Ethereum (ETH) Merge architect Justin Drake says it would be cheaper to launch a 51% attack on Bitcoin than on Ethereum.

Justin Drake, architect of Ethereum's proof-of-stake (PoS) implementation, told Cointelegraph that it would be cheaper to launch a 51% attack on Bitcoin than on Ethereum.

It would be cheaper to launch a 51% attack on Bitcoin (BTC) than on Ethereum (ETH), according to Ethereum Merge architect Justin Drake.

Speaking to Cointelegraph, Drake said that it would be “much cheaper to 51% attack Bitcoin” and that it would cost “on the order of $10 billion.”

Drake led work on Ethereum’s proof-of-stake (PoS) implementation and was a principal architect in the Merge (the full PoS transition event). His remarks echo a May 14 X post by Grant Hummer, the co-founder of Ethereum-focused marketing and product company Etherealize.

In the post, Hummer said that Bitcoin “is completely screwed because of its security budget.”

Hummer claimed it would cost $8 billion to run a successful 51% attack and that a successful attack is “virtually certain” when the cost slips to $2 billion. A 51% attack occurs when a single entity or group controls over 50% of a blockchain network’s mining or staking power, gaining power over the network. Hummer added:

If the cost drops below $1 billion (about half of what they spend yearly on salaries!), they could easily maintain control of the chain for years. At that point, they could steal all the remaining tokens.

Ethereum attack would cost much more

Drake said that “to have 100% control of the chain, you need 50% + 1 of stake.” He said that it would be extremely difficult and expensive, but far from impossible:

It would be cheaper to 51% attack Bitcoin.

At the time of writing, there were 34,168,987 staked Ether (ETH) worth nearly $89.6 billion. Consequently, half of all ETH has a current value of almost $44.8 billion.

Still, a much higher investment would likely be needed. Ether has a current market cap of $316 billion and a 24-hour trading volume of $25 billion (just over 8% of the market cap).

The ETH needed for an attack is worth nearly 14.2% of the market cap and 180% of the 24-hour trading volume. An undertaking of that size would likely cause significant ETH price appreciation, further increasing the cost of the attack.

Related: Coin Metrics research shows BTC and ETH are immune to 51% attacks

Ethereum’s last line of defense

Matan Sitbon, the founder and CEO of blockchain interoperability developer Lightblocks, told Cointelegraph that Ethereum has an additional feature to defend against such attacks.

“Ethereum’s ultimate security lies not solely in cryptography or protocol rules, but in the community’s powerful social and economic coordination mechanisms,” he said.

Drake also highlighted another advantage that he claims Ethereum has over Bitcoin. He explained that “if there is a 51% attack, the social layer can identify the attacker and socially slash it.”

“This is a superpower of PoS that is not available with PoW,” he added.

Drake’s statement refers to the social layer, meaning the network’s human supermajority, which decides which software to run. Bitcoin’s simpler proof-of-work (PoW) consensus mechanism has a smaller attack surface and longer reliability track record, but it lacks this feature.

Pavel Yashin, Researcher at P2P.org, told Cointelegraph that “if the centralization is detected,” the community could resolve it with a new fork. The old token would end up being delisted, and the compromised chain would fall into irrelevancy.

Hassan Khan, CEO at Bitcoin liquidity protocol Ordeez, told Cointelegraph that “the debate around the feasibility of a 51% attack remains open-ended — largely because while theoretically possible, in practice the barriers are extremely high.”

He said that for Bitcoin, the necessary amount of computing power and energy “makes a sustained attack highly improbable,” while for Ethereum, “PoS introduces additional economic and governance deterrents.”