Inertial Mining: Equilibrium Implementation of the Bitcoin Protocol

2026-04-07

AI Summary

This work addresses the vulnerability of Bitcoin’s original mining protocol, which fails to constitute a Nash equilibrium and is thus susceptible to strategic attacks such as selfish mining, thereby compromising system security. The authors propose an “inertial mining” protocol that preserves Nakamoto’s longest-chain rule while modifying miner behavior only in the presence of unexpected forks, without altering the underlying consensus architecture. Through game-theoretic modeling and equilibrium analysis, they demonstrate that this protocol achieves, for the first time, a Nash equilibrium compatible with the existing Bitcoin network under the condition that no miner controls more than 50% of the total computational power. Consequently, it fully eliminates the profitability of strategic deviations and effectively restores and ensures the system’s security and stability.

Abstract

The value of proof-of-work cryptocurrencies critically depends on miners having incentives to follow the protocol. However, the Bitcoin mining protocol proposed by Nakamoto (2008) and implemented in practice is well known not to constitute an equilibrium: Eyal and Sirer (2018) construct a profitable deviation called ``selfish mining'' which relies on strategically delaying disclosure of newly mined blocks rather than publishing them immediately. We propose inertial mining, a novel mining protocol. When miners follow inertial mining, they produce the outcome intended by Nakamoto, i.e., a single longest chain. But unlike the Bitcoin mining protocol, inertial mining constitutes an equilibrium (assuming no miner controls more than half of the mining power). Indeed, neither selfish mining nor any other deviation is profitable. Furthermore, inertial mining only changes miners' behavior in the event of off-path forks, and can be implemented in Bitcoin without any changes to its consensus mechanism or blockchain architecture.

Problem

• Bitcoin
• mining protocol
• equilibrium
• selfish mining
• incentive compatibility

Innovation

• inertial mining
• equilibrium
• selfish mining
• incentive compatibility
• blockchain consensus