Ethereum researchers submitted a draft proposal on Aug. 24 for a post-quantum-ready validator deposit contract that could eventually allow the network to replace its current BLS signature system.
Summary
- Ethereum researchers submitted a draft post-quantum deposit contract proposal for validator signature migrations this week.
- The design supports variable-length public keys, signature schemes and metadata without selecting a post-quantum algorithm yet.
- Scheme 0 would preserve current BLS deposits while later identifiers accommodate alternative cryptographic signature systems.
- An irreversible migration switch could eventually stop new BLS deposits after a staged transition period.
- The pull request remains a draft awaiting editor consensus, technical review, discussion and successful checks.
Kevaundray Wedderburn, Tom Wambsgans and Thomas Coratger authored the proposed core Ethereum Improvement Proposal. The draft remains an unmerged GitHub submission and has not been selected for a network upgrade.
Ethereum proposal prepares deposits for new signatures
Ethereum validators currently use BLS public keys and signatures with fixed lengths. The proposed contract instead accepts variable-length public keys, signatures and credential metadata.
Each deposit would contain a scheme identifier showing which cryptographic system the validator uses. Scheme 0 is reserved for the existing BLS format, preserving compatibility during an initial transition.
Future identifiers could represent post-quantum signature systems or other cryptographic schemes. The proposal does not select or implement a specific post-quantum algorithm.
The contract is “post-quantum-ready,” but it would not make Ethereum quantum-resistant on its own.
A separate consensus-layer change would still need to define how validators verify, aggregate and process signatures under each new scheme.
EIP-7685 would carry validator deposit requests
The design would replace the new contract’s legacy-style Merkle-tree mechanism with execution-layer requests. Those requests would move deposit information from Ethereum’s execution layer to its consensus layer.
The proposal relies on EIP-7685, which created a general request system for communication between the two layers. The framework adds a request commitment to execution block headers and lets the consensus layer process new request types.
Ethereum already uses the mechanism for validator operations. EIP-6110 supplies validator deposits to the consensus layer as EIP-7685 requests, while EIP-7002 supports execution-layer-triggered withdrawals. EIP-7251 uses the same framework for validator consolidations.
The new contract would extend this architecture to deposits containing flexible cryptographic data. Credential metadata could carry scheme-specific information without requiring every signature system to use the same fixed structure.
An irreversible switch could retire BLS deposits
The proposal includes a staged migration mechanism. Developers could initially deploy the contract with BLS deposits enabled while allowing additional signature schemes to enter later.
A subsequent protocol decision could permanently disable new Scheme 0 deposits. Once activated, the BLS retirement mode could not be reversed under the proposed design.
Existing BLS validators would not automatically disappear when the switch was activated. Separate rules would be needed to address existing validator keys, exits, credential changes and migration into a post-quantum system.
The authors are also waiting for feedback on how the design should interact with existing validator proposals, including EIP-7002, EIP-7251 and EIP-8282. Wedderburn said the subject had been raised during an All Core Developers Execution meeting.
Ethereum’s broader roadmap already treats quantum resistance as a central long-term priority. Proposed changes include replacing BLS signatures, KZG commitments and ECDSA with alternatives designed to resist future quantum attacks.
The draft still faces several review stages
The pull request carries draft and core-proposal labels. It was also waiting for editor consensus, formal review and successful automated checks when examined.
An editor suggested assigning EIP-8394 as its sequential number and requested a separate Ethereum Magicians discussion. That number was not yet shown as an accepted, published EIP on the canonical EIP website.
Ethereum’s EIP repository states that documents not published on the official EIP website should be treated as working papers. Even publication as a draft would not mean the network had approved implementation.
The proposal would need technical discussion, specification work, security analysis, client implementations and testing. Core developers would then have to select it for a future hard fork before it could affect Ethereum mainnet.
No target fork, testnet activation or mainnet deadline has been announced. There was also no verified ETH market movement attributable specifically to the draft.
The contract addresses only validator deposits. Ethereum’s broader post-quantum transition must also cover account signatures, data commitments and zero-knowledge systems, as earlier analysis of Ethereum’s migration plan explained.
