Ethereum Foundation contributors advanced the network's post-quantum readiness efforts on August 24 by presenting a draft plan to integrate quantum-safe keys into the contract validators use to join the network. If finalized, the proposal would initiate a process to rebuild and permanently switch off the network's current signature scheme.
The push to implement post-quantum code on the Ethereum mainnet follows cryptographic developments, including a March 2026 Google Quantum AI document that reduced the estimated cost of breaking Ethereum's 256-bit elliptic curve cryptography. While quantum computers capable of this feat do not currently exist, the National Institute of Standards and Technology (NIST) plans to deprecate ECDSA by 2030 and disallow it by 2035.
Proposed Contract Changes and BLS Retirement
The draft proposal was filed in the ethereum/EIPs repository by Kevaundray Wedderburn, with Thomas Coratger and Tom Wambsgans listed as co-authors. It outlines a validator deposit contract featuring variable length and a mode to irreversibly retire the Boneh-Lynn-Shacham (BLS) signature scheme.
Ethereum currently uses BLS signatures to combine hundreds of thousands of signatures into one for efficient consensus. However, this mathematical scheme can be solved by a quantum computer running Shor’s algorithm. To address this, the Foundation proposes using leanXMSS, a hash-based scheme that replaces 96-byte BLS signatures with nearly 3,000 bytes. The length-flexible contract and retirement switch are designed to accommodate these larger keys.
Roadmap and Timeline
The proposal is not yet ready for a vote. The author noted that the draft is unfinished and includes boilerplate covering EIP-7685 mechanics, while still requiring integration with existing validator EIPs 7251, 7002, and 8282.
Vitalik Buterin outlined a February 2026 roadmap focusing on four post-quantum readiness areas: validator BLS signatures including deposit contracts, KZG commitments behind data availability, ECDSA signatures guarding ordinary accounts, and zero-knowledge proof systems used by rollups. Additionally, EIP-8141 is under consideration for the Hegotá upgrade to handle account-level protection via native account abstraction.
The Ethereum Foundation established a dedicated post-quantum team in January 2026 and introduced initiatives such as the $1 million Poseidon Prize. Core L1 quantum upgrades are currently targeted for around 2029, though this planning goal remains subject to change. The draft currently awaits further editor review and a placeholder number reassignment to 8394 before advancing.
