According to Samson Mow, CEO of JAN3, a report released last month by Trail of Bits, a security firm based in New York City, contains a number of flaws and false assumptions about Bitcoin. The report named “Are Blockchains Decentralised? Unintended Centralities in Distributed Ledgers” looks at topics such as The Nakamoto Coefficient, Consensus Centrality leading to Mining Pool Vulnerabilities as well as Sybil and Eclipse Attacks.
However, as Samson Mow pointed out, some of the conclusions from the report are flawed. One of such conclusions is that if the mining pools are treated as centralized entities, then it is possible for just a handful of them to allow malicious actors to take control of the Bitcoin network.
According to Mow, events such as these are highly unlikely with their probability being near zero. While Mow does not deny that a small number of mining pools can in theory comprise a 51% attack on the Bitcoin network, he adds that a critical point is that the miners can change pools in an instant.
The feasibility of taking control of 4-5 pools and mounting an attack with no pool operator and no miner noticing is near zero. Any attack would need to be an ongoing and prolonged initiative during which miners would not be paid. Good luck with that.
A 51% Attack Is Nothing but Fear Mongering
Mow also specifies that even if there is a pool operator that is malicious, colluded to attack, or is careless and was taken over, the miners would quickly switch away. On top of that, Mow adds that it takes an immense amount of energy to mount a 51% attack, depending on how far back one would want to attack the chain.
In case the attacker would want to do so, usually they would want to have a goal as to why they decided to attack. The incentive could be a double spend, but Mow explains that any significant double spend execution would be immediately noticeable, which means that everyone would be able to see it coming. Thus, a 51% attack on the Bitcoin network is not a serious threat to Bitcoin, but can be used for fear mongering and confusing those unfamiliar with how mining pools and a 51% attack operate.