Table of Contents
Delays the difficulty bomb to show effect the first week of December 2021.
FORK_BLOCK_NUMBER the client will calculate the difficulty based on a fake block number suggesting to the client that the difficulty bomb is adjusting 9,700,000 blocks later than the actual block number.
Targeting for the Shanghai upgrade and/or the Merge to occur before December 2021. Either the bomb can be readjusted at that time, or removed all together.
For the purposes of
calc_difficulty, simply replace the use of
block.number, as used in the exponential ice age component, with the formula:
fake_block_number = max(0, block.number - 9_700_000) if block.number >= FORK_BLOCK_NUMBER else block.number
The following script predicts a .1 second delay to blocktime the first week of december and a 1 second delay by the end of the month. This gives reason to address because the effect will be seen, but not so much urgency we don’t have space to work around if needed.
def predict_diff_bomb_effect(current_blknum, current_difficulty, block_adjustment, months): ''' Predicts the effect on block time (as a ratio) in a specified amount of months in the future. Vars used in last prediction: current_blknum = 12382958 current_difficulty = 7393633000000000 block adjustment = 9700000 months = 6 ''' blocks_per_month = (86400 * 30) // 13.3 future_blknum = current_blknum + blocks_per_month * months diff_adjustment = 2 ** ((future_blknum - block_adjustment) // 100000 - 2) diff_adjust_coeff = diff_adjustment / current_difficulty * 2048 return diff_adjust_coeff diff_adjust_coeff = predict_diff_bomb_effect(12382958,7393633000000000,9700000,6)
No known backward compatibility issues.
Misjudging the effects of the difficulty can mean longer blocktimes than anticipated until a hardfork is released. Wild shifts in difficulty can affect this number severely. Also, gradual changes in blocktimes due to longer-term adjustments in difficulty can affect the timing of difficulty bomb epochs. This affects the usability of the network but unlikely to have security ramifications.
Copyright and related rights waived via CC0.
Please cite this document as:
James Hancock, "EIP-3554: Difficulty Bomb Delay to December 2021," Ethereum Improvement Proposals, no. 3554, May 2021. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-3554.