Vitalik Buterin has suggested replacing the current finality component, Casper FFG, with a new mechanism called Minimmit in Ethereum's consensus discussions. According to Odaily, Buterin explained that Casper FFG uses a two-round finality process, requiring validators to sign twice for 'proof' and 'final confirmation.' In contrast, Minimmit achieves finality with just one round of signatures. As a trade-off, Minimmit's fault tolerance threshold would decrease from Casper FFG's 33% to approximately 17%.
Despite the reduced fault tolerance, Minimmit is more likely to lead the network into a 'multi-chain competition' rather than an erroneous final confirmation in various attack or client bug scenarios. This situation is easier to recover from through community coordination. Buterin believes that avoiding finality for a short period is safer and more recoverable than having incorrect blocks finalized, suggesting that Minimmit may offer a better overall security balance.