Ethereum Developers Successfully Freeze Difficulty Bomb Countdown

The Gray Glacier hard fork that was designed to delay the difficulty bomb went live on Ethereum without a hitch, according to the network's core developers including Ethereum Foundation's Tim Beiko, when it was implemented on Thursday.

The Sepolia testnet is also set to run through the next few days of its Merge trial and is the last one to go through this trial before the official Merge.

The Gray Glacier hard fork was initiated on block number 15050000 at roughly 6:54 am ET, June 30. The hard fork will now delay the difficulty bomb by roughly 700,000 blocks or 100 days, giving developers until mid-October to finish the much-anticipated Merge.

Later that day, Ethereum Foundation community manager Tim Beiko quickly noted on Twitter that at 20 blocks past the fork, all monitored notes were in sync, saying:

“20 blocks past the fork and it's looking good: all monitored nodes except @OpenEthereumOrg, which doesn't support the fork, are in sync. No blocks on the old chain so far!”

Nethermind, an Ethereum developer, confirmed on Twitter that the hard fork was successful and that the difficulty bomb had been delayed.

The difficulty bomb is a mechanism that will gradually reduce the incentive for miners to mine Ethereum using Proof-of-Work (PoW) as the network approaches its merger with the PoS-based Beacon Chain.

This can be done by increasing the difficulty level of puzzles in the PoW mining algorithm, which will result in longer block times and fewer ETH rewards. The mechanism would also make it more complicated for developers to complete the Merge as its block-creation slows down gradually.

The difficulty bomb was pushed back, as it would have slowed down the creation of new blocks to a point that it would be extremely difficult to introduce new network upgrades.

The difficulty bomb has been pushed back on multiple occasions due to the Merge experiencing numerous delays over recent years. The previous Arrow Glacier delay occurred in December 2021 and postponed the bomb until the middle of 2022.

Sepolia's acquisition of X&T was announced in late 2018.

On June 30, the Ethereum Foundation shared a post on Twitter from Sepolia announcing that the testnet will do a dress rehearsal of the Merge over the next few days, marking the second of three public testnets to do so.

“After years of work to bring proof-of-stake to Ethereum, we are now well into the final testing stage: testnet deployments!”

"Since Ropsten has already been switched to proof-of-stake and shadow forks are still occurring regularly, Sepolia is ready for the Merge," the post said.

On the Ethereum Foundation website, it vaguely estimates that the official Merge will go through during Q3/Q4 2019, and the latest post also says that “the date for the Ethereum mainnet proof-of-stake transition has not been set. Any source claiming otherwise is likely to be a scam. Updates will be posted on this blog.”