A Nakamoto coefficient counts the smallest set of entities whose combined control reaches a stated disruption threshold in a specified subsystem. A meaningful comparison names the threshold, observation window, resource weights, and method for grouping entities. Node counts and pool counts are not interchangeable with independent control.
Key idea. First choose the failure being measured; then count the controlling entities needed to reach it.
Example
Illustrative data only: entity shares 40%, 30%, 20%, and 10% require two entities to exceed 50%. At a threshold above one third, one entity suffices. Neither result is a live blockchain measurement.
Keep in mind
- We publish no coefficient for any chain without reproducible data.
- Examine who chooses block contents before reading pool share as consensus control.
- Grouping keys or operators differently can change the result; unknown affiliations must remain unknown.
- Higher measured dispersion in one subsystem does not establish safety in every subsystem.
Sources
- Cardano glossary: Nakamoto coefficient (external site)
- Research: decentralization at multiple granularities (external site)