Evolution of Modular approach: Build App-specific rollups ecosystem The Rise of Layer2 and the Advent of App-specific Rollups The market for Layer2 solutions utilizing Ethereum's rollup approach has been experiencing rapid growth recently. As of February 2024, there are approximately 80 Layer2 networks, and the total value locked (TVL) has grown 100% in just six months, reaching $27.15 billion. There are even Layer2 networks that have surpassed Ethereum in the number of transactions over a 30-day period, quickly becoming the choice of users. These Layer2 networks are accelerating the development of ecosystems for App-specific rollups, which can maximize the scalability provided by rollups while ensuring lower transaction fees and sovereignty for the Dapps deployed on their networks or using their tech stack. (The adoption of App-specific rollups is being actively discussed, especially in the gaming sector.) image There are three main reasons why rollups, as opposed to smart contracts, are becoming more prevalent in Dapp development. First, unlike smart contracts which are limited by the characteristics of the underlying network, Rollups guarantee scalability, flexibility, and sovereignty to Dapp projects. They inherit security from Ethereum while allowing for various attempts to improve scalability and usability without restrictions. Notably, they can offer an enhanced user experience through fast pre-confirmations compared to Ethereum's 12-second confirmation time. Second, Rollup frameworks like OP Stack, Polygon CDK, Zk Stack, and Madara have become open-source and technically stable. They have been standardized across Layer2, making it easier for anyone to build rollups. Third, Rollup as a Service (RaaS) providers are becoming more active. Providers like Altlayer and Caldera are facilitating the construction of rollups with one-click and no-code deployment options using various rollup frameworks. This maturity in the development environment is accelerating the market for App-specific rollups based on rollups. image

Decentralizing Rollup Sequencers: Towards A Rollup-Centric Ethereum Centralized Sequencers and Their Challenges Rollups have emerged as an off-chain solution to enhance Ethereum's scalability. They operate through entities known as sequencers, which collect transactions from users, create and execute blocks, and then have the results verified on Ethereum Layer 1. Depending on the verification method used on Ethereum, rollups are classified into two types: Optimistic and Validity (or ZK) Rollups. Optimistic Rollups: User transactions are submitted to Ethereum as proof, along with the execution results. A third party can verify and challenge these results through Ethereum. Validity Rollups: These leverage cryptographic zero-knowledge proofs to demonstrate correct execution without requiring a third party. The proof is then verified on Ethereum along with the results. Both methods ensure that the sequencer has correctly processed the transactions, with their security essentially being inherited from Ethereum. This means a sequencer cannot arbitrarily manipulate results. This is why many Layer 2s still use centralized sequencers, which, from a scalability perspective, is not problematic. However, recent discussions focus on the decentralization of rollup sequencers, not only to enhance security but also to foster transparency in order to attract a broader user base. Several key issues arise from the centralization of sequencers: liveness, censorship, MEV, and governance.