Standard Edition
The QNSQY you can download today: post-quantum encryption (hybrid by default) and signatures for files, folders, backups and archives, on Linux and Windows. Available now
At a glance
| Version | The current release, with its release notes, is on the download page |
|---|---|
| Platforms | Linux x86-64 (.deb and .rpm, glibc 2.35 or newer), Windows 10 and 11 x64 (installer or portable program). No macOS or ARM builds yet. |
| Interfaces | Command line, desktop app, terminal app, and an MCP server for AI agents. One program. |
| Plans | Free, Pro and Business (pricing). Our billing server sets and signs your plan; nothing in the program unlocks a higher one. |
| Account | Needed for most features. Password encryption, ML-KEM-512 and ML-DSA-44 work without one. |
| Your data | Files, passwords and private keys never leave your device. Optional remote backup uploads only data encrypted on your device. |
Cryptography
| Function | Algorithms | Standard |
|---|---|---|
| Key exchange | ML-KEM-512, -768 and -1024 combined with X25519 (hybrid, the default). Business adds pure ML-KEM and HQC-128/192/256. | FIPS 203; RFC 7748; HQC is selected by NIST, not yet a published standard |
| Signatures | ML-DSA-44, -65 and -87, pure by default (hedged signing); ML-DSA + Ed25519 hybrids on Pro and Business; SLH-DSA (six parameter sets); FN-DSA-512 and -1024 (pre-standard Falcon); LMS (four parameter sets, Business). | FIPS 204; FIPS 205; SP 800-208; RFC 8032; FIPS 206 not yet published |
| Encryption | AES-256-GCM (default) or XChaCha20-Poly1305, chunk by chunk, with a Merkle tree over the chunks and a MAC over the header. | FIPS 197 and SP 800-38D; RFC 8439 |
| Password-based keys | Argon2id: 128 MB and 3 passes by default; stronger presets on Pro and Business. | RFC 9106 |
| Hashing and key derivation | SHA3-256, BLAKE3 and HKDF-SHA3-256 by default; a SHA-512 profile per file (SHA-512, HMAC-SHA-512, HKDF-SHA-512). | FIPS 202; FIPS 180-4; FIPS 198-1; RFC 5869 |
| Random numbers | The operating system's random generator. | - |
The Standard edition uses approved and non-approved algorithms together. For approved algorithms only, see Approved Mode.
Security features
- Network, Linux command line: after a short billing check-in, a kernel filter (seccomp) blocks every network call before any cryptographic work.
- Files, Linux: where the kernel supports Landlock, each QNSQY process restricts its own file access. It may use only its home, temporary, runtime and configuration folders, system folders (read-only) and the files and folders named on its command line (inputs read-only, the output folder writable). A guard also blocks the x32 system-call route.
- Network, Windows: Windows has no comparable kernel filter. Run as an administrator, each operation adds a firewall rule that blocks QNSQY's own outbound traffic and removes it afterwards; as a standard user QNSQY warns. For full isolation, disconnect the network.
- Desktop app: no window on X11 unless you allow it; every cryptographic operation runs in a separate command-line process that gets the password over a pipe. The command line is the most isolated way to use QNSQY.
- Memory: passwords and keys are kept out of swap where the system allows it, and most secret buffers are wiped when they are dropped.
- Tamper detection: the program checks a hash of itself when it starts.
- Signed releases: SHA-256 checksums signed with ML-DSA-87, a release key built into the program (
qnsqy verify-release), a software bill of materials with every release, and signed apt and dnf repositories. See the signing procedure. - Account traffic: sign-in and plan checks travel inside a post-quantum envelope (ML-KEM-1024 with X25519) within TLS, and carry no file contents, passwords or keys.
- Audit log: encrypted and hash-chained on every plan; Pro views and exports it; Business adds ML-DSA signatures on the chain.
- Security notices: signed-in Pro and Business apps name the fixed version when a released version has a security problem. Nothing stops working.
Tested
- 19,769 NIST ACVP test vectors through the open-source libraries QNSQY ships, 0 failures (September 2026 run; it tests those libraries, not QNSQY's own code), and 231 own-code vector tests, 0 failures.
- 4,884 Project Wycheproof adversarial vectors, 0 failures.
- 6 machine-checked protocol proofs and 185 Kani model-checking harnesses.
- Fuzzing: 1.01 billion executions (September 2026) and 7.9 million on the new signature-trailer parser (October 2026), 0 crashes.
- October 2026 release gate: 10,722 tests passed; the one failure was in an unreleased edition and was fixed before release.
Methods, raw logs and limits: Validation.
Limits, stated plainly
- Not FIPS 140-3 validated, not SOC 2 or ISO 27001 certified, no independent third-party audit yet.
- FN-DSA and HQC are pre-standard: NIST has not published their standards yet.
- Windows has no kernel-level network block, and the desktop app keeps network access for its billing check.
- Windows installers are not code-signed yet; no macOS or ARM builds; release builds are not yet byte-for-byte reproducible.
- Secure delete overwrites three times, but SSDs and copy-on-write file systems can keep old copies.