How does Based-Rollup reconstruct the L2 power structure?

The article explores how Based-Rollup redefines the L2 power structure by addressing the blockchain trilemma (security, decentralization, scalability) and reducing the centralized power of L2 sequencers. Key points:

L2's Core Problem: Ethereum's low gas fees raise questions about L2's necessity, but L2 solutions aim to balance security (via L1), decentralization (via sequencers), and scalability (off-chain execution).
Based-Rollup's Innovation: Proposed by Vitalik and promoted by Taiko, Based-Rollup shifts sequencing power to Ethereum L1, limiting L2 sequencer dominance and MEV exploitation. It involves:
- L2 searchers packaging transactions for L2 builders.
- L2 builders constructing blocks.
- L1 searchers including L2 blocks in L1 blocks (leveraging L1's redundant resources).
Comparison to Traditional L2s: Unlike OP/ZK Rollups, Based-Rollup avoids sequencer centralization by integrating L1 into the process, akin to a "deputy governor" (L1 searcher) overseeing a "mayor" (L2 builder).
Taiko's BBR (Based Booster Rollup): A newer concept mirroring L1's state, though details are reserved for future discussion.

This approach reallocates power to L1 while maintaining L2 efficiency, offering a novel solution to decentralization challenges.

Judging from the current results, after the gas fee of Ethereum L1 mainnet dropped to the lowest level in 5 years, many projects feel that it is not impossible to deploy on L1. So many people will ask, what core problem is L2 solving now?

There is an old topic called the impossible triangle of blockchain. According to Vitalik, you can only choose two among [security], [decentralization] and [scalability].

Returning to the essence of technology, this is the problem that L2 should solve:

First, the state summary is placed on L1 and maintained by the main network [security];

Second, work hard on the sorter to keep it decentralized;

Finally, [scalability] is implemented as cleverly as possible by L2 off-chain.

Different L2 solutions have their own advantages. Everyone is familiar with OP Rollup and ZK Rollup. Today I want to talk about something different, such as Based-Rollup.

The Based L2 solution was also first proposed by Vitalik, and L2 developers such as Taiko have been promoting the Based Rollup idea.

PS: Note that it is Based, which has nothing to do with Coinbase’s Base, which is also from the OP series.

As we all know, in a standard OP L2 system, the orderer has great power. It can decide whose transaction comes first and whose transaction comes later. Even if you don’t do evil, you can still make a profit through MEV. This is why, for example, Metis proposed to build a decentralized orderer.

Different L2s have different solutions for MEV: for example, Arb advocates fair treatment of MEV (strictly first come, first served), while OP is more encouraging, believing that MEV is a free market behavior, so it imposes taxes on MEV. But no matter what, L2 sorters have a prominent position.

Therefore, Based-Rollup chose to wield the knife against the sorter - its idea is to let ETH L1 do the sorting directly, thereby limiting the power of the L2 sorter.

Quoting a picture from @taikoxyz's document:

As you can see, it is a three-step process:

In the first step, the L2 searcher packages the L2 transaction and sends it to the L2 block Builder;

The second step is that L2 Block Builder builds blocks;

In the third step, L1 searchers include L2 blocks in the blocks they built in L1.

The L1 searcher and L2 builder here can be the same person.

This is another clever "doing two jobs" idea. In fact, the performance of the L1 searcher's equipment is redundant, and there is no pressure to do an extra Taiko L2 block build.

To make an inappropriate analogy, if ETH and L2 are likened to the relationship between a province and a city, then the idea of Based Rollup is: let the mayor (L2 builder) serve as the deputy governor (L1 searcher), which actually mobilizes the resources of L1 to protect the security of L2.

It has been exactly one year since Taiko’s TGE, and Token Unlock will begin soon, so Taiko has also been brewing a new idea over the past year, called Based Booster Rollup/BBR.

Booster Rollup can also be used as a mirror of L1. That idea is also very interesting. However, due to limited space, the analysis of Booster Rollup will be expanded in the next article.