Tezos is an open and distributed blockchain. Blockchains usually have strong constraints that make it so that they have a low TPS (number of Transaction Per Seconds). It is common to define a peripheral system to increase its TPS, by offloading some of its computation and data to this new system. In this frame, the blockchain is called the Layer 1, and the peripheral system the Layer 2.
Major examples of Layer 2 systems include state channels, sidechains and rollups.
Optimistic rollups are a kind of Layer 2 that validate transactions on behalf of the main chain. They are called optimistic, because they work off the assumption that validation is correct until explicitly proven otherwise.
Even though Optimistic rollups don’t lead to faster finality, they increase the throughput (TPS) significantly.
Optimistic rollups have many desirable features:
- Trustless: You don’t have to trust that a majority of the rollup nodes are honest to always be able to withdraw your funds from the rollup. One honest node is enough.
- Permissionless: Anyone can submit operations to a rollup since all the rollup block data is posted on main chain and available.
- Capital efficient: Unlike state channels, rollups do not require that users lock up a bond upfront. Only node providers do.
Integrating a mechanism such as optimistic rollups requires several important changes in the protocol and in the tooling of the ecosystem. Marigold’s work focuses on:
- Building a state of the art Layer 2, bringing to life a rollup processing transactions.
- Upgrading the protocol to support the interaction between Layer 1 and Layer 2.
- Implementing the tooling necessary to interact with a rollup.
In addition, we at Marigold are experimenting to improve optimistic rollups. Namely, interactive refutation proofs and data sharding.