Ethereum developers have proposed a new version of the deposit contract designed for signatures resistant to quantum attacks.
Currently, a validator connects to the network through a smart contract that accepts deposits and operates solely with BLS cryptography. The draft authors aim to make this mechanism independent of a specific scheme, allowing the blockchain to transition to other algorithms, including post-quantum, without overhauling the infrastructure.
To achieve this, a flexible format is proposed: public keys and additional metadata are accepted as variable-length fields, and the cryptographic scheme used is identified by a separate numerical code. The current BLS standard is assigned the identifier Scheme 0.
The document does not specify a particular post-quantum implementation—the initiative merely lays the groundwork for its future adoption.
Developers also propose changing the handling of deposits. Instead of the currently used Merkle tree, data is planned to be transmitted to the consensus layer via execution requests through the EIP-7685 mechanism.
The draft provides for the possibility of gradually phasing out BLS: support for new deposits with this scheme can be activated for a transitional period and then permanently disabled.
Post-Quantum Account Protection in Monad
Developers of the EVM-compatible protocol Monad have proposed a similar model at the account level. Initiative authors Kushal Babel and Jan Camenisch aim to separate the permanent wallet address from the data users use to verify their control over it.
A new MIP has been published: Flexible and Upgradeable Account Authentication
Accounts can change their keys without changing their address
This lets accounts upgrade to quantum-resistant schemeshttps://t.co/Ajhnr3zwST
— Monad (@monad) August 24, 2026
In the current model, losing a private key means losing access to funds. Changing the security scheme requires creating a new address and transferring all assets to it.
In the proposed Monad system, a single address can sequentially use different authorization methods: adding, changing, or deleting keys, as well as connecting multiple signers and post-quantum algorithms.
The mechanism provides for access configuration and recovery. For example, a regular key remains primary, but two pre-designated trusted participants can jointly establish a new one if the owner loses the old one. Similarly, an account can be converted into a multisig without creating a new address.
This will also allow for the gradual replacement of current cryptography with quantum-resistant alternatives without mass token transfers between wallets.
The Monad proposal is in its early stages. According to Babel and Camenisch, the published version outlines the general architecture, and a full technical specification is yet to be prepared. If the mechanism is adopted, existing accounts will continue to operate unchanged.
In June, Kohaku project leader at the Ethereum Foundation Nicolas Consigny introduced a concept for post-quantum account protection without a hard fork.
