Not sure about "selfish mining" per se... but there have been numerous "51% hashrate attacks" on various altcoins. A 51% attack is essentially just extended selfish mining, where the miner creates a nice long(er) chain in private until their goal is achieved and then they broadcast it... triggering blockchain re-organisations etc.
Thanks for the reply. Yes, it seems that compared to 51% attacks, selfish mining belongs mainly to the theoretical domain. Furthermore, to answer my point number 3, selfish mining seems to require a sort of cooperation of a good portion of the neutral network (so it cannot be done covertly), as described in the following 2013. article by Vitalik Buterin:Quote
Furthermore, unlike a standard 51% attack, which only becomes obvious after the fact, this economic attack would need to be announced in advance to let neutral miners know that they have the opportunity to join the attacking coalition for their own benefit.
Source: https://bitcoinmagazine.com/articles/selfish-mining-a-25-attack-against-the-bitcoin-network-1383578440/
Source: https://bitcoinmagazine.com/articles/selfish-mining-a-25-attack-against-the-bitcoin-network-1383578440/
This article also outlines a strategy as to when and how to decide to publish blocks (point number 2). The end result depends on the portion of the network (Z) willing to join the attacker's chain:
Quote
Suppose the attacker’s portion of the network hashpower is X, and when there are two competing public chains the portion of the network that picks up on the attacker’s chain is Z.
...
As Z decreases, the attacker’s advantage goes down; at Z = 0.5, Eyal and Sirer showed that the attacker becomes more efficient than the public network at X > 1/4, and if X > 1/3 the attacker is more efficient than the public network at any Z.
...
As Z decreases, the attacker’s advantage goes down; at Z = 0.5, Eyal and Sirer showed that the attacker becomes more efficient than the public network at X > 1/4, and if X > 1/3 the attacker is more efficient than the public network at any Z.
