Researchers at Crypto exchange Gate.io report that they confirmed that a 51% attack occurred successfully on the Ethereum Classic (ETC) blockchain. The company has published an analysis of their findings on January 8th.
Gate.io Research published its analysis of ETC transactions on its platform during the alleged attack, claiming it detected seven rollback transactions – four of which were reported to be conducted by the attacker, transferring a total of 54,200 ETCs in total (worth $ 271,500 at the time press).
Gate.io reports that the incident occurred in a 4-hour period between 0:40 and 4:20 Jan. 7, 2019 UTC, during which the transactions were normally confirmed on the blockchain and subsequently invalidated after the rollback of the malignant network. After providing details of three ETC addresses allegedly used by the attacker, Gate.io continues to explain:
"The censorship of Gate.io has been successfully blocked [the] the attackers' transactions at the start and sent them to [a] manual examination Unfortunately, during the 51% attack, all transactions seemed valid and confirmed well on the blockchain. The examiner has passed the transactions. Because of this attack caused a loss of about 40k of ETC. "
Gate.io states that it will offset the losses of its users, stating that "Gate.io will take all losses for users". The exchange also recommends other cryptographic platforms to block transactions arising from the identified suspect addresses. The exchange also claims to have increased the confirmation number of the ETC transaction to 500 and launched a 51% stronger security detection mechanism.
Today, January 9, the Chinese security company blockchain Slow Mist has also published a report that also confirms a 51% attack and containing the same rollback transactions reported by Gate.io.
As previously reported, several major cryptographic exchanges – Coinbase based in the United States and bitFlyer and Coincheck exchanges in Japan – have suspended all withdrawals and deposits of ETC as of January 5th. All exchanges have been moved to respond to unusual hashing activities that indicate a potential attack of 51%, as well as Coinbase's findings on double spending and "chain reorganizations".
ETC's development team initially responded by refuting that a 51% attack had occurred, stating that no double losses had been detected. At the time, they claimed that control of the majority of the network hashred was "most likely a selfish erosion", attributable to the testing of new 1.400 / Mh ethash machines by the manufacturer of application integrated circuits. specific (ASIC) Linzhi.
As reported, a 51% attack can occur on blockchains that use a proof-of-work (PoW) algorithm and essentially implies that a user or group takes control of most of the mining energy to monopolize the control on the network. This, in particular, can allow the agent for threats to reverse transactions with the intent of doubling spending – by making cryptography for fiat currency, and then restoring the act to recover the cryptography exhausted. , pocketing the fiat.
Although the theoretical risk of majority attacks exists, the almost total control of a large chain of blockchains is widely considered at the moment prohibitive. Bitcoin-based blockchain based on PoW has not yet been compromised by a hijacking of the network hashr, but some developers still have he made the case to investigate the potential change of PoW.