Ethereum is one of the most popular blockchains but everybody knows about their scaling issues. Ethereum users suffer from high gas fees due to congestion. This article will go over Rollups as scaling solution.

Rollups

There are a lot of layer 2 solutions for Ethereum. Some are fully secure by Ethereum security but only work well for a specific set of applications. Other layer 2 solutions like sidechains are usually EVM compatible but they do not rely on Ethereum for security since they have their own consensus model.

Rollups try to bring the best of both worlds together. This is done by creating a general-purpose solution while still having the security of Ethereum.

Transactions get settled outside of the main network but then the transaction data gets posted back to the Ethereum network.

Each Rollup has its own specific smart contracts deployed on the Ethereum blockchain. By using a Rollup you reduce the load on the main Ethereum network of processing those transactions. This results in lower fees.

Types of Rollups

Optimistic Rollups

Optimistic Rollups assume that the transaction data submitted to the Ethereum network is correct and valid. If it turns out that the transaction data is invalid, there is a dispute resolution. This is done by offering a fraud proof against that transaction.

Both parties, the one submitting the transaction data and the one submitting the fraud proof, have their ETH staked. If there is any misconduct from either party this results in loss of their ETH.

Examples for optimistic rollups:

  • Optimism
  • Arbitrum

Zero-Knowledge Rollups

Zero-Knowledge Rollups or ZK-Rollups do not have any dispute resolution mechanism. In this model, every batch of transactions that get submitted to Ethereum includes a cryptographic proof called SNARK which is verified by a contract. This contract holds data on all transfers on the rollups chain and can only be updated with validity proof.

Thanks to this model ZK-Rollups are quicker and cheaper than Optimism Rollups.

Examples for zk-rollups:

How do you buy ETH?

One of the easiest ways of buying ETH is by using exchanges like Kucoin, Coinbase or Binance.

If you do not want to use a centralized exchange you can use a decentralized exchange. You can also buy ETH directly in your MetaMask Wallet.