How much money do you need to spend to perform 51% attacks on Bitcoin and Ethereum?

A 51% attack occurs when a single network miner or group of miners controls more than half of the blockchain network's hash volume. In theory, this would allow an attacker to block transactions in the blockchain, change the order of new transactions, and reverse past transactions (called “double spending”) by corrupting the blockchain information.

However, according to a recent study, it is financially impossible to carry out such attacks in the current security settings of Bitcoin and Ethereum.

Attacking Bitcoin and Ethereum is not worth it

In the year Referring to December 31, 2023, and an Ethereum price of $2,279, a total amount of ETH of 28.8 million ETH and a verification count of 899,840 validators, CoinMetrics calculations suggest that an attacker would need around $34.39 billion to execute 34. % Attack on the network.

If the attack was launched on December 31, 2023, it would take the attacker until June 14, 2024 to breach the 33 percent threshold to gain control of the network.

Attacking Bitcoin also proves far-fetched. Researchers estimate that the attacker will need to produce about 40 million S9 units, which will cost more than $20 billion to produce.

Using a more powerful ASIC like the upcoming Bitmain S21 will cost around $5.6 billion by December 2023, about a quarter of what it would cost to use the S9. This estimate is based on a price of $2,240 and a production volume of 2.5 million machines.

While more cost-effective than the “mild” approach, the study found that manufacturing at this scale and efficiency requires collaboration with the manufacturer. However, the attacker will likely face supply chain problems and potential retaliation.

“Our findings show that the security situation in Bitcoin and Ethereum makes attacks economically unfeasible and provide concrete evidence of Nash equilibrium in these networks.”

The study found that the costs and risks associated with 51% of Bitcoin and Ethereum security measures far outweighed the benefits. This suggests that hostile actions become less attractive compared to alternative strategies such as loyal participation in the network or refraining from attacking.

51% of attacks extend beyond the leader block chain

The assessment may be true for top blockchains like Bitcoin and Ethereum, but the same cannot be said for many other networks that have been created in the last decade.

Bitcoin SV, a blockchain that split off from Bitcoin Cash and is primarily backed by entrepreneurs Calvin Eyre and Craig Wright, has experienced three attacks with 51% of attacks in 2021. Similarly, the lesser-known privacy-focused crypto Firo, formerly known as Zcoin. He suffered the same fate. Even Ethereum Classic has not been spared by fraudulent actors.