaverse requires blockchain technology to build and maintain. Through blockchain technology, the metaverse can create and manage economic elements such as virtual currencies and digital assets, enabling economic interaction between the virtual and real worlds.

Blockchain technology provides a decentralized identity authentication and governance model for the metaverse. Users can use blockchain technology to ensure the security and reliability of their identity information, while also making the operation of the metaverse more transparent, fair, and democratic.