Spiko Amundi Overnight Swap Fund (EUR) Post-Quantum Migration: What Holders Need to Know

The Spiko Amundi Overnight Swap Fund (EUR) post-quantum migration question is one of the most technically significant issues facing tokenised money-market funds on public blockchains right now. As quantum computing advances from theoretical threat to near-term engineering reality, any on-chain fund whose token balances are secured by ECDSA-based wallets faces a structural vulnerability. This article covers what Spiko and Amundi have said publicly about their roadmap, what a genuine post-quantum migration would require in practice, and what EUR fund holders can do in the interim to manage exposure.

What Is the Spiko Amundi Overnight Swap Fund (EUR)?

Spiko is a Paris-based fintech that brings regulated money-market funds onto public blockchains, most notably Ethereum and Polygon. Its flagship EUR product is the Amundi Overnight Swap Fund (EUR), a tokenised share class of Amundi's money-market fund investing primarily in overnight index swap instruments and short-duration euro-denominated debt. The fund targets the €STR (Euro Short-Term Rate) benchmark, making it a cash-equivalent instrument popular with treasuries, DAOs, and retail crypto holders seeking yield on idle stablecoins.

Each token represents a fractional share of the underlying regulated fund. Transfers are permissioned — only KYC-verified addresses can send or receive tokens — and the on-chain contract interacts with Spiko's smart-contract infrastructure to enforce compliance rules. The cryptographic security of token ownership ultimately rests on the same elliptic-curve assumptions (ECDSA / secp256k1 or secp256r1) that underpin every standard Ethereum wallet.

Why the Quantum Threat Is Relevant to a Tokenised Fund

Standard Ethereum key pairs use ECDSA over secp256k1. A sufficiently powerful quantum computer running Shor's algorithm could derive a private key from a public key in polynomial time, allowing an attacker to forge transaction signatures and drain any wallet whose public key has been exposed on-chain. For a tokenised fund this is a specific, concrete risk:

• Token balances are on-chain assets. Unlike a traditional fund where ownership lives in an off-chain register, token ownership is enforced by the blockchain. If the private key of a holder is compromised, the attacker can transfer those tokens to any whitelisted address they also control.
• Permissioning layers help but are not a complete fix. Spiko's compliance whitelist means an attacker needs a whitelisted destination address. However, a sophisticated quantum-capable adversary who can forge signatures could, over time, attempt social engineering to also compromise the whitelist, or exploit any edge cases in the upgrade logic.
• Dormant wallets are especially exposed. ECDSA public keys become visible the moment a transaction is broadcast from an address. Wallets that have transacted but hold a large balance are the most attractive targets once scalable quantum hardware arrives.

The NIST Post-Quantum Cryptography (PQC) standardisation process completed its first set of standards in 2024 (FIPS 203 ML-KEM, FIPS 204 ML-DSA, FIPS 205 SLH-DSA), providing the first formal baseline for migration.

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Does Spiko Amundi Overnight Swap Fund (EUR) Have a Post-Quantum Roadmap?

There is no public post-quantum migration plan or roadmap for the Spiko Amundi Overnight Swap Fund (EUR) as of the time of writing.

Spiko's published documentation focuses on regulatory compliance (AMF authorisation, MiCA alignment), gas optimisation, and cross-chain deployment. Neither Spiko's whitepaper, its developer documentation, nor Amundi's technology communications mention NIST PQC standards, lattice-based cryptography, hash-based signatures, or a timeline for migrating the fund's smart contracts or holder wallets to quantum-resistant schemes.

This is not unusual. The vast majority of tokenised real-world asset (RWA) issuers, including those from major TradFi institutions, have not yet published PQC roadmaps. The quantum threat is widely acknowledged in academic and standards communities but has not yet filtered into the product roadmaps of most on-chain fund managers.

What Spiko has communicated publicly is:

• Ongoing smart contract audits for conventional security vulnerabilities.
• A permissioned transfer model that reduces but does not eliminate quantum attack surfaces.
• Compliance with evolving EU digital asset regulation.

Holders should monitor Spiko's blog, Amundi's technology disclosures, and any future EU regulatory guidance under MiCA or DORA (Digital Operational Resilience Act) that may eventually mandate PQC standards for financial infrastructure.

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What a Post-Quantum Migration Would Actually Involve

If Spiko were to undertake a genuine post-quantum migration for the EUR fund, the process would be considerably more complex than a standard smart contract upgrade. The following outlines the key engineering and compliance layers.

1. Smart Contract Layer Migration

The fund's ERC-20-compatible token contract and its associated compliance logic would need to be redeployed or upgraded to support quantum-resistant signature verification. Options include:

• Account abstraction (ERC-4337) with PQC signature schemes. Smart contract wallets can implement custom signature validation, allowing ML-DSA or SLH-DSA signatures to authorise transactions without waiting for base-layer Ethereum to adopt PQC natively.
• New token contract deployment with migration event. A clean redeployment on a PQC-ready contract, with a snapshot-and-mint migration window for existing holders who prove ownership by burning old tokens. This is the most auditable approach but requires all holders to actively migrate.
• Proxy pattern upgrade. If the existing contract uses an upgradeable proxy (e.g. OpenZeppelin UUPS or Transparent), the implementation contract can be swapped to one that enforces quantum-resistant address schemes. This is faster but introduces upgrade-key risk during transition.

2. Wallet Infrastructure for Holders

Even if the contract is upgraded, holders must use wallets capable of generating and storing PQC key pairs. Today, no major consumer hardware wallet (Ledger, Trezor) or software wallet (MetaMask, Rabby) natively supports ML-DSA or SLH-DSA. Institutional custodians, notably Fireblocks and some HSM vendors, have begun post-quantum research programs, but production-ready PQC custody for EVM assets remains nascent.

3. Whitelist and KYC Infrastructure

Spiko's permissioned model means the compliance whitelist must also be migrated. Each whitelisted address would need to be re-verified and mapped to a new PQC-derived address. For a retail-facing platform this is a significant operational lift, requiring re-KYC or a cryptographic proof linking old ECDSA addresses to new PQC addresses.

4. Regulatory Coordination

As a regulated AMF fund, any material change to the fund's operational infrastructure, including its token contract, would likely require regulatory notification and possibly prospectus amendment. Amundi's compliance and legal teams would need to be involved, extending timelines significantly beyond what a purely technical migration would require.

5. Base Layer Dependencies

Ethereum itself does not yet have a PQC transition roadmap that has achieved rough consensus. The Ethereum Foundation has discussed quantum resistance at a research level (notably via the "Ethereum PQC working group" discussions on EthResearch), and Vitalik Buterin has written about hard fork migration paths, but no EIP has reached the Candidate for Inclusion stage. A tokenised fund on Ethereum is ultimately limited by what the base layer supports for consensus finality, even if application-layer PQC is implemented above it.

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Interim Risk Management Options for EUR Fund Holders

While waiting for any industry-wide or platform-specific migration, EUR fund holders have several practical options to reduce quantum exposure without exiting the position.

Use Fresh, Unexposed Addresses

The quantum risk is highest for addresses whose public keys are already on-chain. If you have transacted from a wallet, its public key is permanently visible. Moving your token balance to a fresh address (one that has never broadcast a transaction) provides meaningful near-term protection, because a quantum attacker cannot derive the private key from a public key that has never been revealed. This is a low-cost, immediately actionable step.

Prefer Institutional-Grade Custody

Institutional custodians are ahead of consumer wallets on PQC research. Custodians like Fireblocks, Anchorage, and Copper are actively evaluating post-quantum HSM configurations. Holding tokenised fund shares via an institutional custodian provides a faster migration path when production PQC custody becomes available.

Diversify Across Non-ECDSA-Dependent Instruments

For treasury managers allocating to tokenised money-market funds, maintaining a portion of liquidity in instruments that do not rely on on-chain ECDSA key custody, such as traditional T-bills, bank deposits, or off-chain money-market fund units, reduces concentration in quantum-exposed infrastructure.

Monitor NIST and EU Regulatory Timelines

NIST's 2024 PQC standards provide the reference point for migration. The EU's ENISA (European Union Agency for Cybersecurity) has published PQC migration guidance for critical infrastructure. DORA, which entered full application in January 2025, requires financial entities to address ICT risks systematically. Future DORA technical standards may explicitly require PQC readiness, which would directly accelerate timelines for regulated fund managers like Amundi.

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Comparing Post-Quantum Migration Approaches for Tokenised Funds

The table below summarises the main migration paths available to an on-chain tokenised fund issuer, comparing complexity, holder disruption, and time-to-security.

For a permissioned, regulated fund like Spiko's EUR offering, the custodian-level PQC approach is likely the most practical near-term path, since it does not require Ethereum base-layer changes and can be phased in via upgraded institutional custody integrations.

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The Broader Tokenised RWA Sector and Quantum Readiness

The Spiko Amundi fund is part of a rapidly growing tokenised RWA market that, by most estimates, surpassed $10 billion in on-chain assets under management in 2024. BlackRock's BUIDL fund, Franklin Templeton's FOBXX, and numerous other institutional products face the same structural quantum exposure. None have published PQC migration plans as of writing.

This creates a sector-wide gap between the pace of quantum hardware development (IBM's quantum roadmap targets utility-scale systems by 2029, with cryptographically relevant scale debated for the early 2030s) and the pace of on-chain financial infrastructure migration. The lead time for a regulated fund to plan, audit, gain regulatory approval for, and execute a migration is realistically two to four years. That math suggests issuers should be beginning feasibility work now.

Projects building natively on post-quantum cryptographic foundations, such as those using lattice-based schemes aligned with NIST FIPS 204/205, are positioned to avoid the migration problem entirely rather than retrofitting it. The BMIC quantum-resistant wallet, for example, is built from the ground up on lattice-based PQC, illustrating the difference between designing for Q-day from inception versus migrating legacy ECDSA infrastructure after the fact.

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Key Takeaways

• The Spiko Amundi Overnight Swap Fund (EUR) has no public post-quantum migration plan as of writing.
• The fund's token security rests on ECDSA, which is theoretically breakable by a sufficiently powerful quantum computer running Shor's algorithm.
• A genuine migration would require coordinated upgrades at the smart contract, wallet custody, whitelist, and regulatory layers, each with significant lead times.
• Holders can take interim steps: use fresh unexposed addresses, consider institutional custody, and monitor NIST and DORA regulatory developments.
• The broader tokenised RWA sector has yet to engage seriously with post-quantum migration, creating a systemic gap that regulators and issuers will need to address before cryptographically relevant quantum hardware arrives.