Blockchain enthusiasts have a lot of terms and slang. The one you don’t come across often is the ‘Longest Chain’.
Sounds like some technical jargon? It’s not. At least, not so much.
The Longest Chain is a blockchain concept that you will come to understand in this article. And if you read till the end, you’d probably also appreciate this concept.
What is the Longest Chain?
The longest chain is the chain with the most blocks. It is one with the most history of the network. This phenomenon exists in a blockchain system.
Some networks have never encountered a hard fork or split. In such a setting, the original chain is the longest. Some other networks have had a hard fork or split. This tends to duplicate the existing chain.
Only one of these two chains can be utilised. As a result, the chain chosen to continue the network becomes the longest.
This might be a little confusing but don’t worry. The next section details how the longest chains come about in a blockchain network.
How Is the Longest Chain Formed?
A blockchain is made of records bundled up into blocks. These blocks are appended to each other using consensus mechanisms. A new block is typically attached to the last block.
Attaching one to another creates a ‘chain’. However, this can be broken when a consensus failure occurs.
In fact, disagreements about consensus cause the chain to split. Two identical chains emerge from this process. One is a new chain and the other is old.
Different blockchain participants can decide to accept any of these two chains.
Once a decision is made, the selected chain is adopted. Consensus begins on this chain with blocks added as usual.
The continuation of this chain makes it longer than the other copy. Automatically, this becomes the longest chain.
Significance of the Longest Chain in a Blockchain Network
You might be wondering about the longest chain. What significance does it have? Why is it even a thing?
This section will answer precisely that.
Knowing an Honest Chain:
Remember when we spoke about a hard fork? Well, several things could cause it. The major one is a consensus bug.
Bugs may be introduced by unscrupulous elements; attackers for example.
They come in several forms and produce unimaginable outcomes. In the Integer Overflow incident, the bug created a block with 184 million Btcs. The Bitcoin chain was split as a result.
The original copy of the blockchain had the corrupt block in it. The new copy, however, was free of that. Nodes, therefore, agreed to adopt the new chain. They initiated the consensus on this chain and began adding blocks to it.
This way, the new blockchain quickly grew in length.
New users on the Bitcoin blockchain could recognize the most honest chain by looking at length.
Continuous Record Over Time:
Let’s assume a blockchain experienced a hard fork. One chain has 10,000 blocks. The other existing chain has moved to 50,000 blocks.
Which of these two chains is the most up-to-date?
It’s the latter. Having 50,000 blocks is proof of this. It means the chain has been active beyond when the split occurred.
As a result, the longest chain contains a continuous record over time.
Blockchain Openness or Reference:
One of the first things you’ll learn about blockchain is transparency. The system is practically designed to express that. It is so much so that the term ‘trustless’ has been associated with it.
This discloses that trust is not required in blockchain dealings.
Many features maintain trustlessness within decentralised settings. The longest chain is one of them.
Picture it this way. First, a chain is made of blocks containing transaction records. Second, every user has the right to view the transaction records. Third, the longest chain holds the largest amount of records.
Technically, this means the longest chain holds the most history about the network. Since users have the right to access records, this longest chain automatically serves as the best reference. It is the go-to place for complete openness on a network.
The Current Record for the Longest Chain
You may ask what blockchain currently holds the longest chain. But there are two sides to this question. One is on the longest chain after a hard fork. The other is on the longest chain without a hard fork.
The Longest Chain on a Blockchain without a Hard Fork History
Bitcoin blockchain holds the record in this category. From findings, the blockchain has not had any hard fork. There is no such incident in its history.
What this means, astonishingly, is that the Bitcoin chain is complete. It contains records of transactions since the network was launched.
The Longest Chain on a Blockchain with a Hard Fork History
Ethereum appears to hold the record in this category. From findings, the Ethereum blockchain has had several hard forks. Nevertheless, the network usage is significant and equally consistent.
This is what makes the blockchain attain a long chain despite its shortcomings.
Conclusion
There are hard forks, soft forks, and splits. These three concepts all affect the length of a blockchain chain.
And if you’re looking for the main chain in a network, it would usually be the longest. Keeping this handy could help save you from on-chain attacks and frauds.
