What is sharding for blockchain networks?

Sharding is a technique used to improve the scalability of blockchain networks in various ways.
The purpose of sharding is to potentially increase storage capacity by dividing information into multiple pieces. This can be used to improve performance in general.

When it comes to processing cryptocurrencies, sharding involves splitting the blockchain network into smaller sections; each partition or shard has a unique set of smart contracts and account balances. This allows nodes to be assigned to individual shards to verify transactions and transactions, rather than each node being responsible for every transaction in the entire network. By doing this, sharding can significantly increase the throughput of transactions and solve the scalability problems faced by many existing blockchains.

Sharding brings new challenges to security. It is crucial to ensure that each piece is secure and that the process of verifying and recording transactions remains tamper-proof. Another challenge is the increasing complexity for developers who need to implement a custom communication mechanism for users and applications in different parts. Techniques such as inter-shard communication and certain consensus mechanisms are used to maintain security.

The Ethereum blockchain initially planned to offer a deeper level of sharding by splitting the network into different pieces. However, this idea has largely been relegated to the background. Instead, there was more focus on scaling the network through multiple layers, known as Layer 2 networks, using rollup technology. These layers process large amounts of transactions that are effectively bulk sent to the base layer.

But Layer 2 networks also have their challenges. Apart from the decentralization issue, data availability issues also arise as they deal with a large number of transactions.

Ethereum is now focusing more on using sharding to solve this type of data availability issue to help the network support scaling layers. The main problem is that there is a need to enable bulk aggregation of such large amounts of data to the base layer so that validators can verify the availability of this data.

Ethereum co-founder Vitalik Buterin proposed a solution. The idea is that the Ethereum blockchain has parts to verify the availability of data stored from Layer 2 networks. He suggested that a combination of a randomly selected committee and random sampling would work to verify the availability of such data