The Ethereum protocol recently experienced two incidents in which its Beacon Chain stopped finalizing blocks. This occurred on May 11, 2023, when the network was unable to fully confirm transactions for about 20 minutes and again on May 12, 2023, for over an hour.

Generally, block finality refers to a state where a supermajority of validators have attested to the final state of the blockchain, guaranteeing that a block and its processed transactions cannot be modified or eliminated from the blockchain.

Block finality implies that a block of data has been added to a blockchain with some negligible probability of being reversed or altered. Blockchains like Bitcoin and Ethereum show probabilistic transaction finality in that transactions are not automatically or instantly final, but the probability of being reversed decreases as more blocks are added to the chain.

During the two finality incidents, Ethereum end users successfully continued to transact on-chain through the incident. Ethereum Developers released patches to resolve the block finality incidents but said an analysis was underway to determine the root cause of the problem. 

In a May 21, 2023 blog, Ethereum co-founder Vitalik Buterin cautioned against overloading Ethereum consensus beyond its core functions of validating blocks and securing the network, as this could bring high systemic risks to the ecosystem. In the same blog, Buterin called for preserving the chain’s minimalism and helping developers find alternate strategies to achieve their security goals.

The Ethereum protocol has undergone several major upgrades and improvement plans to make it more robust and reliable.

In September 2022, the Merge upgrade was implemented. In the Merge, the Ethereum protocol moved from its original proof-of-work mechanism to a proof-of-stake mechanism. The merge aimed to make the Ethereum protocol less energy-intensive, more secure, and better suited to implementing new scaling solutions.

In November 2022, Buterin outlined an updated Ethereum protocol roadmap in line with its vision of enhancing scalability, security, and sustainability. Buterin said that the Ethereum protocol is undergoing several system upgrades and will ultimately enter a state of relative stability that optimizes safety and predictability.

According to Buterin, the Ethereum protocol roadmap consists of six parallel running upgrades: the Merge, the Surge, the Scourge, the Verge, the Purge, and the Splurge.

Another upgrade known as the Ethereum ‘Shapella’ upgrade was implemented in April 2023. The Shapella upgrade enabled stakers to unstake ETH and validators to withdraw previously staked ETH. The Shapella upgrade was implemented with other Ethereum Improvement Proposals, including reducing gas fees during peak network periods.