Author: Gregory Maxwell 2013-04-05 09:52:14
Published on: 2013-04-05T09:52:14+00:00
In an email to the Bitcoin development mailing list, Melvin Carvalho brought up concerns about a mining pool having reached 46%. However, he noted that the estimates on blockchain.info may be lossy. The discussion then shifted to the risk of a 51% attack, with Carvalho suggesting that a decentralized pool would prevent such an attack. However, it was pointed out that none of the pools listed on blockchain.info are meaningfully decentralized and that pool owners have control over what goes into the block. The main threat is not that pool owners do something bad but that their systems get hacked or they are subjected to coercion. While it may be almost impossible to coordinate a 51% attack by the owner due to random non-colliding nonces, miners have freely dumped all their hash power on questionable parties without considering the risks. It's important to understand what kind of threat you're talking about as someone with a large amount of hash-power can replace confirmed blocks with an alternative chain that contains different transactions, allowing them to claw back funds that had already triggered irreversible actions. An attacker with only 40% of the hashpower can reverse six confirmations with a success rate of ~50%.
Updated on: 2023-05-19T16:42:59.535323+00:00