Ethereum’s difficulty bomb has not actually been triggered, but it has taken effect

It has been nearly a month since the Ethereum Constantinople hard fork was postponed, and it is getting closer to the expected February 27th. However, what users are most concerned about is the EIP-1234 upgrade of this hard fork. The reduction in ETH production and the postponement of the difficulty bomb brought by it are regarded as the most influential updates before Ethereum PoS, and are closely related to the value of ETH. Among them, the topic of whether the difficulty bomb will be activated, which is of great concern to Ethereum users and miners, has not been determined in the community debate until February 10, when the Ethereum block time suddenly increased to 20 seconds.

The Ethereum difficulty bomb is a layer of insurance set up to ensure a smooth transition of Ethereum to the PoS consensus mechanism. After the difficulty bomb is activated, the difficulty of Ethereum blocks will increase exponentially, and PoW mining will become unprofitable. This is to ensure that Ethereum miners can abandon the current PoW mining and switch to PoS, and to ensure that miners' behavior will not cause forks on the original PoW chain.

However, the slow progress of Ethereum PoS has made it impossible to effectively implement the originally planned evolutionary path, and the difficulty bomb cannot play a corresponding role. However, because the code launch time has been set, the Ethereum difficulty bomb will still be launched as scheduled. For example, the sharp increase in difficulty before the Byzantium hard fork on October 16, 2017 was the masterpiece of the difficulty bomb.

It has been nearly 1 year and 4 months since the Byzantium hard fork. The one-year extension of the difficulty bomb brought by the EIP 649 upgrade has far exceeded the deadline. The Constantinople hard fork originally scheduled for the end of January 2018 has also been postponed due to security issues. We have to worry about whether the difficulty bomb has been activated.

Mars Finance (WeChat: hxcj24h) found that in fact, many reports oversimplified the description of Byzantium EIP 649. The report mentioned that it postponed the difficulty bomb for 1 year. In fact, EIP 649 postponed the difficulty bomb from 4370000 by 3 million blocks, and will be launched at a block height of 7370000, which is actually later than the original 7080000 block height of the Constantinople hard fork, and the postponed 7280000 block height.

(Difficulty bomb postponed for 3,000,000 blocks)

So, strictly speaking, the Ethereum difficulty bomb has not been activated, and the code-based difficulty bomb cannot be activated.

But from another perspective, the difficulty bomb has indeed been "activated" and has begun to affect the Ethereum network. The impact of the difficulty bomb on the Ethereum network is mainly reflected in the block resolution time. The effect of the difficulty bomb can be clearly seen from the Ethereum block time chart. Since Ethereum crossed the 7100000 block on January 3, its block time has quietly risen by one level. Mars Finance (WeChat: hxcj24h) learned that even Ethereum core developer Afri Schoedon said that this has hardly attracted any attention.

Ethereum's current block time is irregular compared to before the Byzantium hard fork. This is because at the end of 2017, the number of Ethereum users increased dramatically, and the network computing power increased significantly, which shortened the block time that was affected by the difficulty bomb. However, at the beginning of 2019, due to the sharp drop in ETH prices and the shutdown of Ethereum miners, the difficulty of the Ethereum network fluctuated greatly, resulting in irregular block time on the Ethereum network, but it does have a trend of step-like exponential growth. So the difficulty bomb has indeed been "activated", and just yesterday, the Ethereum block time has increased to 20 seconds.

(Average Ethereum block time)

Why did the difficulty bomb that was supposed to be launched at block height 7370000 explode in advance? Mars Finance (WeChat: hxcj24h) found that in fact, Ethereum developers have explained the rationality of the EIP 649 description file. They said that the difficulty bomb implemented after delaying 3 million blocks is equivalent to a delay of 1.4 years, and caused the block time to return to 30 seconds at the end of 2018. That is, Ethereum developers use 30 seconds as the base point for the block time, so the current increase from 15 seconds to the block time is within their expectations.

(EIP-649 rationale explanation)

However, the Ethereum Constantinople hard fork has had a rough fate. The test network launched in October 2018 ended in failure. The hard fork originally scheduled for the end of January on the main network was postponed due to the discovery of a smart contract vulnerability, and the Ethereum node upgrade preparation completion rate was very low at the time. As of press time, according to ethernodes statistics, only 10.7% of clients currently support the Ethereum Constantinople hard fork. Whether the postponed hard fork can be successfully implemented is still an unknown. If the upgrade fails again, the Ethereum network will inevitably enter an ice age triggered by the difficulty bomb, which will lead to an exponential increase in block time, a sharp drop in the Ethereum PoW network's block output, soaring gas fees, severe congestion and other negative issues.