{"id":186283,"date":"2018-10-24T11:05:25","date_gmt":"2018-10-24T15:05:25","guid":{"rendered":"https:\/\/insidebitcoins.com\/news\/five-successful-51-percent-attacks-have-earned-cryptocurrency-hackers-20-million-in-2018\/186283"},"modified":"2021-08-06T08:06:04","modified_gmt":"2021-08-06T12:06:04","slug":"five-successful-51-percent-attacks-have-earned-cryptocurrency-hackers-20-million-in-2018","status":"publish","type":"post","link":"https:\/\/insidebitcoins.com\/news\/five-successful-51-percent-attacks-have-earned-cryptocurrency-hackers-20-million-in-2018","title":{"rendered":"Five Successful 51 Percent Attacks Have Earned Cryptocurrency Hackers $20 Million in 2018"},"content":{"rendered":"
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According to trusted cybersecurity firm Group-IB, 51 percent attacks on cryptocurrency projects are on the rise. Thus far in 2018, the firm has tracked 5 successful 51 percent attacks, with hackers claiming almost $20 million in profits, The Next Web<\/em> reports<\/a>.<\/p>\n This is the first time we have seen a series of 51 percent attacks in crypto. Group-IB could not find a report of a single instance of a 51 percent in 2017. The full Group-IB report reveals that the total $19.5 million stolen from unsuspecting cryptocurrency projects this year largely took place between April and June.<\/p>\n One of the biggest threats to traditional blockchain networks, a 51 percent attack occurs when a single entity takes control of over 50 percent of the overall mining power in a Proof-of-Work (PoW) blockchain<\/a>.<\/p>\n \u201cThey\u00a0can be either carried out by one miner with a large number of computers or a group of miners forming a mining pool,\u201d Group-IB told\u00a0The Next Web<\/em>. \u201cControl over 51-precent [sic] of the network power itself is not necessarily an attack \u2014 unless there has been intentional use of this advantage.\u201d<\/p>\n Once control over a network\u2019s hashrate is achieved, hackers can wreak havoc by stopping transaction verifications, suspending mining, and preventing other miners from verifying transactions. A 51 percent attack also highlights one of the biggest risks in digital money systems: double-spending.<\/p>\n Double spending is the process by which a single digital token can be spent more than once. It is in many ways similar to creating counterfeit money. In the case of a 51 percent attack, hackers can create entirely unique blockchains, hidden from view, wherein they can freely verify false transactions. Group-IB told\u00a0The Next Web<\/em> that this is the greatest threat to PoW blockchains.<\/p>\n \u201cIt is possible to double spend even without controlling this much network power,\u201d Group-IB explains. \u201cHowever, control over 51-percent is an absolute guarantee that the fraudster\u2019s block is recognized as correct.\u201d<\/p>\n In 2018, hackers successfully attacked and subsequently crippled a number of small altcoin projects. A bug in Verge was used by hackers in both April and May to cash out more than a million dollars worth of cryptocurrency, while at the same time refusing to process other token holder transactions.<\/p>\n In June, Zen cryptocurrency lost $550,000 through a 51 percent attack that lasted only 4 hours. A similar attack happened to Litecoin Cash later that month.<\/p>\n However, the biggest attack this year was on Bitcoin Gold, which lost 388,000 BTG<\/a> ($18 million) in May after a \u201cmalicious miner\u201d took control of the BTG network. The attack quickly resulted in US-based exchange Bittrex<\/a> delisting\u00a0Bitcoin Gold from its exchange due to security concerns.<\/p>\n \u201cCybercriminals can get high rewards and steal lots of money by attacking small and unknown cryptocurrencies,\u201d a Group-IB spokesperson told Hard Fork<\/em>. \u201cIt is just technically easier to compromise relatively unknown cryptocurrencies, which usually do not have the capacity for the rapid response necessary to stop the\u00a0attacker converting stolen funds to a more stable currency.\u201d<\/p>\n The Next Web<\/em> reports that planning a 51 percent attack requires a large investment on the part of hackers. These funds are usually garnered from traditional mining rewards. In the case of the ZenCash attack, hackers needed at least $30,000 to snatch the over half million dollars from the attack.<\/p>\n A website specializing in how much it would cost hackers to execute 51 percent attacks on some of the biggest crypto networks reveals some shocking statistics. According to crypto51.app<\/a>, an attacker could take control of the Bitcoin hashrate for an hour for only $530,000 and Ethereum for just $150,000.<\/p>\n Group-IB recommends that the best defense for smaller crypto projects wanting to protect themselves against a 51 percent attack is to use encryption algorithms not typically adopted by large virtual currencies.<\/p>\n \u201cThis would allow to avoid the scenario where a mining pool is compromised and has negative effects on other cryptocurrencies that use the same algorithms,\u201d Group-IB concludes.<\/p>\n The post Five Successful 51 Percent Attacks Have Earned Cryptocurrency Hackers $20 Million in 2018<\/a> appeared first on UNHASHED<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"51 Percent Attacks in 2018<\/strong><\/h3>\n