The Core Devs and the Security Community recently announced that the Constantinople Hard Fork was postponed until February 27 since researchers from ChainSecurity found out that one of the implementations would have the side effect of enabling reentrancy attacks (similar the one suffered by The DAO).
A significant number of nodes had already been updated and they have since had to revert to the previous version to avoid being forked out of consensus. Fortunately, the block 7,080,000 has already passed without incident, however, other issues lie ahead for Ethereum such as the ‘difficulty bomb’ which has come into effect.
When the Byzantium Hard Fork (Block 4,370,000, Oct 16, 2017) delayed the difficulty bomb, it stated that after 3 million blocks (block 7,370,000) block times would be similar to those prior to Metropolis phase 1 (Byzantium Hard Fork). When the effects were felt for the first time, average block times increased to almost 30 seconds (it should be 14 seconds).
When you forget to hit the Snooze button on your difficulty bomb https://t.co/wxDJAODwAM— Hasu (@hasufl) January 16, 2019
Data from etherscan shows some growth in the average blocktime:
So we are already seeing some effects of the difficulty bomb. The difficulty bomb was designed to exponentially increase mining difficulty until it is impossible to mine Ethereum and that’s when we supposedly would see Ethereum transition to a fully proof of stake network.
What the difficulty bomb does is calculate the difficulty necessary for maintaining the block time and, at press time, add 2^38 to the difficulty. Níckolas Goline, Blockchain developer and teacher at Blockchain Academy, calculated that in block 7.100.002 - which is expected in under 2 days based on current difficulty and hasrate trends - we’ll have average block times nearing 30 seconds. That would have detrimental impacts on many Dapps.
Credits for Níckolas Goline
However, Afri Schoedon, who is the author of both EIP649 and EIP1234 that delayed the difficulty bomb in Byzantium and would do so in Constantinople respectively, said that the situation was nothing to be concerned about. A recent tweet from Péter Szilágyi, team lead at Ethereum, stated that Ethereum developers have already rescheduled the fork for Feb 27.
Seems we're going with block 7.28M for the #Ethereum Constantinople refork scheduled for the 27th of February! Will be a single fork on mainnet and a post-Constantinople-fixup fork on the testnets to get them back in line feature wise with the main network.— Péter Szilágyi (@peter_szilagyi) January 18, 2019
But, if Níckolas’ calculations are right and, the current difficulty and hashrate trends remain intact we’ll see block times of more than 60 seconds by February 27. Which could cause a variety of negative impacts for the DApp ecosystem.