Ethereum Prepares for Post-Quantum Future with Deposit Contract Overhaul

Ethereum developers are proposing changes to the deposit contract that validators use when staking. The new contract would accept variable-length keys, paving the way for post-quantum credentials.

The current contract hardcodes the dimensions of BLS12-381, limiting public keys to 48 bytes and signature metadata to 96. Post-quantum schemes require more space, which this proposal addresses by allowing keys and credential metadata up to 8,192 bytes each.

The replacement contract would run in three modes: disabled, BLS enabled, and BLS retired. Once a system call moves it to retirement, no later call can re-enable BLS onboarding.