51% attack on Ethereum more difficult than on Bitcoin — Justin Drake

Ethereum’s Merge architect, Justin Drake, claims a 51% attack on Bitcoin would be cheaper than on Ethereum, estimating the cost at around $10 billion. This echoes Grant Hummer’s assertion that a successful attack on Bitcoin is “virtually certain” if the cost drops to $2 billion. A 51% attack grants control over a blockchain network by controlling over 50% of its mining or staking power.

Drake highlights the significant difference in cost due to Ethereum’s proof-of-stake (PoS) mechanism. Currently, half of all staked Ether (ETH) is worth approximately $44.8 billion. While a 51% attack on Ethereum would require a substantial investment – nearly 14.2% of its market cap – the cost would likely be far higher than Bitcoin’s due to the value of the staked ETH and the likely price increase caused by such an attempt.

However, Ethereum possesses additional defense mechanisms. Matan Sitbon, CEO of Lightblocks, emphasizes Ethereum’s strong social and economic coordination mechanisms as a crucial security layer. Drake further points out that the PoS system allows the community to identify and penalize attackers, a capability absent in Bitcoin’s proof-of-work (PoW) system.

This “social slashing” feature, along with the possibility of a community-led fork to replace a compromised chain, represents a significant advantage for Ethereum in the event of a 51% attack. While a 51% attack remains theoretically possible for both Bitcoin and Ethereum, the practical barriers are exceptionally high. For Bitcoin, the massive computing power and energy requirements make a sustained attack highly improbable. For Ethereum, the PoS mechanism introduces substantial economic and governance deterrents. The debate on the feasibility of such attacks, therefore, remains complex and nuanced.