Simple model of an internal PoW attacker

Vlad Zamfir
Mar 20, 2017 · 6 min read

The external attacker

The “internal attacker”

Taking a look at the number of months until attack for internal attackers with advantage 5%, 10% and 25% per month, and with initial hashpower of 10%, 20% or 30% of the network. PSA: I rounded to the nearest month.

So how much security do we have, in this model?

The number of months that an adversary with weight 10%, 20%, or 30% would be delayed in their attack due to a doubling in block rewards, given that they have a 5%, 10%, or 25% advantage. This assumes that the network hashrate doubles in response to the doubling of the hashrate (reasonably, under the competitive market assumption).

Concluding thoughts

Vlad Zamfir

Written by

Absurdist, troll.

Welcome to a place where words matter. On Medium, smart voices and original ideas take center stage - with no ads in sight. Watch
Follow all the topics you care about, and we’ll deliver the best stories for you to your homepage and inbox. Explore
Get unlimited access to the best stories on Medium — and support writers while you’re at it. Just $5/month. Upgrade