How blockchain solves the scalability problem: everything about sharding

Blockchain networks face one of their biggest challenges – how to process millions of transactions simultaneously? This is where sharding comes in, a technology that splits the network into independent parts (shards), allowing operations to be processed in parallel. But how does it actually work? And what risks does it entail?

Sharding: what does it mean in practice?

Imagine that the entire network is a gigantic store with one cashier. He serves all customers one by one, which takes a lot of time. Sharding is the introduction of several cashiers at the same time, each serving a separate line. This is how this mechanism works in the Blockchain.

Essentially, sharding is a horizontal data distribution borrowed from traditional databases. Instead of each node processing all transactions in the network, they are distributed among different shards. Each shard functions as a miniature database capable of independently processing smart contracts and operations. This approach allows for parallel processing instead of sequential, which radically speeds up the entire process.

Why horizontal distribution?

Blockchain networks choose this method of data distribution for three reasons:

Scalability without limits – Each individual shard can process more operations simultaneously than a single system. This means that the network grows along with the number of participants without losing speed.

True decentralization – When each node must store and process only a portion of the data, ordinary users without powerful computers can join the network. This reduces the hardware requirements and makes the network truly decentralized.

Security and Integrity – Each shard retains complete data of its transactions, thus the integrity of the information remains intact. Each node has an exact copy of its part of the Blockchain.

Game-Changing Advantages

Sharding offers several significant advantages for the blockchain ecosystem:

The increase in speed – Ziliqa, one of the networks that implemented sharding, achieves processing of thousands of transactions per second. Instead of sequential processing, operations are executed simultaneously across different shards, allowing for much more users to be serviced.

Resource Savings – Traditional Blockchains require each node to store the entire historical record of the network. Sharding allows nodes to be responsible only for their part, significantly reducing hardware requirements. This opens up participation in validation to regular users, not just organizations with expensive specialized equipment.

Increased throughput – Unlike traditional networks, where additional nodes can slow down the system due to increased synchronization delays, sharding works differently. New nodes are added to individual shards, increasing the overall capacity of the network without degrading performance.

Where are the risks hidden?

However, sharding is not a panacea. It creates specific security threats:

Vulnerability of individual shards – Capturing the entire Blockchain is difficult, but capturing a single shard is significantly easier. An attacker with limited resources can potentially control an individual shard – this type of attack is called “shard capture”. This means that the computational power required for the attack is much lower than that needed to capture the entire network.

Problems with cross-shard transactions – When an operation touches multiple shards, coordination becomes complicated. With improper handling, “double spending” is possible – when a user can spend the same tokens multiple times if different shards inaccurately track one another.

Data Availability – If a shard with important information is temporarily unavailable due to offline nodes, it may block operations in the network.

Node Synchronization – Coordination between shards requires a reliable protocol. Improper implementation leads to resource imbalance, delays, and potential instability of the entire system.

Ethereum and the Future of Sharding

Ethereum recognized the potential of this technology and planned to implement sharding as a key component of the Ethereum 2.0 (Serenity) upgrade. This upgrade aims to significantly improve the speed, efficiency, and scalability of the network.

Developers are implementing this gradually. The full implementation of sharding is scheduled for the final phase of the update (Phase 2). The goal is to address network congestion and high fees that have so far limited the scalability of Ethereum. However, developers are carefully testing each step to ensure that the security mechanism and decentralization remain unchanged.

Sharding as a solution to the blockchain trilemma

Sharding is seen as a significant step towards overcoming the so-called “blockchain trilemma” – the balance between scalability, security, and decentralization. Current solutions often sacrifice one for the sake of another. Sharding offers an approach that allows for scaling the network without giving up decentralization.

Although this technology creates new challenges – from the protection of individual shards to the management of cross-shard operations – its potential outweighs the risks. Various blockchain projects are actively exploring and implementing sharding, aiming to make networks faster and more accessible to millions of users without increasing hardware requirements.

The future of blockchain scalability depends on the continued research, testing, and improvement of sharding implementations. As this technology evolves, it may become a key to the mass adoption of decentralized systems.