Ethereum Devs Propose Deposit Contract Overhaul to Quantum-Proof Staking

In brief

A draft EIP submitted Monday would replace Ethereum’s validator deposit contract with one accepting variable-length keys, clearing the way for post-quantum credentials.
It adds an irreversible retirement mode that would permanently block new deposits signed with today’s BLS scheme.
The proposal is still a draft awaiting editor review, with contract addresses and activation timestamps undecided.

Ethereum developers have proposed rebuilding the contract that every validator passes through on the way into staking, in the first concrete move to prepare the network’s $100 billion-plus staking layer for post-quantum cryptography.

The draft proposal, submitted to the Ethereum Improvement Proposal repository on Monday, targets a constraint hiding in the existing contract: it hardcodes the dimensions of BLS12-381, fixing public keys at 48 bytes and signature metadata at 96. Post-quantum schemes need considerably more room, and the current contract has none to give.

The replacement accepts keys and credential metadata of up to 8,192 bytes each, and asks every deposit to declare which “credential scheme” it uses. Scheme zero means BLS. The proposal assigns no others, leaving a future EIP to define what a post-quantum validator key actually looks like.

The contract runs in three modes—disabled, BLS enabled, and BLS retired—and once a system call moves it to retirement, the authors write, no later call can re-enable BLS onboarding.

The proposal carries deposit data to the consensus layer and leaves the cryptography to be specified later. It would need a coordinated fork across both layers to take effect.

Not a “simple upgrade”

The pull request is labelled a draft awaiting review from the EIP editors, with its contract address, deployment code and both activation timestamps are marked as undecided.

One of its three authors, Thomas Coratger, spent the same day setting out how unsettled the underlying cryptography remains in a Twitter thread.

Is crypto prepared for the quantum threat?
Recently, legendary cryptographer @danboneh broke down the massive challenge of post-quantum (PQ) signatures for blockchains.
Let’s summarize the findings about hash-based signatures, SHRINCS, and the threshold problem. 🧵👇
— Thomas Coratger (@tcoratger) August 24, 2026

Summarising a talk by Stanford cryptographer Dan Boneh, he wrote that Bitcoin and Ethereum are both “heavily leaning” toward hash-based signatures, which rest only on assumptions the networks already trust. The stateless versions standardised by NIST run to roughly 8KB each, matching the ceiling the new contract sets, while the compact alternatives carry a counter that leaks the private key if a signer ever reuses it.

“Post-quantum cryptography isn’t a simple upgrade,” Coratger wrote.

The Ethereum Foundation assembled a team last year to plan the network’s post-quantum transition, while a May report from quantum security firm Project Eleven put the odds of a machine capable of breaking elliptic curve signatures at better than even by 2033, with 2030 possible.

More than 65% of all ETH sits in addresses whose public keys are already exposed onchain, according to that analysis.