Sharding

Quick definition

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Updated: Jan 20, 2023

Sharding involves splitting a network into multiple instances to allow more transactions per second.

Key details

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  • Sharding entails splitting a blockchain network into “shards.” It’s possible for each shard to contain its own version of a blockchain.
  • The Ethereum network will use sharding as a technique to improve its scalability with ‘ETH2’, the updated version of its blockchain.
  • Blockchains that use sharding are prone to security risks such as “shard takeovers”, which a single part of the network can be isolated and attacked.

What is sharding?

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Sharding involves splitting a blockchain network apart to allow data to be processed quicker. When too many transactions take place on a blockchain, it’s not unusual for the blockchain to slow down and transactions to run into errors. To increase the number of transactions per second and data that can run through a network, blockchains must be able to scale. To help blockchain scalability, developers may turn to a data partitioning method known as ‘sharding’.

A blockchain is made up of nodes that validate transactions. Normally, these nodes would need to process the whole network’s data for transactions to be validated. With sharding, these nodes only contain information that’s needed for their part of the network instead of the whole network, this way, transactions can be processed quicker.

Which blockchains use sharding?

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The Polkadot network currently utilises sharding techniques to manage its data and transactions. On Polkadot, each network is called a parachain and each parachain is its own blockchain processing its own data. These parachains are all connected to a relay chain which manages the way all the parachains communicate with each other so that they can all keep up to date simultaneously.

The Avalanche blockchain is similar to Polkadots. Avalanche involves a relay chain that is connected to a platform chain which enables the network to shard and increase scalability, an exchange chain responsible for exchanging assets on the network, and a contract chain for creating smart contracts.

The Ethereum sharding method will involve a beacon chain that performs like Polkadot’s relay chain, and 64 shards whereby nodes are assigned to one of the 64 shards at random where they will be responsible for processing their own share of the Ethereum network simultaneously with other nodes.

What are the risks of sharding?

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A shard takeover is when malicious nodes corrupt a shard, or multiple shards, thus distorting a part of the network and forcing the network out of sync or shutting a part of the network down.

One of Ethereum’s techniques to avoid shard takeovers will be to randomly assign nodes to an arbitrary shard on the network at random periods. This will be done in hopes that potential assailants will struggle to know when the best time to attack a node will be and which node they will be potentially attacking.

Where can I learn more?

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To learn more about how the blockchain works, visit our learning hub. If you’d like to learn more about cryptocurrencies and how to invest in them then head over to the investing hub.



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James Knight
Editor of Education
James is the Editor of Education for Invezz, where he covers topics from across the financial world, from the stock market, to cryptocurrency, to macroeconomic markets.... read more.