EIP3238 - Difficulty Bomb Delay to Q2/2022

# Simple Summary

Delays the difficulty bomb so 30 second blocks won't happen until around Q2/2022.

# Abstract

Starting with 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 eleven million blocks later than the actual block number.

# Motivation

Even after the Ethereum 2.0 mainnet launch, Ethash proof-of-work mining on the legacy chain should be feasible. It should allow miners sealing new blocks every 13~15 seconds on average for another ten months and allow both Ethereum 1.x and Ethereum 2.0 developers to conclude the merge.

# Specification

# Relax Difficulty with Fake Block Number

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 - 11_000_000) if block.number >= FORK_BLOCK_NUMBER else block.number

# Rationale

This will delay the ice age by another ~26 million seconds (approximately ~9.89 months), so the chain would be back at ~30 second block times in Q2/2022. Hopefully, by then the Eth1-to-Eth2 merge will be concluded and the ice age fulfilled its task.

# Backwards Compatibility

This EIP is not forward compatible and introduces backwards incompatibilities in the difficulty calculation. Therefore, it should be included in a scheduled hardfork at a certain block number. It's suggested to consider this EIP either with or shortly after the Berlin hard-fork but not later than July 2021.

Alternatively, in order to maintain stability of the system, a it can be considered to activate this EIP along with EIP-1559 fee market changes in a bundle. With the delay of the ice age, there is a desire to no further increase inflation and rather incentivize users to participate in proof-of-stake consensus instead.

# Security Considerations

There are no known security issues with this proposal.