Layer 1 is often thought to be the basic layer of blockchain technology. But that is not true, because we also have layer 0. The basis of the blockchain is layer 0 and consists of a set of components with which a decentralized network can function. Therefore, the layer 0 is at the beginning of the interoperability and scalability of blockchains. However, we don’t often hear about layer 0, even though it has been around since the dawn of the blockchain technology.
As blockchains have become more widely used in recent years, we saw that many popular layer 1 blockchains suffered from the scalability problem. Just think of Bitcoin, but especially Ethereum. The rise of DeFi fueled an increase in the use of Ethereum. More and more developers wanted to build an application on Ethereum. And more and more users made use of these dApps. The network became overloaded and could no longer handle the large number of transactions. These issues brought layer 0 back into the spotlight.
Blockchain layers #
Before we dive deeper into what layer 0 is, let’s first explain blockchain layers. It is important to understand how these layers work before we can explain what layer 0 is.
Layer 1 #
Blockchains and protocols can be divided into different layers. The layer 1 is a layer of a blockchain that does not depend on any other blockchain to function. Ethereum, Bitcoin, Litecoin, Ripple and Solana are ideal examples of layer 1 blockchains. These networks work with their own network and are not dependent on others.
On layer 1 blockchains, other developers can build an application. This makes these types of developers dependent on a blockchain. Therefore, all applications that run on the blockchain do not belong to the layer 1 category.
Layer 2 #
Developers have long been trying to solve the scalability problem. They can build a layer 2 scaling solution for that. This is a protocol that runs on top of an existing blockchain and ensures that more transactions can be processed. The result is that a transaction can be validated cheaper and faster.
Polygon is a well-known layer 2 scaling solution that runs on the Ethereum blockchain. This solution ensures that transactions are processed quickly on the Polygon sidechain, after which the answer of the transaction is stored on the Ethereum blockchain. Polygon cannot therefore work independently of Ethereum and is completely dependent on this layer 1 blockchain.
More layers #
In addition to layer 1 and layer 2, there are several blockchain layers. Consider, for example, layer 3 and layer 4. Each layer, which is built on top of each other in a pyramid shape, performs a different function within the network of blockchain technology.
A layer always depends on the layer below itself. This means that layer 2 is dependent on layer 1, and that layer 3 is dependent on layer 2 (and therefore also on layer 1). This only works in this direction. A layer is therefore not dependent on the layer above itself.
Layer 1 blockchains sometimes seem dependent on layer 2 applications, as these improve scalability. But that is not true. A layer 1 blockchain can function well without layer 2 applications, only transactions can only be processed less quickly and less cheaply.
What is blockchain layer 0? #
Layer 0 is the common foundation for all blockchains and contains several components to ensure operation and decentralization. These components include servers, users, nodes and the Internet. The difference between layer 1 blockchains is that a layer 1 blockchain contains mainly and only nodes and users as components.
Some say that every blockchain has a layer 0. According to them, the consensus mechanism is layer 0, and all transactions and applications take place on layer 1. However, that is not quite what we mean here. In this case, it mainly concerns advanced layer 0 protocols that guarantee interoperability.
Interoperability of blockchains #
By interoperability we mean the cooperation between different systems. In this case, it concerns the cooperation between different blockchains, but also between blockchains and other central systems, such as web servers. Because these systems normally work in a different way from each other, it is often not possible for these systems to work together.
For example, you cannot send Bitcoins over the Ethereum network. Both blockchains use different protocols and standards. It is also not possible to simply store data on a central Google web server via the Ethereum network.
We see that more and more blockchain bridges are being created that can make connections between different systems. Make no mistake, these kinds of protocols that improve interoperability do not fall under layer 0. They are in fact layer 2 and layer 3 solutions. They run on top of the layer 1 blockchain. These types of bridges are therefore dependent on the layer 1 blockchain, while the layer 1 blockchain does not depend on these bridges.
Layer 0 as a communication system #
You could see layer 0 as a communication system. It is a communication system that allows all protocols to communicate with each other, provided they have the same layer 0 solution as a basis.
Difficult to understand? Perhaps the example below will make it clearer.
Think of a village. This village is the blockchain world. Every house in the village is not connected to the internet, making it impossible to communicate between the houses. You could think of these houses as layer 1 blockchains. They all work separately from each other and need no one but themselves. However, the houses cannot communicate with each other, because there is no connection that makes that possible.
Inside the houses are rooms. These rooms are separated from each other by walls and doors. It is possible that all the rooms within the house communicate with each other, as the doors connect the rooms. You can see this as layer 2 applications. These are located within the layer 1 blockchain and cannot communicate with protocols and applications outside the layer 1 blockchain.
Now it is decided to lay cables in the ground to connect the houses. The ground can be seen as layer 0. It provides the connection between several houses, or the layer 1 blockchains.
Layer 0 not only allows layer 1 blockchains to communicate with each other. Because all rooms within the house can now communicate with the rooms in the other houses via the layer 1 blockchain, and then via layer 0. This means that layer 2 apps from blockchain A can communicate with layer 2 apps from blockchain B.
The layer 0 is therefore very important. When this disappears, communication between the different blockchains and all applications belonging to them would stop.
Software Development Kit (SKD) #
Layer 0 is not the basis of the interoperability between blockchains. They can also make it easier for developers to set up a new blockchain environment through Software Development Kits (SDKs). You could think of this as a development kit that provides the foundation for a new environment.
If a developer wants to set up their own blockchain, the developer has to spend a lot of time, effort and money on the development of the blockchain. This ensures that less time can be spent on the functionality of the project.
Within a layer 0 environment, developers can use the SDK to set up their own blockchain environment. The SDK already contains a foundation for the environment. This makes it much easier for the developer to set up such an environment themselves. Result? The developer has more time for the development of the functionality, and less time is spent on the foundation of the blockchain. Think, for example, of the mainchain, the consensus mechanism, the nodes, etc.
Conclusión #
Blockchain technology consists of several layers. We usually talk about layer 1 and layer 2, while there is another layer that is perhaps much more important: layer 0. A layer 0 blockchain takes care of the communication between blockchains. It improves interoperability and ensures that developers can easily, quickly and easily set up new blockchain environments. The advantage is that this allows them to focus much better on the functionality of their application.
