Quantum Encryption Software

Quantum encryption software uses cryptographic algorithms designed to resist attacks from quantum computers. Traditional encryption like RSA and ECC relies on mathematical problems that quantum computers can solve efficiently using Shor's algorithm. Post-quantum cryptography uses different mathematical structures (lattices, codes, hash functions) that are believed to stay hard even for quantum computers.

QNSQY implements NIST FIPS 203 (ML-KEM) for quantum-safe key encapsulation, FIPS 204 (ML-DSA) for lattice-based digital signatures, FIPS 205 (SLH-DSA) for stateless hash-based signatures, FN-DSA (FIPS 206, not yet published; pre-standard Falcon implementation) for compact NTRU-based signatures, HQC for code-based key encapsulation, and LMS (SP 800-208) for stateful hash-based signatures. By default, ML-KEM is combined with X25519 for defense in depth. Signatures default to ML-DSA-44 on its own; Pro and Business can add Ed25519 to ML-DSA and SLH-DSA signatures, and Business adds FN-DSA hybrids. Business users can also choose pure ML-KEM, without X25519, for compliance profiles that require it.

Harvest now, decrypt later (HNDL) means recording encrypted data today and decrypting it once quantum computers can break the encryption. CISA, NSA and NIST warned in 2023 that threat actors could already be collecting data this way (see our guide to harvest now, decrypt later). Medical records, legal documents, financial data, and trade secrets encrypted with RSA or ECDH today could become readable, if a copy was recorded, once a cryptographically relevant quantum computer exists. Data that requires confidentiality for decades needs quantum-safe protection now.

The phrase "quantum encryption" is used for two different things. Quantum key distribution (QKD) uses the physics of light and dedicated hardware links to share keys. Post-quantum cryptography (PQC) is ordinary software built on math problems that quantum computers are not known to solve efficiently, and it runs on the computers and networks you already have. NIST published the first three PQC standards, FIPS 203, 204 and 205, in August 2024.

QNSQY is post-quantum cryptography: it needs no special hardware. For the background, see what post-quantum cryptography is.

1. NIST's final standards by name. Look for ML-KEM (FIPS 203) for key establishment and ML-DSA (FIPS 204) or SLH-DSA (FIPS 205) for signatures. Be wary of "quantum-proof" claims that name no algorithm.
2. Hybrid key establishment. Combining ML-KEM with a classical algorithm such as X25519 means a flaw in either one alone does not expose your data.
3. Validation status, stated plainly. FIPS 140-3 validation comes from NIST's Cryptographic Module Validation Program, and a vendor should give a certificate number you can look up. Some rules require it: NIST SP 800-171 Rev. 2 (requirement 3.13.11) asks for FIPS-validated cryptography to protect controlled unclassified information. QNSQY is not FIPS 140-3 validated.
4. Crypto-agility. Algorithm identifiers in every file and a versioned format let algorithms change without breaking old data.
5. Where the keys live. Encryption should happen on your own device, with keys the vendor never sees.
6. Evidence you can check. A published format specification, test-vector results and independent audits. Ask which of these exist and when they were done.
7. Platforms, offline use and price. Check the operating systems you need, whether it works without a network, and what each plan includes.

For US agencies, CISA's January 2026 list of product categories names web browsers and servers, chat and messaging, cloud platforms and data-at-rest security among the categories where PQC-capable products are already widely available. It notes that most have adopted PQC for key establishment but not yet for digital signatures.

• Web browsing: Chrome and Edge 131 and later, Firefox 132 and later on desktop, and Safari 26 use the hybrid X25519MLKEM768 key exchange by default (Cloudflare's support list).
• Libraries: OpenSSL 3.5 (April 2025) includes ML-KEM, ML-DSA and SLH-DSA.
• Remote access: OpenSSH 10.0 uses the hybrid mlkem768x25519-sha256 key agreement by default.
• Messaging: Signal added post-quantum keys to its protocol in 2023 (PQXDH).
• Email and files: GnuPG 2.5 adds Kyber (ML-KEM) encryption, and the older 2.4 series has reached end of life; age 1.3 (December 2025) adds post-quantum recipients; QNSQY encrypts files and folders with hybrid ML-KEM.

Plan	Price	Algorithms	File size (command line)
Free	$0, personal use	ML-KEM-512 + X25519, ML-DSA-44, AES-256-GCM or XChaCha20-Poly1305, Argon2id	No limit
Pro	$29 a month or $290 a year	All ML-KEM and ML-DSA levels, SLH-DSA, Ed25519 hybrid signatures	No limit up to ML-KEM-768; 25 GB per file with ML-KEM-1024
Business	$49 per user a month or $490 per user a year	Every algorithm, adding pre-standard FN-DSA and HQC, LMS and pure ML-KEM	No limit
Enterprise	By scope	Everything in Business, plus government builds	No limit

The desktop app is stricter: it will not encrypt a file over 100 MB on Free or over 25 GB on Pro. Full details are on the pricing page.

• It is a post-quantum cryptography tool for Linux (x86-64 and ARM64) and Windows, with a command line, desktop app, terminal UI and MCP server in one binary. It encrypts on your device, its .qs file format specification is published, and in its 2026-09-24 test-vector sweep the ML-KEM, ML-DSA and SLH-DSA implementations it uses passed all of NIST's ACVP vectors (validation evidence).
• It is not FIPS 140-3 validated, SOC 2 or ISO 27001 certified, or independently audited: it has had no third-party cryptographic audit or penetration test yet. There is no macOS version yet (it has a waitlist) and no mobile app, and it is not a cloud storage service.

What is quantum encryption software?

Software that protects data with algorithms designed to resist quantum computers, usually NIST's post-quantum standards: ML-KEM (FIPS 203) for key establishment and ML-DSA (FIPS 204) or SLH-DSA (FIPS 205) for signatures. Shor's algorithm, which breaks RSA and elliptic curves, does not break them.

Is quantum encryption the same as quantum key distribution (QKD)?

No. QKD uses physics and dedicated hardware links to share keys. Post-quantum cryptography is ordinary software on existing computers and networks. QNSQY is post-quantum cryptography.

Why do I need quantum-safe encryption now?

Because data can be recorded today and decrypted later. CISA, NSA and NIST warned in 2023 that threat actors could already be collecting data this way (harvest now, decrypt later), so data that must stay secret for years needs post-quantum protection before a large quantum computer exists.

Is QNSQY free quantum encryption software?

Yes, for personal use. The Free plan includes ML-KEM-512 + X25519 hybrid encryption with no file-size limit on the command line, ML-DSA-44 signatures, AES-256-GCM and XChaCha20-Poly1305, and Argon2id. ML-KEM-768/1024 and SLH-DSA need Pro or Business.

What algorithms does QNSQY use?

ML-KEM (FIPS 203), combined with X25519 by default, for key establishment; ML-DSA (FIPS 204), SLH-DSA (FIPS 205) and LMS (SP 800-208) for signatures; and the pre-standard HQC and FN-DSA on Business. Data is encrypted with AES-256-GCM or XChaCha20-Poly1305, passwords are stretched with Argon2id, and BLAKE3 and SHA3-256 are used for hashing and key derivation. Signatures are ML-DSA-44 on their own by default; Pro and Business can add Ed25519.

Is QNSQY FIPS 140-3 validated?

No. QNSQY is not FIPS 140-3 validated, and it has had no independent third-party audit yet. Its test-vector evidence and file format specification are published, but they are not a certification.

How much does QNSQY cost?

Free for personal use. Pro is $29 a month or $290 a year. Business is $49 per user a month or $490 per user a year, self-serve. Enterprise pricing depends on scope.

Download QNSQY and secure your sensitive data against quantum threats. The free tier includes ML-KEM-512 + X25519 hybrid encryption, AES-256-GCM or XChaCha20-Poly1305, and Argon2id key derivation. No account required.

Migrating a database, replicated store, or cold-storage archive off classical cryptography is a separate engagement. See Professional Services.