Understanding the ETC Thanos Hard Fork Upgrade in One Article

At 03:48 on November 29, 2020, ETC (Ethereum Classic) finally ushered in a major change after struggling through months of "dark moments" - the Thanos hard fork upgrade.

So, what exactly is the Thanos hard fork? What prompted ETC to conduct this hard fork? What impact will the Thanos hard fork have on the ETC ecosystem? Can the Thanos hard fork, which is highly expected by ETC Labs and the ETC core development team, lead ETC out of the quagmire and climb to a higher peak?

This article will provide a comprehensive analysis of ETC's Thanos hard fork. Some of the opinions in this article are just one person's opinions, and readers should refer to and adopt them with caution.

01 Thanos Hard Fork

ETC upgraded its nodes at block height 11,700,000, which was 03:48 on November 29, 2020. The upgraded nodes completed the code implementation in the ECIP-1099 proposal: extending the length of the epoch .

Ethereum Classic (ETC) used to have an epoch of 30,000 blocks , just like Ethereum (ETH). Every time an epoch is updated, the size of the DAG file will increase. After the upgrade, the epoch length of Ethereum Classic will be doubled, with an epoch of 60,000 blocks .

The DAG file in the ETH and ETC networks is a data packet based on the Ethash algorithm. In ETH and ETC mining, the DAG file needs to be located in the video memory of the mining device to assist in mining. Its size will increase with the increase of epoch. Before the Thanos hard fork, the size of ETC's DAG file has reached 4GB, which means that before the Thanos hard fork, graphics cards with 4GB video memory cannot mine ETC.

After the upgrade, the epoch length of ETC doubled, and the size of the DAG file was greatly reduced from the original 4GB to 2.47GB . At the same time, by changing the calculation method of epoch, ETC's mining algorithm was also upgraded based on the Ethash algorithm to become the Etchash algorithm , initially breaking away from the ETH algorithm family.

This is ETC’s Thanos hard fork.

02 Reasons for Thanos Hard Fork

Reason 1: Ending ETH’s dominance of computing power and getting rid of the dilemma of computing power attacks

As a forked currency of ETH, ETC has been under the protection of the big tree of ETH, but has also been shrouded in the shadow of ETH.

To some extent, before the Thanos hard fork, ETC and ETH were a pair of clone brothers. They used the same mining algorithm and almost identical codes. All technological innovations on the ETH network could basically be implemented on the ETC network. ETC enjoyed the huge technological dividends of ETH.

In addition, since ETC mining and ETH mining use the same mining algorithm, it is very easy to switch between them. Only a small number of the millions of mining machines involved in ETH mining around the world need to flow into ETC mining to form a strong scale effect.

However, due to its high dependence on ETH mining, ETC's mining ecology and network security are extremely fragile : 1% of ETH computing power can launch a computing power attack on the ETC network, or even a 51% attack. 1% of ETH computing power can be purchased from Nicehash by the second, at a very low cost; it can also be obtained by paying to rent from large miners, because there are many large ETH miners with more than 1% computing power. This is indeed the case:

• In January 2019, the ETC network suffered multiple consecutive 51% computing power attacks , and mainstream exchanges such as Coinbase, Binance, and Gate.io suffered heavy losses;

• On August 1, 2020, the ETC network suffered a 51% computing power attack. The attacker reorganized the ETC block and double-spent more than 800,000 ETCs, directly causing the victim to suffer a loss of $5.6 million. At the same time, the miners who participated in ETC mining at the time also suffered tens of thousands of dollars in economic losses. It is reported that the cost of the attacker to purchase Ethash computing power from Nicehash to attack the ETC network was 17.5 BTC, about $200,000.

• On August 5, 2020, the ETC network suffered another 51% computing power attack , and more than 4,000 ETC blocks were reorganized;

• On August 29, 2020, the ETC network once again suffered a 51% computing power attack . This time, as many as 7,000 ETC blocks were reorganized and related transactions were affected.

The continuous attacks caused ETC’s “dark moment” and exposed major security risks in the ETC network. Various exchanges began to extend the time it takes to deposit ETC (from half an hour to more than 2 weeks), and many exchanges even directly removed ETC from their shelves.

Miners also suffered a lot of losses in many of these attacks. The extremely long time to receive funds has dampened the enthusiasm of other miners to a certain extent. As a result, there is a situation where even though the mining income of ETC far exceeds that of ETH, there are still not enough miners participating in ETC mining. This in turn makes the security of the ETC network more vulnerable.

Figure 1. Changes in the computing power of the entire network after the ETC network suffered a computing power attack in August

Therefore, ETC must change its algorithm and cut off from ETH mining to prevent attackers from attacking the ETC network by acquiring ETH computing power at low cost .

Reason 2: Attract computing power abandoned by ETH and strengthen the ETC ecosystem

The mining algorithm used by ETH and ETC increases the mining machine's video memory requirements by continuously increasing the size of DAG files, thereby enhancing its anti-ASIC capabilities.

ETH's DAG file will reach 4GB in December 2020, when all graphics cards with 4GB or less of video memory will be eliminated from ETH mining . This means that AMD 470/480/570/580 4GB video memory graphics cards, one of the main forces in ETH mining, will withdraw from the ETH mining market in December.

These graphics cards were once widely loved by miners for their high quality, low price and high cost performance, and accounted for a very high proportion of ETH mining equipment. When the DAG file of ETH reaches 4GB, the computing power of a large number of 4GB graphics cards will be withdrawn, and the ETH network is bound to be greatly shaken. However, the ETH team has been trying to get rid of the influence of mining and promote PoS consensus. Therefore, without harming network security, it is extremely consistent with the official demands of ETH to significantly reduce the computing power of the entire network. They will not take any measures to save the 4GB memory graphics cards .

Miners who hold 4GB graphics cards were once in a panic. Some miners who bought second-hand 4GB graphics card mining machines may have just been happy about the ultra-low price of the mining machine, but then they were dominated by the fear of having no mines to mine. If there is a currency that can support mining with 4GB graphics card mining machines at this time, a large number of miners will definitely flock to it.

Figure 2 A large number of 3GB and 4GB graphics card mining machines will flood into the ETC mining market

ETC chose to carry out this Thanos upgrade at this time, which just solved the urgent needs of miners with 4GB video memory graphics cards. By accepting the computing power eliminated by ETH, on the one hand, it will gather miners and expand the community influence; on the other hand, these graphics cards that have to switch to the ETC network will increase the computing power of the entire ETC network to an unprecedented level, and the security of its network will also be greatly improved .

03 Impact of Thanos Hard Fork

The Thanos hard fork mainly upgrades and changes the ETC mining field, and the main impacts are as follows.

• The size of ETC's DAG file has been reduced to less than 3GB, and graphics cards with 3GB and 4GB video memory can participate in ETC mining again . On the first day after the Thanos hard fork, the ETC network's computing power increased from 4.15Th/s to 6Th/s.

Figure 3 After the Thanos hard fork, the ETC network computing power has increased to a certain extent

• The ETC algorithm has been upgraded to Etchash. ETC and ETH no longer use the same algorithm. Graphics card miners need to update their mining software to support the new ETC algorithm in order to mine ETC.

• The Ethash algorithm computing power on Nicehash will no longer support ETC mining. Maybe Nicehash will support the buying and selling of computing power of the new ETC algorithm in the future, but at that time it will be difficult for attackers to buy enough ETC computing power on Nicehash to attack the ETC network (because the computing power sold by almost all currencies on Nicehash only accounts for a very low share of its total computing power, and it is difficult to pose a threat to the original currency network).

• The dream of E3, A10 (4GB video memory) and other ASIC mining machines with low video memory to continue mining ETC after waiting for upgrade has been shattered: E3 and A10 mining machines cannot mine ETC for the time being . Now it seems that they only have one way to save themselves, which is to upgrade the video memory. It is estimated that the company that provides A10 video memory upgrade services will become popular again.

The Thanos hard fork is the answer given by the ETC team to the problem of repeated computing power attacks in August: by changing the algorithm and cutting off from ETH mining, it prevents attackers from using low-cost ETH computing power to attack ETC, thereby improving network security; by reducing the demand for DAG files, it fully absorbs the computing power eliminated by ETH, and even activates the 3GB video memory graphics card that has been eliminated for nearly a year, greatly improving the computing power of the ETC network and enhancing the vitality of the ETC ecosystem.

Its design concept and timing are quite ingenious and took a lot of thought. The upgrade has just been completed. Except that the ETC network computing power has been improved after the Thanos hard fork upgrade, there is no other feedback from the market for the time being. Whether the Thanos hard fork can make ETC reborn, regain new life, or even move to a higher level, it will take time to verify, so let us wait and see. Finally, readers are welcome to search and follow the official account "mining_club". The author will share consultations on digital currency mining in the official account from time to time.