According to the latest research from crypto intelligence company Coin Metrics, the attack has become unprofitable as the cost of attack has increased to astronomical figures as the scale of the blockchain increases. In other words, the current Bitcoin and Ethereum networks are immune to 51% and 34% attacks based on the consensus mechanism.
Table of contents
ToggleWhat are 51% and 34% attacks?
51% attack
First of all, 51% attack is a potential attack method against blockchain networks operating based on the Proof of Work (PoW) consensus mechanism.
By controlling more than 51% of the computing power, a single entity or organization changes the entire network mechanism, including modifying the transaction sequence, preventing transaction verification, executing a Double spend attackSpend Attack, etc., thus destroying the security of the network. sex and credibility.
Generally speaking, as a blockchain network continues to grow in size, the likelihood that one person or group will acquire enough computing power to overpower all other validators or participants will rapidly decrease.
At the same time, since each block is linked through cryptographic verification, the cost of modifying earlier confirmed blocks will also increase over time.
34% attack
In addition, the 34% attack is an attack method targeting blockchains that operate based on the Proof of Stake (PoS) consensus mechanism, using the pledge mechanism in the blockchain to attack.
In this attack, the attacker controls the operation of the network by staking more than 34% of the total tokens on the network, and conducts attacks similar to the above.
The above two attacks are serious security threats that will interfere with the operation mode of the blockchain, erode trust and cause heavy losses.
Previously, Ethereum Classic (ETC) and Bitcoin Cash (BSV) have also suffered multiple 51% attacks, with a total loss of more than one million US dollars.
(Extended reading: Strongly oppose EIP-1559! Miners will demonstrate force on April 1st, aiming to gather 51% of the computing power )
Coin Metrics: BTC and ETH networks are immune to 51% and 34% attacks
According to a report submitted by Coin Metrics on the 15th, the current 51% and 34% attacks on the Bitcoin or Ethereum networks are no longer feasible because the attack costs are extremely high and the profits are extremely low.

It is understood that the report introduced a new indicator called "Total Cost of Attack (TCA)", which aims to accurately quantify the cost expenditures related to the attack, and stated:
Even though the costs and benefits involved in carrying out these attacks are still difficult to accurately estimate, initially it seems that attacking the Bitcoin or Ethereum networks is unprofitable, which has eliminated the financial motivation of malicious attackers.
Bitcoin 51% attack costs more than $20 billion
By counting current market data and computing power, Coin Metrics believes that a 51% attack on Bitcoin would require the purchase of approximately 7 million mining machines at a cost of approximately US$20 billion, and the market actually does not have enough equipment to do so. sale.
In addition, even if there are entities that can produce mining machines on their own, the huge manufacturing costs will exceed US$20 billion.
Ethereum 34% attack costs more than $34 billion
In addition, Coin Metrics also found that the 34% attack on Ethereum is also quite impractical, not only costly, but even extremely time-consuming.

The article explains that the large-scale growth of on-chain Liquidity Staking Service (LSD) providers, including Lido, has caused concerns among Ethereum network participants and may pose a threat to the decentralization of the network.
However, Coin Metrics stated that due to the limitations on the amount of a single pledge on the Ethereum network, launching a 34% attack on the network will take at least 6 months to achieve:
This will cost more than $34 billion, and the attacker will need to manage more than 200 nodes through AWS services, costing more than millions of dollars.
Finally, the research team also emphasized in its conclusion:
Of all the attacks hypothesized in the experiment, even through the most profitable double spend attack, the attacker could only earn only $1 billion after spending $40 billion. Taking all costs into account, the attacker would only earn $1 billion. The rate of return is extremely low.
He added, "The current development scale and status of Bitcoin and Ethereum have made the above attacks economically unfeasible."

