According to Cointelegraph, Ethereum architect Justin Drake expressed concerns about the relative security of Bitcoin compared to Ethereum. Drake, who played a pivotal role in Ethereum's transition to a Proof of Stake (PoS) system, suggested that launching a 51% attack on Bitcoin would be more cost-effective than on Ethereum. He estimated that the cost of such an attack on Bitcoin could be around $10 billion. This view aligns with a previous statement by Janet Hammer, co-founder of Etheralize, who claimed that Bitcoin's security budget is insufficient. Hammer estimated that a successful 51% attack on Bitcoin could cost $8 billion, potentially dropping to $2 billion in the future. A 51% attack occurs when an entity controls more than half of the mining or staking power of the blockchain network, allowing them to manipulate the network.
Drake delved into the challenges of executing a 51% attack on Ethereum, noting that achieving 100% control would require more than half of the staked Ether. At the time of his comments, there were over 34 million Ether staked, valued at approximately $89.6 billion. This means that obtaining the necessary stake would cost around $44.8 billion. Given Ethereum's market value of $316 billion and a 24-hour trading volume of $25 billion, the financial requirements for such an attack are substantial. Moreover, any attempt to accumulate this amount of Ether would likely drive up its price, increasing the attack's cost.
Matan Sittbon, CEO of Light Blocks, pointed out additional security measures in Ethereum, emphasizing the role of social and economic coordination mechanisms in the community. Drake also noted that Ethereum's Proof of Stake (PoS) system allows the community to identify and penalize attackers through social consensus, a feature not available in Bitcoin's Proof of Work (PoW) system. This social layer, consisting of human participants in the network, can decide on software changes to counter attacks. Pavel Yashin from P2P.org mentioned that if centralization is detected, the community can implement a new fork, rendering the compromised chain invalid. Hassan Khan, CEO of Ordez, added that while a 51% attack is theoretically possible, practical barriers make it highly unlikely for both Bitcoin and Ethereum. He noted that Bitcoin's Proof of Work (PoW) system requires significant energy and computations, while Ethereum's Proof of Stake (PoS) presents economic and administrative challenges that prevent such attacks.
