What is the Nakamoto coefficient?
The fewest representatives that could together disrupt the Nano network. What the stall and control figures mean, and how hosting affects them.
The Nakamoto coefficient is the smallest number of participants who could together disrupt a network. Higher is better.
Where the idea comes from
It turns decentralization into a number: count the largest participants in order of size until they add up to enough to break something. On a proof-of-work chain that means mining pools. On Nano it means voting weight, since weight decides whether the network agrees.
The two thresholds
Nano confirms a block on at least 67% of online voting weight. That leaves two ways to interfere, so there are two coefficients.
- Stall (33%) is the fewest reps holding more than a third of online weight. If they stop voting, the rest cannot reach 67% and confirmations stop. An outage is enough.
- Control (67%) is the fewest reps that reach quorum alone. They could confirm blocks without the rest of the network.
Control is never the smaller of the two. A network can be halted before it can be taken over.
A stall works because the bar does not drop with the reps that stop. Quorum uses the highest of online weight, trended weight and a fixed minimum, so it stays put while the online total falls.
Both figures count against online weight. When trended weight is higher, the real bar is too, so control is a floor rather than an exact count.
How it is calculated
Every online rep and its weight is snapshotted hourly, and both coefficients come from that. Two details if you compare with another source:
- Every rep in the snapshot counts. Sources ranking only the top twenty or fifty measure shares against a smaller total, so they hit the threshold sooner and report a lower number.
- Each rep counts for the weight it held at the time, so later growth does not rewrite last week's figure.
Weights are a share of online stake.
Hosting
Reps at the same provider are not independent. They go offline together when that provider fails, whoever runs them.
The Nakamoto page charts weight and node count per provider, resolved from each node's IP. A provider holding a few large nodes is a concentration risk. One with many small nodes is not.
What moves it
It rises when weight moves from large reps to smaller ones. It falls when weight concentrates, or when a rep near the top goes offline and its weight leaves the online total.
Holders move it by changing representative. No protocol change or vote required. The health score helps find one worth moving to.