Selfish Mining

Basics

From Crypto Compare:

"Selfish mining is an attack on the integrity of the Bitcoin network. This is where one miner, or mining pool, does not publish and distribute a valid solution to the rest of the network.

The selfish miner then continues to mine the next block and so on maintaining its lead. When the rest of the network is about to catch up with the selfish miner, he, or they, then release here portion of solved blocks into the network.

The result is that their chain and proof of work is longer and more difficult so the rest of the network adopts their block solutions and they claim the block rewards."

From Micah Zoltu (22-8-2020):

"Another, less discussed, 51% attack against proof of work is censorship (AKA: selfish mining attack). In this attack, you have your 51% of hashing power mine blocks, but you refuse to build on any block that wasn’t mined by your mining coalition. Since you have decision making power over 51% of the hashrate, this means that your chain will be the longest (eventually), and any blocks mined by anyone not part of your coalition will be ignored. The end result is that you will receive 100% of the block rewards instead of 51% of the block rewards, which means you double your income without doubling your work."

History

First published about by Emin Gun Sirer (1-5-2020):

"And I, with my colleague Ittay Eyal, who is now a professor at Teknion, we found that Satoshi was wrong. Bitcoin is not perfect. In fact, you're better off not following Satoshi's prescribed protocol, but following a slight variant which gives you more coins. This was a mining strategy called selfish mining and then when we published this people went crazy. They attacked me, they attacked Ittay, I got all sorts of threats, all sorts of attacks. They crowdfunded a simulator to show us that we were wrong. And then the guy who wrote the simulator said well, they're right. Everything they said is correct. And the graph he drew is exactly the graph we drew. So it's really cute. This is why I love being a scientist.

There are a bunch of risks associated with engaging in any such thing. And so I'm not aware of anybody that has used it against Bitcoin. I do know that it has been used against other altcoins but not against Bitcoin because to do it right, you need a substantial number of mining rigs. So it's not trivial and it also requires know how, and until recently miners did not have the know how to do this. They were barely capable of running the code as given to them by the developers. They weren't able to develop much code themselves until quite recently. So I think we're going to see more attacks."