[ad_1]
Only two weeks after the new year and the cryptocurrency community is grappling with the reality of an alleged "51% attack" on the Ethereum Classic (ETC) blockchain.
Although there is not yet a clear idea of who is responsible for manipulating the ETC blockchain by controlling most of the CPU power in the mining pool, the circumstances raise some big questions about the safety and strength of the work trial algorithms (PoW).
It is worth taking a look at the chain of events that led to the confirmation that ETC had indeed been the goal of a blockchain reorganization.
On 7 January, ETC developers were alerted a possible attack on the network by the Chinese security company blockchain SlowMist, which was transmitted to the community on Twitter.
A tweet from the ETC handset on Twitter, which has been deleted since then, has suggested that testing of new 1400 / Mh ethash machines from the Linzhi-specific application-specific integrated circuit manufacturer (ASIC) could be a potential cause.
The ETC developers said the attack was "most likely a self-extracting job", noting that they had not detected any double spent at the time.
Following this, Coinbase also noted that what he described as a 51 percent attack. The company therefore suspended all ETC transactions.
Coinbase identified a "deep reorganization of the chain" of the ETC blockchain which included a double spending on Saturday 5 January. On the evening of 7 January, the company had made the balance of more double spend on the network:
"At the time of writing, we identified a total of 15 reorganizations, of which 12 contained double expenses, for a total of 219,500 ETCs (~ $ 1.1 million)."
The Coinbase team seems to have conducted a thorough blockchain analysis and provided specific examples of blockchain reorganization.
Crypto exchanges Coincheck is BitFlyer followed the example by announcing the interruptions of ETC transactions on their platforms.
On 9 January, SlowMist published a detailed 51% attack report, confirming the same chain reorganizations released by Coinbase and other transactions with Binance and Bitrue portfolios. Bitrue also confirmed the attack on Twitter.
SlowMist also believes that a concerted effort by all the exchanges involved could help identify the author:
"Through our intelligence analysis, the identity of the attacker can finally be localized if the relevant exchanges are willing to help."
The cryptocurrency exchange Gate.io also confirmed that it had collected at least seven double expense transactions after conducting its own investigation on the attack. Users of the exchange have been guaranteed to be reimbursed for any losses incurred.
Unpacking the reorganization of the blockchain
The idea of a 51% attack is not new, and there have been instances of this over the years – even though they have been popularized by the Hollywood sitcom Silicon Valley.
A blockchain attack using a PoW algorithm for consent is possible if attackers have more than 50% control of the network hash rate.
In this case, the CPU power of control will allow an attacker to create a separate chain from any previous block in the blockchain. Given that it has most of the computing power, its new chain will eventually exceed the accepted chain from the network, thus defining a new transaction history.
In this new chain, attackers are able to double virtual spending, which means that funds that have already been spent in the chain of the network could be spent again in the chain of attackers.
As Emin Gün Sirer, developer and professor at Cornell University, told Cointelegraph, a 51% attack is bad, but does not give aggressive power to attackers:
"Miners at 51% or more have many powers, but they do not have the ability to change the current system rules, nor can they usurp funds. They can rewrite the existing blockchain in a limited way: they can not introduce transactions that do not already exist, they can omit any transaction they want and certainly can not change any of the existing rules. "
The reality of consent
The consent to the job test requires a network of miners to process the transactions. This is clearly stated in the Bitcoin white paper by Satoshi Nakamoto, which also clarifies that more than half of the network must consist of so-called "honest" workers:
"If most of the CPU power is controlled by honest nodes, the honest chain will grow faster and higher than any competing chain."
Therefore, the vulnerability is inherently embedded in the PoW consent algorithms, as the network assumes that the mining nodes are honestly verifying the transactions. The evolution of the mining sector has seen the rise and domination of ASIC chips – as well as the accumulation of hash power by huge groups of mining pools, which therefore share the fruits of their combined work .
These large pools are potentially a threat to any cryptocurrency that uses PoW algorithms, as a concerted effort to group resources that could combine the hash rate on over 50% of the total network that gives them control. In this case, the network becomes centralized as a bank.
After ETC's attack, the founder of Litecoin (LTC), Charlie Lee, said that this vulnerability is a necessary weakness for a completely decentralized cryptocurrency:
"By definition, a decentralized cryptocurrency must be susceptible to 51% attacks if it has hashrate, stakes and / or other resources that can not be acquired without authorization, and if a cryptography can not be 51% attached, it is authorized and centralized."
Gun Sirer was much less positive in an argument than post on Twitter, underlining that the immutability of the blockchain was completely compromised:
"A profound reorg is a rewriting of the blockchain, a rewriting of history." As such, it marks the complete failure of immutability.And immutability is the main claim of renown of ETC, this is technically a catastrophic failure. Let's see what the exchanges will do in response ".
Changes to the Ethereum work test
While the ETC blockchain tackles the most recent debacle, the Ethereum core developers (ETHs) have reached an attempt to implement a new PoW algorithm on January 4th.
The move aims to address the apparent division in terms of efficiency between the extraction of ASICs and GPUs on the Ethereum network.
ASIC mining was developed to efficiently extract cryptocurrencies using specific algorithms. Ethereum was originally designed to be resistant to the ASIC, although the ASIC chips were developed capable of running the ethash algorithm.
However, for Ethereum changes have been going on for some time. The main developers should make a more detailed call on the implementation of "ProgPoW" on January 18th.
All of this is in line with the final goal of moving entirely to a "stake test" (PoS) consensus system. The first main move to this eventuality is the hard gallows of Constantinople, which should also take place this month.
The hard fork will also include other Ethereum enhancement proposals (EIP) to simplify the transition from PoW to PoS.
As Ethereum goes forward, ETC developers will reflect on their next move. The smaller cryptocurrencies that use the PoW algorithms are more at risk of these types of attacks, but this does not mean that they will be targeted by attackers.
Donald McIntyre, a member of the ETC development team, wrote a short post on Medium, unpacking the attack and possible ways to follow for ETC.
"My personal opinion is that what happened is a meaningful stop, but I think ETC still has a unique positioning as a PoW + Turing-complete network with an active community with solid principles. a medium to long-term recovery is plausible or if the network, unless it grows significantly, is perpetually vulnerable, then unusable. "
Once the development team and the ETC community have taken stock of the damage, the way forward can start to be taken into consideration. It remains to be seen whether this includes a change in the consensus method.
[ad_2]
Source link
