Ethereum's EIP-7685 deposit contract targets post-quantum staking security

Ethereum researchers want to swap the network's BLS signature system for a post-quantum-ready deposit contract that can support flexible cryptographic schemes.

Ethereum researchers submitted a draft proposal on Aug. 24 for a post-quantum-ready validator deposit contract that would allow the network to eventually retire its current BLS signature system, according to a GitHub pull request.

"The subject was raised during an All Core Developers Execution meeting," Kevaundray Wedderburn, one of the proposal's three authors alongside Tom Wambsgans and Thomas Coratger, said, noting the design still needs feedback on how it interacts with existing validator proposals including EIP-7002, EIP-7251 and EIP-8282.

The proposed contract accepts variable-length public keys, signatures and credential metadata, with each deposit carrying 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. The design replaces the current Merkle-tree mechanism with execution-layer requests under EIP-7685, which created a general request system for communication between Ethereum's execution and consensus layers. EIP-6110 already supplies validator deposits to the consensus layer as EIP-7685 requests, while EIP-7002 supports execution-layer-triggered withdrawals.

The proposal includes a staged migration mechanism that could permanently disable new Scheme 0 deposits once activated — an irreversible switch. No target fork, testnet activation or mainnet deadline has been announced. Ethereum's broader roadmap already treats quantum resistance as a central long-term priority, with proposed changes covering BLS signatures, KZG commitments and ECDSA.

Post-quantum standards set the stage

The proposal arrives as the US National Institute of Standards and Technology finalized its first post-quantum cryptography standards in August 2024, formalizing two approaches: a lattice-based scheme called ML-DSA and a hash-based scheme called SLH-DSA built on Sphincs+. Ledger CTO Charles Guillemet has noted that blockchain ecosystems including Bitcoin and Ethereum have gravitated toward the hash-based route because it relies on cryptographic primitives like SHA-256 and SHAKE that these communities have trusted since their earliest days.

Ethereum researchers have separately been exploring optimized Sphincs+ variants designed to make verification more manageable inside the Ethereum Virtual Machine — a parallel effort showing the deposit contract proposal is part of a wider push to harden the network's cryptographic base.

Market context

ETH traded near $2,480 as of Aug. 25, with BlackRock's Ethereum ETF adding $90.9 million in inflows, according to available data. The proposal does not select or implement a specific post-quantum algorithm — it only creates the infrastructure to support future schemes. A separate consensus-layer change would still need to define how validators verify, aggregate and process signatures under each new scheme.

The contract addresses only validator deposits. Ethereum's broader post-quantum transition must also cover account signatures, data commitments and zero-knowledge systems. The draft carries draft and core-proposal labels and was waiting for editor consensus, formal review and successful automated checks when examined. An editor suggested assigning EIP-8394 as its sequential number.

This article is for informational purposes only and does not constitute investment advice.