The Ethereum blockchain experienced a temporary loss of block finality last week, leading to confusion and raising concerns about the blockchain’s functionality and security. While blocks not finalizing in Ethereum doesn’t usually cause downtime or affect end-user experience, it can lead to security issues like reorgs – when a blockchain creates more than one block at the same time due to a bug or attack.
The cause of this loss of block finality is still under investigation, with provider Prysm releasing a new version of their client software that includes critical fixes. While not considered dire, the incident had a snowball effect that impacted end-users; for instance, leading crypto exchange platform DYdX temporarily paused deposits, and Polygon’s zkEVM experienced delays with their deposits.
To give some context, finality in a blockchain is reached when transactions are considered immutable and blocks containing transactions cannot be altered. In Ethereum’s proof-of-stake blockchain, validators first propose a block containing transactions, and other validators sign off on the block to permanently add it to the blockchain – this process takes around 15 minutes. However, the Ethereum community acknowledges that the current timeframe for blocks to be finalized is too long, allowing opportunities for attacks and reorgs.
The incidents last week marked Ethereum’s first-ever inactivity leak – an emergency state triggered when finality cannot be guaranteed, applying penalties to validators and incentivizing the blockchain to finalize. Ethereum co-founder Vitalik Buterin has been discussing the importance of finality for years, indicating it’s an ongoing problem that needs resolution.
In an effort to address these issues, Ethereum developers were quick to respond to the first loss of finality on May 11, taking only 25 minutes to resolve the problem. However, the following day, the chain stopped finalizing again, causing outages for some infrastructure providers.
Despite the unpleasant experience, Ethereum developers maintain that the network did not go down and that its security or soundness remained uncompromised. These incidents have exposed areas that need improvement and raised awareness of the importance of creating a more resilient Ethereum network.
Going forward, developers will continue to investigate the causes of the blockchain
Source: Coindesk
