Author: ZmnSCPxj 2020-07-01 16:58:24
Published on: 2020-07-01T16:58:24+00:00
In an email conversation between two individuals, the concept of weak and powerful miners is discussed. A miner is considered weak if its hashrate share is less than the ratio of Alice's fee to Bob's bribe fee. It is suggested that scorched-earth is a possible mitigation against this attack. Another analysis suggests considering miners as a breeding group with various strategies and seeing which one gains more utilons and outbreeds others. The non-myopic strategy is explained, whereby sacrificing the chance to include Alice's transaction gives an increased chance to confirm Bob's higher-fee timelocked transaction. The myopic miner has a 25% chance of confirming Bob's transaction later. Non-myopic miners sacrifice their fee earnings when they don't include Alice's transaction, and the myopic miner can impose costs on them by getting Alice's transaction confirmed and earning the bigger Bob fee. ZmnSCPxj warns that using this model, non-myopic miners can only maintain hold over the blockchain if all miners agree to use non-myopic strategy, which would lead to a cartel/monopoly. Such situations are detrimental to customers of the monopoly, and decentralization is preferred. Myopic Miners rely on bribery attacks but need all miners to be rational, hence considering their utility at game conclusion instead of myopically optimizing for the next block. If a portion of the miners are myopic, then any of them gets to create a block during the first T − 1 rounds, that miner would include Alice’s transaction and Bob’s bribery attempt would fail. However, even if Bob offers a bribe with an appropriately high feerate, the attack is unlikely to succeed. The probability of bribery failing decreases exponentially in T and depends on the number of blocks until timeout and the percentage of the hashrate controlled by so-called myopic miners. In a highly competitive environment, each miner works for themselves, leading to better services to the customers of the mining business.
Updated on: 2023-05-20T23:31:19.732138+00:00