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

The draft proposal, submitted to the Ethereum Improvement Proposal repository on Monday, targets a limitation built into the current contract: it hardcodes the dimensions of BLS12-381, fixing public keys at 48 bytes and signature metadata at 96 bytes. Post-quantum schemes require significantly more space, and the existing contract does not have it.

The replacement contract would accept keys and credential metadata of up to 8,192 bytes each, and would require each deposit to declare which "credential scheme" it uses. Scheme zero would indicate BLS. The proposal does not assign any other scheme values, leaving it to a future EIP to define what a post-quantum validator key should look like.

The contract would operate in three modes: disabled, BLS enabled, and BLS retired. Once a system call moves it into retirement, the authors say no later call can restore BLS onboarding.

The proposal would carry deposit data to the consensus layer and leave the cryptography to be specified later, underscoring that the staking plumbing can be redesigned before the new signature system is finalized. It would require a coordinated fork across both layers to take effect, making the change a network-wide coordination issue rather than a contract-only update.

Not a “simple upgrade”

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

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

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

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

Summarizing a talk by Stanford cryptographer Dan Boneh, Coratger wrote that Bitcoin and Ethereum are both “heavily leaning” toward hash-based signatures, which rely only on assumptions the networks already trust. The stateless versions standardized by NIST are roughly 8 KB each, matching the ceiling set by the new contract, while the more compact alternatives use a counter that can leak 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. A May report from quantum security firm Project Eleven said the odds of a machine capable of breaking elliptic curve signatures were better than even by 2033, with 2030 possible. According to that analysis, more than 65% of all ETH sits in addresses whose public keys are already exposed onchain.