USX USX

Claim: USX/Solstice Finance has not published a cryptographic inventory or quantum threat model. The token's cryptographic profile (Ed25519 spend authorization, PDA minting) is derivable from Solana documentation and Solstice smart contract docs.

Coverage basis: No project-specific publication; cryptographic profile derivable from L1 documentation

Implementation score: 0.25 · Evidence confidence: Medium

Issue classification: quantum-critical uncertainty · Score treatment: score-reducing

Assurance: Cryptographic inventory for USX is inferable from Solana's published analyses and Solstice documentation but no project-specific publication exists.

Solana Foundation, Anza, and Firedancer have published detailed quantum analyses for the L1. USX inherits this indirectly but Solstice has not published its own assessment.

• https://docs.solstice.finance/solstice-for-builders/smart-contracts
• https://solstice.finance/security
• https://solana.com/news/quantum-readiness
• https://www.helius.dev/blog/what-would-solana-need-to-change-to-become-quantum-ready

Claim: No project-specific evidence record (code references, transaction examples, reproducible analytics) has been published by Solstice Finance for quantum readiness.

Coverage basis: No project-specific evidence; Solana L1 evidence exists but is not USX-specific

Implementation score: 0.25 · Evidence confidence: Medium

Issue classification: quantum-critical uncertainty · Score treatment: score-reducing

Assurance: Solana L1 has published Falcon implementations on GitHub and testnet PQ signatures. USX token transfers would benefit from L1 migration but no USX-specific evidence exists.

Evidence record is available at the L1 level only. Token-specific governance paths (multisig) are not covered by L1 evidence.

• https://github.com/anza-xyz/cryptography/pull/10
• https://github.com/firedancer-io/firedancer
• https://blueshift.gg/research/quantum-proofing-solana

Claim: USX token transfers use Solana's Ed25519 signature scheme. Solana mainnet does not support PQC or hybrid-PQC transaction signatures. All USX spend authorization is Ed25519-only.

Coverage basis: Inherits Solana L1 Ed25519-only spend authorization

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Quantum blocker: All USX spend authorization is Ed25519-only on mainnet. Quantum-enabled key recovery from exposed public keys enables theft of any USX balance.

Assurance: Confirmed by multiple independent sources including Solana Foundation, Helius research, and Jump Crypto.

Solana has Falcon implementations on GitHub and testnet PQ signatures (Project Eleven, April 2026), but mainnet default remains Ed25519. SIMD-0416 proposes Falcon verification syscall; not yet on mainnet.

• https://www.helius.dev/blog/what-would-solana-need-to-change-to-become-quantum-ready
• https://solana.com/news/quantum-readiness
• https://jumpcrypto.com/resources/quantum-migration-paths-for-solana

Claim: USX holder addresses are Solana Ed25519 public keys. All externally owned accounts (EOAs) that have sent transactions expose their public keys on-chain. Over 60% of funded Solana addresses have made outgoing transactions, creating long-exposure quantum-vulnerable surfaces. PDAs used for minting are quantum-resistant by design (hash-derived, off-curve).

Coverage basis: Inherits Solana address model; partial protection from PDA architecture

Implementation score: 0.25 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Assurance: Solana's Ed25519 key derivation uses SHA-512 hashing of the seed, which provides quantum-resistant seed protection — enabling emergency migration via ZK-proof of seed knowledge. This is a recoverability property, not production protection.

PDAs (Program Derived Addresses) are provably off-curve and have no private keys, making them quantum-resistant for mint authority and program state. USX uses PDA-controlled minting, which is a genuine quantum-resistant property for supply integrity. However, user-held USX balances in EOAs remain fully exposed.

• https://www.helius.dev/blog/what-would-solana-need-to-change-to-become-quantum-ready
• https://blueshift.gg/research/quantum-proofing-solana
• https://quantumwalletcheck.com/learn/solana-quantum

Claim: Solana consensus (Alpenglow) uses BLS12-381 signatures for validator votes and certificates. BLS12-381 is pairing-based elliptic curve cryptography, vulnerable to Shor's algorithm.

Coverage basis: Inherits Solana L1 consensus mechanism

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Assurance: A quantum attacker forging consensus votes could enable double-spend attacks on the Solana network, affecting USX settlement finality. Research on Falcon aggregation and lattice-based multisignature protocols (Raccoon, DOTT) is ongoing.

Consensus compromise would affect all SPL tokens including USX. This is an inherited L1 risk.

• https://jumpcrypto.com/resources/quantum-migration-paths-for-solana
• https://www.anza.xyz/blog/securing-solana-against-a-powerful-quantum-adversary

Claim: USX uses PDA-controlled minting (SHA-256 hash-derived addresses, provably off-curve, no private key). The USX program is claimed non-upgradeable. However, multisig-controlled administrative parameters (whitelisted accounts, collateral registration, custodian authorization, emergency fund movements) use Ed25519 signers. Solana's state integrity uses SHA-256 Merkle trees (quantum-resistant).

Coverage basis: PDA minting is quantum-resistant by design; multisig admin path is Ed25519-vulnerable. Solana state layer is hash-based.

Implementation score: 0.5 · Evidence confidence: Medium

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Quantum blocker: Multisig-controlled administrative parameters (whitelisted accounts, custodian authorization, emergency fund movements) rely on Ed25519 signers. A quantum attacker compromising 3 of 5 signers could manipulate protocol operations.

Assurance: The claim of non-upgradeable programs appears on the security page but conflicts with documentation stating upgrade authority is held by multisig. On-chain verification was not performed in this evaluation. Halborn/Sep2 audits confirm PDA-controlled minting architecture.

PDA minting is a significant quantum-resistant property: the mint authority cannot be compromised via Shor's algorithm because PDAs have no private keys. However, the multisig that controls operational parameters remains quantum-vulnerable. If the program is actually upgradeable (contradicting the security page claim), the multisig vulnerability extends to full program compromise.

• https://docs.solstice.finance/solstice-for-builders/smart-contracts
• https://solstice.finance/security
• https://blueshift.gg/research/quantum-proofing-solana
• https://www.helius.dev/blog/solana-post-quantum-cryptography

Claim: USX has no privacy layer, shielded transactions, or zero-knowledge proof systems.

Coverage basis: No privacy layer exists

Implementation score: 0 · Evidence confidence: High

Issue classification: none · Score treatment: not applicable

Claim: USX is an SPL token with no P2P networking layer of its own. P2P security is inherited from Solana L1.

Coverage basis: No token-level P2P layer

Implementation score: 0 · Evidence confidence: High

Issue classification: none · Score treatment: not applicable

Claim: USX program governance uses a Squads 3/5 multisig with Ed25519 signer keys. No PQ or hybrid-PQ signing workflows are documented for the multisig signers. No hardware wallet or HSM PQ support is documented.

Coverage basis: Multisig signers are Ed25519-only; no PQ workflow documented

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Quantum blocker: Squads 3/5 multisig signers use Ed25519 keypairs. Quantum key recovery of 3 signers enables full administrative control of the USX protocol.

Assurance: Squads Protocol v4 program (SQDS4ep65T869zMMBKyuUq6aD6EgTu8psMjkvj52pCf) has been audited by OtterSec, Neodyme, Certora, and Trail of Bits, but these are general smart contract audits, not quantum-specific. Solana's Winternitz Vault/Winterwallet could theoretically protect signer keys but no evidence of adoption by Solstice signers exists.

The Blueshift Winterwallet provides a PQ path for Solana signing authorities using Winternitz One-Time Signatures. Solstice multisig signers could adopt this today without protocol changes, but no evidence of adoption exists.

• https://docs.solstice.finance/solstice-for-builders/smart-contracts
• https://solstice.finance/security

Claim: USX has $501M+ TVL across 30K+ holders on Solana. All USX is held in Ed25519-secured accounts on a network with no production PQ protection. Less than 1% of value could be in Winternitz Vault (Solana's optional PQ vault, SOL-only, limited adoption).

Coverage basis: All USX value is on Solana mainnet with Ed25519-only protection

Implementation score: 0.05 · Evidence confidence: Medium

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Quantum blocker: $501M+ in USX TVL is quantum-vulnerable with <1% protected. No migration, freeze, or deprecation path exists for vulnerable USX balances.

Assurance: TVL figure from Solstice website ($501M+, as of evaluation date). The Winternitz Vault on Solana provides optional PQ protection for SOL only (not SPL tokens) and has limited adoption. USX holders cannot directly use it for USX protection.

Value-at-risk assessment follows Section 9.3.1: <25% coverage maps to score 1 out of 20 (Implementation Score 0.05). The $501M TVL figure represents nominal on-chain USX supply. Underlying collateral (USDC/USDT) on other chains adds indirect quantum risk not scored here.

• https://solstice.finance/usx
• https://quantumwalletcheck.com/learn/solana-quantum
• https://blueshift.gg/research/quantum-proofing-solana

Claim: USX multisig signers (3/5 Squads), whitelisted minting accounts, and program upgrade authority all use Ed25519 keypairs. No migration to PQ keys has occurred. No evidence of Winterwallet or other PQ protection adoption by Solstice administrators.

Coverage basis: No critical wallet migration has occurred

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Quantum blocker: No critical wallet (multisig signers, whitelisted minters, upgrade authority) has been migrated to PQ keys.

Assurance: Solstice could adopt Winterwallet for multisig signers today. The Blueshift team explicitly recommends this for 'upgrade authorities and signing keys that control high-value programs and mints.' No evidence of adoption.

The PDA-controlled mint authority is inherently PQ-native (no private key), which provides partial protection for the minting function. However, whitelisted accounts that can invoke minting are Ed25519-secured.

• https://docs.solstice.finance/solstice-for-builders/smart-contracts
• https://solstice.finance/security

Claim: No inventory of quantum-vulnerable USX holding addresses has been published. No deprecation, freeze, or migration mechanism exists for dormant or unmigratable USX positions.

Coverage basis: No identification or deprecation of vulnerable pools

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical uncertainty · Score treatment: score-reducing

Assurance: Solana L1 has identified the exposed-public-key problem (>60% of addresses have sent transactions) and proposed migration paths (ZK-proof of seed knowledge, commit-and-reveal). USX has not published its own analysis.

USX as an SPL token cannot independently freeze or migrate user balances without token-level freeze authority, which is not documented as enabled for USX.

Claim: Solana L1 has published a 3-phase quantum roadmap (Falcon research, new wallet adoption, existing wallet migration). USX/Solstice has published no token-specific roadmap.

Coverage basis: Solana L1 roadmap exists; no USX-specific roadmap

Implementation score: 0.25 · Evidence confidence: Medium

Issue classification: quantum-critical uncertainty · Score treatment: score-reducing

Assurance: Solana's roadmap covers L1 account migration. USX token transfers would automatically benefit from the L1 Falcon migration. However, token-specific admin key migration is not addressed by the L1 roadmap.

A token-specific roadmap would need to address: multisig signer key migration to PQ, whitelisted account migration, and coordination with Solana's Falcon activation timeline.

• https://solana.com/news/quantum-readiness
• https://www.anza.xyz/blog/securing-solana-against-a-powerful-quantum-adversary
• https://jumpcrypto.com/resources/quantum-migration-paths-for-solana

Claim: Solana has the Winternitz Vault and Winterwallet (Blueshift) providing optional PQ protection on mainnet. No USX-specific tooling, wallet integration, custody path, or user education exists.

Coverage basis: Optional L1 tooling exists; no USX-specific tooling

Implementation score: 0.25 · Evidence confidence: Medium

Issue classification: operational/product caveat · Score treatment: score-reducing

Assurance: Winternitz Vault currently supports SOL only, not SPL tokens. Winterwallet is an end-to-end wallet for PQ signing on Solana. USX tokens in Winterwallet-controlled accounts could theoretically be PQ-protected, but no integration or documentation exists.

No USX-specific migration prompts, warnings, or educational materials exist. Users are not informed of quantum risk.

• https://blueshift.gg/research/quantum-proofing-solana
• https://solana.com/news/quantum-readiness

Claim: No enforcement mechanisms exist for USX migration. No deprecation deadlines, disabled legacy signing, restricted withdrawals, or mandatory migration requirements. No exchange, custody, or wallet coordination for USX-specific migration.

Coverage basis: No enforcement or coordination mechanisms exist

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical vulnerability · Score treatment: score-reducing

Assurance: Solana L1 has not yet activated any enforcement mechanisms. The Falcon migration remains optional and future-dated. USX cannot enforce migration independently without token-level freeze authority.

USX has no cross-chain bridges (Solana-native only), which reduces coordination complexity for migration but does not eliminate the need for enforcement mechanisms.

Claim: No quantum-specific emergency disclosure process, incident-response plan, or governance procedure has been published by Solstice Finance for USX.

Coverage basis: No quantum-specific emergency process exists

Implementation score: 0 · Evidence confidence: High

Issue classification: assurance-only caveat · Score treatment: note-only

Assurance: Solstice has general security monitoring (Hypernative), 24-hour timelock on admin actions, and a security page. No quantum-specific processes are documented. Per Section 7.4, lack of a formal quantum-specific IR playbook is a note-only caveat when it does not leave a current quantum-vulnerable path unresolved.

The 24-hour timelock on administrative transactions provides a limited window for emergency response to detected multisig compromises. Hypernative monitoring could potentially detect anomalous admin activity.

• https://solstice.finance/security

Claim: USX has no custom cryptographic algorithms. All cryptography is inherited from Solana L1, which currently uses Ed25519 (not PQ). Solana has selected Falcon (FN-DSA, NIST FIPS 206 draft) as its future PQ scheme with implementations on GitHub, but this is not yet on mainnet.

Coverage basis: No token-specific algorithms; inherits Solana L1

Implementation score: 0 · Evidence confidence: High

Issue classification: none · Score treatment: not applicable

Assurance: When Solana L1 deploys Falcon on mainnet, USX token transfers will automatically use Falcon signatures without token-level changes. This is an L1 concern.

• https://solana.com/news/quantum-readiness
• https://jumpcrypto.com/resources/quantum-migration-paths-for-solana

Claim: USX smart contracts have been audited by Halborn (3x) and Sep2 for general security (access controls, economic attack vectors, program logic). No quantum-specific audit scope exists. The multisig governance path has not been audited for quantum resistance.

Coverage basis: General smart contract audits only; no quantum-specific audit

Implementation score: 0 · Evidence confidence: Medium

Issue classification: assurance-only caveat · Score treatment: score-reducing

Assurance: Halborn and Sep2 audits confirm PDA-controlled minting architecture and access controls. These are valuable for classical security but provide no quantum-specific assurance. The quantum-critical scope (Ed25519 multisig vulnerability, PDA quantum resistance) is not covered. Per Section 6.4, scope-mismatched audits support only the audited component and limit confidence for unaudited production scope.

The Squads Protocol v4 program used by the multisig has been independently audited by OtterSec, Neodyme, Certora (with formal verification), and Trail of Bits. These are general smart contract audits, not quantum-specific.

• https://solstice.finance/security
• https://storage.googleapis.com/dapp_prod/audit_reports/halborn_program_audit_250605.pdf

Claim: USX program source code is not publicly available on GitHub or any open-source repository. The SDK is distributed via private NPM (@solsticelabs/usx-client-sdk). On-chain program addresses are published and verifiable on Solana Explorer, but source code cannot be independently reviewed or reproduced.

Coverage basis: Closed-source; on-chain bytecode only

Implementation score: 0 · Evidence confidence: High

Issue classification: quantum-critical uncertainty · Score treatment: score-reducing

Assurance: Closed-source code prevents independent verification of quantum-critical claims including PDA-controlled minting, non-upgradeable status, and multisig parameters. On-chain bytecode verification is possible but source-level review is not. This primarily affects Evidence Confidence.

The Solstice website states 'All addresses verifiable on Solana Explorer.' On-chain programs can be decompiled but source-level audit is not possible without access to the private repository.

• https://docs.solstice.finance/solstice-for-builders/sdk
• https://docs.solstice.finance/solstice-for-builders/smart-contracts

Claim: USX has no PQ cryptographic parameters of its own. Parameter agility is not applicable at the token level.

Coverage basis: No token-level PQ parameters exist

Implementation score: 0 · Evidence confidence: High

Issue classification: none · Score treatment: not applicable

Claim: USX has no PQ signing implementation of its own. No stateful signature schemes (XMSS/LMS) are in use at the token level.

Coverage basis: No PQ signing implementation at token level

Implementation score: 0 · Evidence confidence: High

Issue classification: none · Score treatment: not applicable

If Solstice multisig signers adopt Winterwallet (Winternitz OTS), stateful-signature safety becomes relevant. WOTS requires strict single-use key management, which Winterwallet handles transparently.

Claim: No USX-specific performance analysis exists. Solana L1 has analyzed the impact of Falcon signatures: Project Eleven's testnet deployment showed 90% throughput reduction with Dilithium; Falcon is expected to be more efficient (10x signature size increase over Ed25519, 3x faster verification).

Coverage basis: No token-specific analysis; L1 analysis exists

Implementation score: 0 · Evidence confidence: Medium

Issue classification: none · Score treatment: not applicable

Assurance: Solana's expected Falcon migration would increase transaction sizes ~10x (from 64-byte Ed25519 to ~666-byte Falcon signatures). This could affect USX transfer costs and throughput but is manageable within SIMD-0296's 4096-byte limit.

• https://github.com/soqucoin/soqtec
• https://jumpcrypto.com/resources/quantum-migration-paths-for-solana