Selfish Mining

Selfish Mining, a.k.a a ‘block withholding attack’ is a type of economic attack vector in blockchain systems. In this attack, a mining pool delays their release of a discovered block so to attempt to secretly mine further blocks, while the rest of the network wastes energy mining what will become an orphan block. The attack is possible in part because the valid chain is identified by its length, not just time of publishing, so the selfishly mining pool could theoretically publish a longer chain after the initial block is discovered by other miners.