# Majority is not Enough: Bitcoin Mining is Vulnerable

Source: [Majority is not Enough: Bitcoin Mining is Vulnerable](<https://www.sota2.com/research/paper/68fa61291e209131ce9f2d40>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T19:53:34.667Z

Authors: Ittay Eyal, Emin Gun Sirer

Published: 2013-11-01T18:15:21.000Z

## Abstract

The Bitcoin cryptocurrency records its transactions in a public log called the blockchain. Its security rests critically on the distributed protocol that maintains the blockchain, run by participants called miners. Conventional wisdom asserts that the protocol is incentive-compatible and secure against colluding minority groups, i.e., it incentivizes miners to follow the protocol as prescribed.   We show that the Bitcoin protocol is not incentive-compatible. We present an attack with which colluding miners obtain a revenue larger than their fair share. This attack can have significant consequences for Bitcoin: Rational miners will prefer to join the selfish miners, and the colluding group will increase in size until it becomes a majority. At this point, the Bitcoin system ceases to be a decentralized currency.   Selfish mining is feasible for any group size of colluding miners. We propose a practical modification to the Bitcoin protocol that protects against selfish mining pools that command less than 1/4 of the resources. This threshold is lower than the wrongly assumed 1/2 bound, but better than the current reality where a group of any size can compromise the system.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

- [Revenue Ratio Analysis on Blockchain Mining MDP Model gamma=0](<https://www.sota2.com/research/sota/revenue-ratio-analysis-on-blockchain-mining-mdp-model-gamma-0.md>): Revenue Ratio Analysis; Blockchain Mining MDP Model gamma=0 (Evaluation); Revenue Ratio: 0.78255.

- [Selfish mining threshold calculation on Selfish Mining Profitability Simulation various configurations 1.0](<https://www.sota2.com/research/sota/selfish-mining-threshold-calculation-on-selfish-mining-profitability-simulation-various-configurations-1-0.md>): Selfish mining threshold calculation; Selfish Mining Profitability Simulation various configurations 1.0; Simulation Threshold: not recorded.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1311.0243>)

[PDF](<https://arxiv.org/pdf/1311.0243.pdf>)