Rollups Solutions

What Are Blockchain Rollups?

Blockchain rollups are Layer2 solutions that aim to increase the throughput of a blockchain by processing transactions off-chain and then posting the result to the main chain. They are called “rollups” because they “roll up” many transactions into a single one, reducing the amount of data that needs to be stored on-chain.

What Is an Optimistic Rollup?

Optimistic Rollups are a type of rollup where the state is assumed to be correct unless proven otherwise. In other words, transactions are processed off-chain and the results are posted on-chain. However, these results are not immediately finalized. Instead, they are subject to a “challenge period”, during which any observer can prove them wrong.

How do optimistic rollups validate transactions?

In Optimistic Rollups, transactions are validated by the users themselves. If a user sees an incorrect transaction, they can submit a “fraud proof” to the network. If the fraud proof is accepted, the incorrect transaction is rolled back and the party who submitted the incorrect transaction is penalized.

Limitations of optimistic rollups

While Optimistic Rollups offer increased scalability, they also have some limitations. For one, the challenge period introduces a delay in transaction finality. Additionally, the system relies on users to monitor and challenge incorrect transactions, which requires active participation and can be a complex process.

What Is a zk-Rollup?

zk-Rollups are another type of rollup that use zero-knowledge proofs to validate transactions. Unlike Optimistic Rollups, zk-Rollups provide immediate transaction finality. This is because the zero-knowledge proof that is posted on-chain provides a mathematical guarantee that the off-chain transactions are correct.

How do zk-rollups validate transactions?

In zk-Rollups, transactions are validated using zero-knowledge proofs. These are cryptographic proofs that allow one party to prove to another that they know a value, without revealing any information about the value itself. In the context of zk-Rollups, they are used to prove that the off-chain transactions are valid, without revealing any details about the transactions themselves.

Benefits of zk-rollups

zk-Rollups offer several benefits. They provide immediate transaction finality, which can be important for certain use cases. They also reduce the amount of data that needs to be stored on-chain, which can lead to lower transaction fees for validators. Furthermore, because they don’t rely on a challenge period, they don’t require users to actively monitor and challenge transactions.

Differences Between zk-Rollups and Optimistic Rollups

While both zk-Rollups and Optimistic Rollups aim to increase blockchain scalability, they do so in different ways and offer different trade-offs. The main difference lies in how they validate transactions. Optimistic Rollups rely on a challenge period and require active participation from users, while zk-Rollups use cryptographic proofs to provide immediate transaction finality. This can make zk-Rollups more suitable for use cases that require quick transaction finality, while Optimistic Rollups might be more suitable for use cases where users are willing and able to actively participate in validating transactions.