Is STON Quantum Safe? A Technical Analysis of Q-Day Risk

Is STON quantum safe? It's a question that matters more than most DEX users realise. STON.fi, the leading automated market maker on the TON blockchain, inherits its cryptographic security from TON's underlying signature scheme. When quantum computers reach sufficient scale, that scheme faces a fundamental threat. This article examines what cryptography STON and TON use, how a sufficiently powerful quantum computer could compromise user funds, what migration options exist, and how lattice-based post-quantum wallets represent a structurally different approach to protecting digital assets.

What Cryptography Does STON.fi Rely On?

STON.fi is a decentralised exchange built on The Open Network (TON). It does not issue its own layer-1 blockchain, so its cryptographic security is entirely inherited from TON's base-layer signature scheme.

TON uses EdDSA over Curve25519 (specifically the Ed25519 variant) for signing transactions and authenticating wallets. This is a modern, well-regarded elliptic-curve signature scheme that improves on the original Bitcoin/Ethereum ECDSA (secp256k1) in several practical ways: faster verification, smaller signatures, and resistance to certain implementation-level side-channel attacks.

However, Ed25519 and ECDSA share a critical structural weakness. Both derive their security from the hardness of the elliptic-curve discrete logarithm problem (ECDLP). A classical computer cannot solve ECDLP at any practical speed for 256-bit curves. A sufficiently large quantum computer running Shor's algorithm can.

Ed25519 vs ECDSA: Same Quantum Vulnerability, Different Surface

The takeaway: Ed25519 is a better classical scheme than ECDSA, but it offers no additional protection against a quantum adversary. Shor's algorithm breaks both in polynomial time once a sufficiently large fault-tolerant quantum computer exists.

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Understanding Q-Day: When Does This Threat Become Real?

Q-day refers to the future point at which a quantum computer with enough logical qubits and sufficient error correction can run Shor's algorithm against real-world elliptic-curve key sizes. Estimates from cryptographers and national security agencies vary, but several reference points are worth noting:

• NIST has been running its Post-Quantum Cryptography standardisation project since 2016, releasing final standards in 2024. The urgency of that timeline reflects genuine institutional concern.
• The NSA advised in 2022 that all systems should migrate away from elliptic-curve cryptography before 2035.
• IBM and Google have published quantum roadmaps showing exponential qubit scaling through the late 2020s.
• "Harvest now, decrypt later" (HNDL) attacks are already a live threat: adversaries collect encrypted blockchain data today and plan to decrypt it once quantum capability arrives.

For STON users specifically, the HNDL risk applies to any wallet address whose public key has been exposed on-chain. In TON's model, public keys are revealed when a transaction is first sent, meaning every wallet that has ever transacted is potentially harvestable.

What 4,000 Logical Qubits Means for Ed25519

A 2023 paper by Mark Webber et al. estimated that breaking a 256-bit elliptic-curve key would require approximately 317 × 10⁶ physical qubits under one noise model, or dramatically fewer under improved error correction. More optimistic engineering estimates put the threshold at a few thousand logical qubits, which may be achievable within 10 to 15 years on current hardware trajectories.

The point is not that this is imminent. The point is that cryptographic migrations take 5 to 10 years at ecosystem scale, and the window to begin planning is now, not after Q-day.

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STON.fi's Exposure at Q-Day: A Scenario Analysis

Scenario 1: Dormant Wallets With Exposed Public Keys

Any TON wallet that has signed at least one outgoing transaction has its Ed25519 public key recorded on-chain. A quantum adversary could, in principle, derive the private key from that public key using Shor's algorithm and drain the wallet. This exposure is not STON-specific, but STON liquidity providers and frequent traders are disproportionately likely to have active, high-value wallets that have transacted extensively.

Scenario 2: Smart Contract Signature Verification

STON.fi's smart contracts on TON verify Ed25519 signatures as part of transaction authentication. If the underlying signature scheme is broken, an attacker does not need the user's private key directly. They could forge a valid signature for any wallet address whose public key is known, authorising malicious transactions without the user's involvement.

Scenario 3: Protocol-Level Compromise vs. Wallet-Level Compromise

It is worth distinguishing two attack surfaces:

1. Wallet-level: An attacker breaks a specific user's private key and drains their personal holdings.
2. Protocol-level: An attacker targets validator keys, governance keys, or treasury multisigs to compromise the protocol itself.

Both are theoretically viable under quantum attack. Validator nodes on TON also use Ed25519 for consensus messaging, meaning a sufficiently resourced quantum attacker could potentially interfere with block production or double-sign. This is a lower-probability scenario but a higher-impact one for all STON liquidity pools simultaneously.

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Has STON or TON Published a Post-Quantum Migration Plan?

As of mid-2025, neither STON.fi nor the TON Foundation has published a formal post-quantum migration roadmap. This is not unusual for a project of STON's stage, but it is worth documenting:

• TON's whitepaper and technical documentation focus on sharding scalability, TVM smart contracts, and cross-chain interoperability. Post-quantum cryptography is not mentioned.
• STON.fi's public documentation covers liquidity pools, routing algorithms, and the STON governance token. No reference to cryptographic agility or PQC migration exists.
• The broader TON ecosystem roadmap (as published by the TON Foundation) does not include PQC milestones.

This does not mean migration is impossible. TON's virtual machine architecture could theoretically accommodate new signature schemes if validators and wallet developers coordinated a hard fork. But coordination at that scale is a multi-year undertaking, and the absence of current planning makes near-term migration unlikely.

How Other Layer-1s Are Approaching the Problem

For context:

• Ethereum has discussed account abstraction (ERC-4337) as a pathway to swap signature schemes without a hard fork, and the Ethereum Foundation has acknowledged PQC as a long-term research priority.
• Bitcoin has no formal PQC roadmap. Its developer community has discussed Pay-to-Quantum-Resistant-Hash (P2QRH) proposals but nothing is near consensus.
• QRL (Quantum Resistant Ledger) and IOTA built post-quantum signatures (XMSS, Winternitz OTS) into their base layers from inception.
• NIST-standardised algorithms (CRYSTALS-Kyber for key encapsulation, CRYSTALS-Dilithium for signatures) are being adopted in TLS, PKI, and government systems. Blockchain adoption is lagging.

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Lattice-Based Post-Quantum Cryptography: How It Differs

The NIST PQC standards that emerged from the 2016-2024 standardisation process are dominated by lattice-based schemes. Understanding why lattice cryptography resists quantum attack requires a brief look at the maths.

Why Lattices Resist Shor's Algorithm

Shor's algorithm exploits the period-finding structure of the integer factorisation problem and the discrete logarithm problem. Lattice problems, specifically the Learning With Errors (LWE) and Short Integer Solution (SIS) problems, do not have this algebraic structure. No known quantum algorithm (including Shor's and Grover's) reduces the hardness of LWE to polynomial time.

CRYSTALS-Dilithium (now FIPS 204: ML-DSA) produces signatures secure against both classical and quantum adversaries. Signature sizes are larger than Ed25519 (~2.4 KB vs 64 bytes for the lowest security level), but this is an acceptable trade-off for long-term security.

Lattice-Based Wallets vs. Ed25519 Wallets: Key Differences

Projects building wallets with lattice-based cryptography are positioning for the post-Q-day environment. One example is BMIC.ai, which is building a quantum-resistant wallet and token using NIST PQC-aligned lattice-based cryptography, specifically designed to protect holdings against the ECDSA and EdDSA exposure that platforms like STON currently carry.

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What STON Holders Should Think About Now

The quantum threat is not binary. There is no single day on which all elliptic-curve cryptography collapses simultaneously. The risk profile evolves with hardware capability, and prudent risk management means acting before the transition, not during it.

Practical considerations for STON and TON users:

1. Understand your exposure surface. If your wallet has sent at least one transaction, your Ed25519 public key is on-chain and harvestable. High-value wallets are higher-priority targets.
2. Monitor TON and STON migration announcements. If the TON Foundation initiates a PQC working group or publishes a migration proposal, that is a signal to act. Subscribe to TON governance forums and STON's official channels.
3. Consider cryptographic diversification. Holding assets across wallets that use different cryptographic schemes reduces concentrated exposure.
4. Watch the NIST adoption curve. As FIPS 203, 204, and 205 are integrated into operating systems, browsers, and network infrastructure through 2025 and 2026, expect blockchain projects to face increased pressure to adopt compatible schemes.
5. Evaluate new-generation wallets. Wallets built with post-quantum cryptography from inception do not face the same migration complexity as retrofitting a live blockchain.
6. Do not rely on obscurity. Some holders assume their wallets are too small to target. Quantum attacks, once the hardware exists, may be automated and broad rather than targeted.

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Summary: The Honest Verdict on STON's Quantum Safety

STON.fi is not quantum safe. Its security rests on TON's Ed25519 signature scheme, which, like ECDSA, is vulnerable to Shor's algorithm on a sufficiently powerful fault-tolerant quantum computer. No formal post-quantum migration plan has been published by STON.fi or the TON Foundation as of mid-2025.

This does not make STON a uniquely dangerous protocol. Virtually every major blockchain, including Bitcoin and Ethereum, shares this fundamental cryptographic exposure. What it does mean is that the quantum threat is an ecosystem-wide problem, and projects that address it proactively, at the wallet and protocol level, will be structurally better positioned as quantum hardware scales.

The honest answer to "is STON quantum safe?" is no, and the honest follow-up is that very few things in crypto currently are.