Ethereum developers have proposed rebuilding the deposit contract used by every validator entering staking, in what the draft describes as the first concrete step toward preparing the network’s staking layer—worth more than $100 billion—for post-quantum cryptography.
The draft was submitted to the Ethereum Improvement Proposal repository on Monday. It targets a specific limitation in the current contract: BLS12-381 dimensions are hardcoded, fixing public keys at 48 bytes and signature metadata at 96 bytes. Post-quantum systems require far more space, and the existing contract does not provide it.
A larger container for validator credentials
The proposed replacement would accept keys and credential metadata of up to 8,192 bytes each. It also requires every deposit to specify which credential scheme it uses. Scheme 0 is assigned to BLS. No other schemes are defined in the draft, leaving a future EIP to spell out what a post-quantum validator key would actually look like.
The contract would run in three modes: disabled, BLS enabled, and BLS retired. According to the authors, once a system call moves the contract into the retired state, no later call can turn BLS onboarding back on.
The proposal passes deposit data through to the consensus layer while leaving the underlying cryptography to be defined later. For the change to take effect, Ethereum would need a coordinated fork across both the execution and consensus layers.
Draft status and open design questions
The pull request is still marked as a draft and awaits review by the EIP editors. Its contract address, deployment code, and both activation timestamps are all listed as undecided.
Thomas Coratger, one of the proposal’s three authors, used a Twitter thread the same day to argue that the cryptographic foundation remains unsettled.
Summarizing a talk by Stanford cryptographer Dan Boneh, Coratger wrote that both Bitcoin and Ethereum are “heavily leaning” toward hash-based signatures because those systems rely only on assumptions the networks already trust. The stateless variants standardized by NIST are roughly 8KB each, matching the cap introduced in the proposed contract. More compact alternatives, he said, include a counter that can leak the private key if a signer ever reuses it.
“Post-quantum cryptography isn’t a simple upgrade,” Coratger wrote.
Quantum risk timeline
The Ethereum Foundation assembled a team last year to plan the network’s transition to post-quantum security. A May report from quantum security firm Project Eleven estimated that the odds of a machine capable of breaking elliptic curve signatures are better than even by 2033, with 2030 also possible.
That same analysis said more than 65% of all ETH is held in addresses whose public keys are already exposed onchain.