Nicolas Consigny, the Ethereum Foundation’s Kohaku project lead, proposed a new method on Saturday to protect Ethereum accounts against quantum computing threats for as little as $0.07 per transaction. The proposal, detailed in a research paper shared on X and Ethresear.
ch, introduces “SPHINCS-,” an adapted version of the SPHINCS+ post-quantum signature standard that allows individual users to opt into higher security without requiring a network-wide hard fork.
The move comes as developers and researchers race to address the long-term risk posed to the Elliptic Curve Digital Signature Algorithm (ECDSA), which currently secures almost all digital assets. Nicolas Consigny noted that this approach leverages the ERC-4337 smart account standard to implement post-quantum protections at the account level.
This flexibility allows proactive users to migrate to smart contract wallets and secure their holdings against future cryptographic breakthroughs without waiting for a protocol-level change.
While the threat of a functional quantum computer capable of breaking modern encryption remains years away, the sheer volume of capital at risk has forced the issue to the forefront of development. By offering a low-cost, voluntary upgrade path, the Kohaku lead’s proposal provides a practical bridge for the network as research continues into more permanent, system-wide cryptographic upgrades.
Lowering the cost of quantum resistance on Ethereum
The primary barrier to implementing post-quantum signatures has historically been the massive amount of computational power and data storage required. Standard quantum-resistant signatures are heavy and expensive to verify on-chain. Nicolas Consigny’s SPHINCS- proposal attempts to thin out these requirements, bringing the cost down to a level that regular users might actually pay.
Current estimates suggest that a quantum-resistant signature under this scheme would consume approximately 200,000 gas. While this is significantly higher than the 3,000 gas traditionally consumed by standard ECDSA signatures, it is vastly more efficient than other high-security alternatives. For context, many Zero-Knowledge (ZK) proofs can consume up to 10 million gas, making them prohibitively expensive for routine account actions.
At current network rates, this translates to a cost of roughly seven cents per action. It’s a price point that makes security accessible, especially considering that Ether enters rare accumulation phase as markets cool, and long-term holders are looking for ways to park their assets indefinitely. However, actual costs will naturally fluctuate based on network congestion, potentially rising during periods of high demand.
Utilizing the SPHINCS- adapted signature standard
The SPHINCS- scheme is based on SPHINCS+, a standard developed by the US National Institute of Standards and Technology (NIST). NIST recently finalized SPHINCS+ as a primary standard for digital signatures in a post-quantum world. Kohaku’s adaptation specifically optimizes the signature for the Ethereum Virtual Machine (EVM) environment.
By focusing on efficiency, the team aims to provide a “signature-as-an-option” model. Users would not be forced to change how they interact with the blockchain, but those with high-value portfolios or long-term “set and forget” storage needs could choose to pay the premium for peace of mind. This opt-in nature prevents the entire network from slowing down under the weight of more complex cryptographic math.
Quantum risks facing Bitcoin and major blockchains
The discussion around quantum-proofing is not unique to Ethereum. Many industry analysts have raised alarms about the vulnerability of older blockchains, particularly Bitcoin, which lacks the smart-contract flexibility to easily pivot to new signature types. Estimates on the “quantum-at-risk” supply vary wildly among research firms.
Chaincode Labs recently estimated that up to 50% of the total Bitcoin supply, worth roughly $700 billion, is vulnerable to quantum attacks because it sits in “p2pkh” addresses that reveal their public keys. On the more optimistic side, Glassnode suggests that nearly 70% of the Bitcoin supply remains unexposed.
Regardless of the exact figure, the risk remains a fundamental concern for the utility or obsolescence of digital assets in the coming decade.
Ethereum’s advantage in this race lies in its programmable nature. While Bitcoin requires a soft or hard fork to implement new signature schemes, Ethereum’s use of ERC-4337 means developers can build these protections today as third-party wallet features. The Kohaku project’s proposal highlights that Ethereum’s modularity may be its greatest defense against emergent hardware threats.
Challenges in SPHINCS- wallet integration and adoption
Despite the low cost and technical feasibility, widespread adoption of SPHINCS- is not imminent. Nicolas Consigny noted that the system requires significant infrastructure development before it becomes a reality for the average user. There is currently a lack of audited tooling and wallet integrations necessary to make this “plug and play.”
User experience remains a major hurdle. For a user to benefit from SPHINCS-, they must first migrate their assets from a standard EOA (Externally Owned Account) to a smart contract wallet. This process itself incurs transaction fees and requires users to manage a new set of security protocols.
The complexity of this transition often scares away retail participants who prefer the simplicity of standard hardware wallets.
Future outlook for Ethereum account security
The focus on quantum security is indicative of a broader shift in the blockchain industry. Developers are no longer just looking at scaling through Layer-2 solutions; they are increasingly worried about “longevity risk.” As the CFTC and other regulators move toward more active oversight, the technical resilience of these networks becomes a matter of institutional safety.
If the SPHINCS- proposal gains traction among wallet providers like MetaMask or Safe, it could set a new industry standard for account-level security. Success would prove that decentralized networks can evolve to meet sophisticated threats without central coordination. For now, the proposal remains on the research side, awaiting the audits and developer interest necessary to bring the 7-cent quantum shield to the masses.
The road ahead will likely involve a mix of these voluntary account-level protections and eventual protocol-level changes. Developers are currently weighing whether a future Ethereum “hard fork” should eventually force all accounts into a quantum-resistant state, but such a heavy-handed move is unlikely as long as low-cost alternatives like SPHINCS- are viable.