Rollups: Efficient Scaling for Ethereum Layer 1 or the Dilution of its Security

Abstract

The Ethereum Trilemma states that security, scalability, and decentralization cannot all be achieved at the same time in a blockchain. We call this the ‘Ethereum’ Trilemma because there are solutions to generic blockchain scalability. Due to the added computation, Ethereum has certain challenges that so far cannot be solved without going to Layer 2 or completely changing the base chain. Layer 2 scaling techniques are add-ons to Layer 1 (the base chain). These scaling techniques, may, in some cases reduce the security of the blockchain - but it depends on the definition of security one uses. We examine the implications of Layer 2 scaling (particularly optimistic rollups since they are most popular) and note that decentralized computation and smart contract security have been relegated to a back seat at best or tossed out completely at worst - validation appears to be left behind. This is a gap in rollups that neither Optimistic Rollups nor ZK-Rollups fill. We propose to fill that gap with what we call an $\mathrm{n} \%$-Validations Rollup that bring some validation back - not fully decentralized, but not completely centralized either; the best of both worlds. In our vision, the user needs more options to specify their desired level of decentralized validation. Currently, if you use a rollup, you have potentially no Layer 1 validation. On the other extreme, too much validation is the scaling roadblock. This position paper suggests avenues for research of these issues. This is a transitional period for Ethereum and Layer 2 appears to have become the wild west.