Beacon Chain Suffered The Longest Blockchain “Reorg” In Years

Beacon chain suffered the longest blockchain reorganization in years and in today’s Ethereum news, we find out more about what it means and why it posed a security risk.

The ethereum beacon chain will be crucial for the Ethereum merge scheduled for later this year and it experienced a high-level security risk known as a blockchain reorganization. The reorganization can happen via a network failure like a bug or a malicious attack which results in a duplicate version of the blockchain. The longer the reorganization lasts, the biggest the consequences get. Beacon Chain suffered a major reorg with seven blocks, the largest in years according to Martin Koppelmann who is the CEO of the DeFi service provider Gnosis.

The Ethereum beacon chain experienced a 7-block deep reorg ~2.5h ago. This shows that the current attestation strategy of nodes should be reconsidered to hopefully result in a more stable chain! (proposals already exist) pic.twitter.com/BkQrKuUlw1

— Martin Köppelmann 🇺🇦 (@koeppelmann) May 25, 2022

The Beacon Chain was launched in 2020 and introduced native staking to the Ethereum blockcahin. The staking process involves pledging assets to the network which is how validators will become eligible to add more blocks to the chain and a main tenet of the PoS consensus model. The ethereum Merge referred to as “Ethereum 2.0” is a long-awaited upgrade to the current network and will make the transition from PoW to PoS so the merge is scheduled for August and will combine the Beacon Chain with the ETH mainnet.

A reorg happens when two different miners start working on adding blocks of transactions with similar difficulty to the chain at the same time which creates a fork and duplicates the version of the blockchain. A miner adding the next block has to choose which side of the fork will be correct so once they’ve done it, the other one is lost.  A seven-block reorg means that the fork was dropped and had seven blocks worth of transactions added to the network before it was decided tht it wasn’t a canonical chain. Each block on the chain contains about 200 to 300 transactions and has a value of 2 ETH.

As long as truth-seeking results in action and not just commentary

— Chris 🦇🔊🏴 (@slf_svrgn) May 25, 2022

The software that miners use has a method for determining which side of the fork to choose. The ETH founder Vitalik Buterin chimed in and added that the problem was caused by miners that run outdated versions of the mining software. Buterin and the CTO of Paradigm tackled the issues of reorgs in a blog post, saying that a reorg of more than five blocks is a sign of a malicious attack. They explained that one and two block reorgs happen all the time because of the latency of the network:

“Occasionally, bad luck can lead to 2-5 block reorgs. Reorgs longer than that are almost always due to extreme network failure, client bugs, or malicious attacks.”