Validity Proof vs Fraud Proof
Dear Anon, *Not Financial Advice*
After just finishing the Delphi Clubhouse of the top L2 teams (Arbitrum,Stark,Optimism,Zk Sync) I have some rough notes that may help to summarize the conversations and also some of my own personal opinions so this is not financial advice.
Not to break anyone's spirit here but I think that as the supply of L2 Scaling solutions is released it will be met with insane demands and we may end up right back where we started. As these solutions come out they will be used up more as the fees are lower and more scaling efforts. With this in mind I don't think we can solely rely on L2 Solutions to solve the ETH scalability problem but it will increase the base limit of users that are willing to pay the higher ETH gas fees.
What is a Roll Up?
The first thing we must understand here is that the purpose of these Roll-ups is to extend the usage of Ethereum and that all these teams are an extension of the ETH community. A Rollup is an off-chain aggregation of transactions inside an Ethereum smart contract so this will reduce the fees and congestion but keep the security of Ethereum L1. We are grouping transactions and computing some parts of the transaction off chain and then finalizing these transactions on the ETH Layer 1. Now lets move on to the popular types of Roll Ups as the purpose of this piece is not to describe the mechanics too in depth but give a brief overview of the scaling process and current debates. Please use google and google the following headlines if you wish to pursue more information or other sources with a different bias.
Validity Roll Up
(Stark,ZK Sync) ZK reduces computing and storage resources for validating the block by reducing the amount of data held in a transaction; zero knowledge of the entire data is needed. ZK-Rollups bundle hundreds of transfers into a single transaction. The smart contract will deconstruct and verify all of the transfers held in a single transaction.
Fraud Proof
(Arbitrum,Optimism) Anybody can participate in verifying the chain & submitting a dispute if they notice fraudulent activity. Fraud Proofs are not executed until they are finalized by the ETH chain. Since they may be invalid at certain times Fraud proofs are collateralized by a bot, execution of fraud proof is slightly more expensive, because of this you must make sure the bond is always greater than the gas fee for the person that has to execute the gas cost, if not worth the time then concern around fraud proofs being censored, miners will want to send the fraud proofs themselves (Unsure the probability of such an “attack”)
Anon Thoughts:
As for Fraud Proof Roll Ups they could have a place in specific situations. but ,I am rather Bullish on ZK Sync 2.0 EVM compatible roll up.
EVM Compatiable,Testnet and Mainnet coming this year to support trading and NFTS on ZkSync ,Higher Throughput tx, Same security as ETH, no withdrawal wait time, Less information needed in each batch. Anon is very bullish on ZKSync 2.0. fraud proofs for large blocks can require more gas than permitted by the L1 block gas limit. These fraud proofs must then be broken down into multiple ETH transactions. Fraud Proofs may have more scaling barriers than ZK although Fraud proofs may be quicker to market ZK solutions may be more scalable over time since they allow for a higher throughput.
As these may allow more users into the ETH network I think gas fees will return to high prices because of simple supply and demand for use of the ETH network. May be a case for different purpose specific blockchains that interact with each other and the main chain as another possible scaling solution using an Internet of blockchains style concept but the near term solutions seem to be L2 roll ups to take some of the transactions off the main chain.
