The idea of the longest chain being the one that takes precedence Dynamic Availability No notion of finality, though typically ~6 blocks is seen as a safe amount to prevent a reorg. This number solely depends on number of malicious validators, as shown in some paper ( [[Scalable and Probabilistic Leaderless BFT Consensus Through Metastability]] ) synchronous, where the required difficulty of PoW is dependent on max network delay the number of required blocks for a transaction increases exponentially with the number of adversarial nodes, with an asymptote at f = n/2 wherein the number is infinte