Ethereum Researchers Propose Quantum Security for 42 Million ETH Staking
Ethereum researchers have proposed the first technical step to protect the staking infrastructure, which covers approximately 42.4 million ETH, against future quantum computer attacks.
The early draft reported by CoinDesk aims to modify the deposit contract structure that allows users to become validators by locking ETH. The proposal, which is currently under review, paves the way for this contract—the entry point for staking on Ethereum—to accept different signature types in the future.
Approximately $104 billion worth of ETH is currently staked on Ethereum. The current system fixes the size of BLS keys used by validators within the contract. Consequently, even if developers agree on a new and more quantum-resistant signature method, the contract cannot directly accept it.
Tagged signature transition proposed for Ethereum staking
The draft proposes that each staking record carry a tag indicating which cryptographic method it uses. While the current BLS system continues to work with the first tag, different signature systems to be developed in the future can also be added to the same contract.
If the proposal is accepted, new BLS registrations could be halted later. However, existing validators using BLS keys will not be removed from the system; rather, new validators may be prevented from joining the network with these keys in the future. A separate update will also be required to determine how validators will verify the new signatures.
BLS signatures lower Ethereum’s transaction verification costs by combining numerous validator signatures into a single signature. However, the possibility of powerful quantum computers breaking this structure to produce fake validator signatures has accelerated long-term security plans. While a study published in March revealed five possible attack vectors, the Ethereum Foundation is working toward a 2029 target for core changes. This process is moving forward as part of an early draft prepared for future threats, not as a reaction to a realized quantum attack.