What is shared sequencing?
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 5 min
In short
Shared sequencing has several rollups delegate ordering to the same set of sequencers. The aim is to avoid every chain running its own single-operator sequencer and to let transactions spanning chains be ordered together. The shared set itself, however, becomes a new dependency.
Key points
- Several rollups share one set of sequencers
- Avoids every chain running its own single operator
- Lets transactions spanning chains be ordered together
- The shared set becomes a dependency of its own
Definition
An arrangement in which multiple rollups delegate transaction ordering to a common set of sequencers, allowing cross-chain transaction ordering to be decided together.
When every rollup runs its own sole sequencer, each chain adds another point of failure and another opportunity for censorship. Shared sequencing aims at ordering that does not depend on any single operator, by having multiple chains use one distributed set of sequencers.
The second motivation is handling transactions that span chains. Today it is hard to guarantee that a sale on one chain and a purchase on another both execute, leaving the risk that only one leg fills. A common sequencer that orders both sides at once makes this easier to address.
On the other hand, a colluding shared set would be positioned to extract reordering profits across several chains at once. Who is allowed to become a sequencer, and whether each chain can keep operating if the set goes down, are things to verify per design.
Watch out for
- · If the shared set halts, every chain relying on it is affected at once
- · Concentrated ordering power can mean cross-chain reordering that works against you
- · A claim of decentralisation is meaningless without checking participant counts and entry conditions