Ethereum co-founder Vitalik Buterin has clarified that the Ethereum network is robust enough to endure temporary losses of finality without significant risk. His comments follow a recent bug in the Prysm client that briefly disrupted the blockchain's confirmation mechanism. Buterin emphasized that the critical failure to avoid is the finalization of an incorrect block, not a temporary delay in finalization itself.
Buterin explained that finality represents the network's certainty that a block will not be reverted. He stated that occasional delays, even lasting hours due to a major bug, are acceptable as the blockchain continues to operate. The real danger lies in finalizing the wrong chain of transactions.
This perspective is supported by experts like Fabrizio Romano Genovese, a computer science PhD and Ethereum protocol expert. He noted that during a loss of finality, Ethereum temporarily operates more like Bitcoin, which has functioned with probabilistic finality since its inception. In such a state, the chain's security isn't compromised; instead, the guarantee against reorganizations (reorgs) becomes probabilistic rather than absolute.
However, this temporary shift can impact infrastructure reliant on deterministic finality, such as certain cross-chain bridges and layer-2 networks. For instance, the Polygon sidechain indicated that transfers from Ethereum might be delayed while awaiting finality, and its AggLayer would similarly pause cross-chain settlements. Crucially, these entities confirm that user transactions would not be invalidated or rolled back due to such an event.
Genovese pointed out that the responsibility for handling these delays falls on application developers. If a bridge or service chooses not to implement a fallback mechanism for temporary finality loss, that is a design choice, not a fundamental network flaw. This event underscores Ethereum's resilience and the nuanced understanding of finality within its evolving ecosystem.
