Selfish Mining(Selfish Mining) Study Guide
Selfish mining is a strategy in which miners temporarily withhold newly discovered blocks, first building a private chain branch, and then publishing it at an opportune time to seek more block rewards. It shows how proof-of-work incentives may theoretically be exploited and may affect network fairness and decentralization.
Basic Principles
Under normal circumstances, after finding a new block, a miner broadcasts it immediately and receives the block reward once the network confirms it. A miner adopting Selfish Mining temporarily hides the newly discovered block and continues mining on a private branch while other miners contribute hash rate to the public chain. The aim is not to directly alter the rules, but to gain an advantage by exploiting the timing of block publication.
How the Private Chain Gains an Advantage
Miners attempt to keep the private branch at least one block ahead of the public chain and publish it at an appropriate time. Nodes generally accept the chain with more cumulative proof of work, so a longer private chain may replace the original public chain. The replaced public blocks are discarded; their transactions may be rolled back, and the resources previously invested by other miners are wasted.
Success Conditions and Theoretical Thresholds
Whether this strategy is profitable depends both on luck and on the proportion of the network’s hash rate controlled by the miner, block propagation speed, and the reactions of other miners. Theoretical models often mention that controlling approximately 25% or more of the total hash rate may create room for profit, but this is not a fixed threshold that guarantees success in reality; practical feasibility remains constrained by network conditions.
Implications for Network Security
If selfish mining remains effective over the long term, hash rate may gradually concentrate in a small number of mining pools, thereby weakening the decentralization of Bitcoin and becoming associated with the broader 51% attack risk. However, centralization may also damage the value of the assets received by miners, so many observers believe that honest participation generally better serves the long-term interests of most miners.
Original Tutorial
https://www.binance.com/en/academy/glossary/selfish-mining