2023 Summary for Validiums and Optimiums

While rollups have generally dominated the scaling landscape for Ethereum, it is, however, constrained by the cost of posting transaction data. As a result, L2s that utilize off-chain data availability (DA) are becoming increasingly common. In general, L2s leveraging off-chain data availability that rely on fraud proofs are known as Optimiums, while those that rely on validity proofs are called Validiums. While there is some degree of trade-off in security when opting for off-chain data availability, the cost savings of hosting transaction data off-chain can be rather significant. However, there is evidence that suggests the security trade-offs made by the use of off-chain DAs to lower costs are not a risk many users are willing to take.