An L1, or Layer 1 blockchain, refers to the base layer of a blockchain ecosystem. Blockchain architectures often have layers for scalability, and the layer that can operate by itself with no additional plugins is known as the L1.
This is often also known as the “settlement layer” because it’s the layer of a blockchain ecosystem to which all plugins, layers, or additional components eventually write back.
In this article, we will learn:
and the current L1 Blockchain scalability solutions landscape.
As explained in our guide on blockchain architectures, there are two types of layers we can refer to in the context of blockchains, both commonly referred to as “blockchain layers”:
We're referring to the second type when discussing an L1 or Layer 1 Blockchain. Specifically, we’re referring to the base layer of a blockchain ecosystem, which can operate by itself with no additional plugins. Contrary to a layer 2 blockchain, that requires a layer-1 to function.
As our guide on blockchain architectures discusses, the blockchain trilemma is one key issue all layer 1 blockchain need to solve.
The term "blockchain trilemma" was first introduced by Vitalik Buterin to describe the three properties of a high-performing blockchain:
The trilemma states that a blockchain can only excel in two of these three areas at once.
To address this, some developers have taken blockchains like Ethereum or Bitcoin, and instead of trying to create a single chain that is both scalable, secure, and decentralized, they have opted to create two chains:
In addition, L1 chains are often mission-driven, and anything that perverts the mission is generally not included in the development of the L1. This is often because it would hinder other parts of the blockchain scalability trilemma.
For example, the Ethereum network did not put the ability to directly read the price of assets from the real world (the device that reads asset prices from the real world is also known as an “oracle”) because the vision of Ethereum is a completely unbiased global computer. Reading asset prices made it difficult for it to retain its unbiased mission, so when Chainlink launched on top of Ethereum, we’d refer to Chainlink as an L2 or “Layer 2”.
Having multiple layers of a blockchain allows each to retain certain security and decentralization implications without sacrificing the entire system.
With all these challenges, there is plenty of room for different L1 solutions that address scalability problems in various ways. These are some of the most popular ones.
As we’ve seen, scaling Layer 1 chains confronts a fundamental hurdle. The scalability trilemma highlights this predicament, emphasizing the challenge of expanding transaction capacity without compromising security or decentralization.
To solve the challenges related to the scalability trilemma, Layer 1 blockchains can implement one of the following scalability solutions to improve some of the aspect of the trilemma, without relying on a Layer-2 blockchain:
Sharding is a solution to break the network’s data into smaller, more manageable shards. Image a large, bustling marketplace that’s become too crowded. To manage the crowd better, the marketplace is divided into smaller sections, each specializing in different goods. This way, shoppers can find what they need more quickly and efficiently because each section is less crowded and easier to navigate.
In blockchain, sharding does something similar. Instead of having every single transaction processed by every node in the network, sharding divides the network’s data into shards. Each shard contains a portion of the network’s transaction history, smart contracts, and account balances. The Ethereum blockchain for example, is implementing a variation of Sharding - Danksharding, now partially live thanks to the recent Proto-danksharding eip-4844 release.
Sharding allows the parallel processing of transactions, significantly speeding up the validation process since each node only processes the transactions for its respective shard.
Changing a consensus mechanism is like altering the rules of a game for how players (in this case, nodes) agree on the state of the blockchain ledger. Bitcoin’s Nakamoto consensus based on Proof-of-work (PoW) and Ethereum’s Gasper consensus based on Proof-of-Stake (PoS) are two types of consensus. Ethereum was initially proof-of-work-based but migrated to PoS-based to help with transaction throughput. This is a great example of how this can help with the scalability issue, as they could go from a TPS of 10 to around 32 Blocks per second.
This implies that the consensus layer of the internal chain infrastructure must be changed, and sometimes, doing this at this level is not optimal, as we will see later in the article, that some Layer 2 addresses this problem.
Forking a blockchain is similar to taking a road that splits into two directions. This can happen for several reasons, such as adding new features, correcting security flaws, or resolving disagreements within the community about the blockchain’s future direction.
There are two primary forks:
As we've learned in this article on what layer 1 blockchains are - An L1, refers to the base layer of a blockchain ecosystem. A blockchain ecosystem can in fact have several layers. The Ethereum L1 has several L2s like zkSync, Arbitrum, and Optimism. Bitcoin has a layer two in the lightning network, aiming to scale Bitcoin's transaction throughput. The Solana network, on the other hand, has very few to no L2s because of how large the base layer (L1) is.
The layer that can operate by itself with no additional plugins is known as an L1 Blockchain.
