Bitcoin And Ethereum Blockchains Are Not Protected From 51% Attack
On January 5, 2019, the Ethereum Classic (ETC) cryptocurrency blockchain was under 51% attack. Could the similar incidents happen in the future again? Leading experts in the blockchain industry have expressed their opinion on this issue.
Blockchains Are Not Protected From 51% Attacks
The president of Blockchain at Columbia, Nir Kabessa, believes the main goal of 51% attack is an attack on blockchain of popular cryptocurrencies. However, an attack on Bitcoin and Ethereum, will require large capital investments and coordination of several large mining pools actions. Hashrate of ETC is about 22 times less than the Ethereum network one (8 TH/s versus 177 TH/s). That's why the 51% attack on the Ethereum Classic blockchain costs 22 times less than the attack on the Ethereum network. According to Crypto51, the 51% attack on ETC blockchain costs about $ 4.722, and on ETH network - $ 102.509.
“Proof of Work” Consensus Protocol Is Not Safe
Co-founder of Qtum blockchain startup, Jordan Earls, reported a low security level of the proof-of-work consensus protocol. In his opinion, 51% attacks are preventable by applying a proof-of-stake protocol in the blockchain. Jordan claims that proof-of-stake has a much higher level of security than PoW. His words confirmed by the facts: all successful 51% attacks directed against blockchains that operated on the basis of the "proof of work" protocol.
51% Attack On Bitcoin And Ethereum Blockchains Is Unlikely
Mati Greenspan, a Senior Market Analyst eToro, believes that a 51% attack on the Bitcoin and Ethereum blockchains is unlikely. According to him, the main target of the attackers is cryptocurrency networks have a low hashrate. Grispan is sure that no one will be able to concentrate enough computing power to conduct a successful attack on TOP blockchains of digital assets.
As a result, the attackers managed to reorganize 15 blocks and earn $ 1.1 million due to 51% attack on Ethereum Classic. The amount of profit from the attacks on Ethereum and Bitcoin is a big question and depends entirely on the duration of its implementation. It is much more profitable to attack blockchains of less popular digital assets.