01
ML-DSA-65 (FIPS 204)
Digital signatures. Lattice-based, NIST-standardized in August 2024. Used for authentication, identity attestations, and key-receipt signatures.
00
Engineering
Engineering
Post-quantum cryptography. Zero-knowledge architecture.
The UltimaOS engineering stack is built on NIST-standardized post-quantum cryptography, deployed in a zero-knowledge architecture, on open, standardized specifications. The standards are public, the client ships as an inspectable single-page app, and the design is documented in the whitepaper; the backend is proprietary.
01
Overview
Cryptographic stack.
02
ML-KEM-768 (FIPS 203)
Key encapsulation. Lattice-based, NIST-standardized in August 2024. Used to establish fresh symmetric session keys for every peer-to-peer interaction.
03
XChaCha20-Poly1305 (RFC 8439)
Authenticated symmetric encryption. 256-bit key, 192-bit nonce, Poly1305 MAC. Used for every enveloped payload — chat, mail, files, notes, documents and spreadsheets.
04
HKDF-SHA256
HKDF-SHA256 for key derivation. Industry-standard primitives throughout.
02
Details
Architecture.
01
Zero-knowledge server
The server only ever stores ciphertext and public keys. No master key, no escrow, no backdoor. We cannot read your data — by architecture, not by promise.
02
End-to-end encryption, in the browser
Encryption runs in audited TypeScript libraries — @noble/post-quantum for ML-DSA-65 and ML-KEM-768 — inside your browser tab: the same code you can read in your developer tools. WebAssembly is supported as an asset type for PDF rendering and for Studio apps written by tenants; it is not part of the cryptographic stack. The plaintext exists only in tab memory. When you close the tab, the plaintext is gone.
03
Multi-device sync, single private key
Your private key is derived on your device from secrets only you control. Any device you sign in on derives the same key locally and can decrypt your history.
04
3-of-5 social recovery
Lose both your device and your passphrase? Three of five designated trustees can cooperatively regenerate your private key. No central authority can break the scheme.
03
Key points
Operations.
-
01
EU-only infrastructure
All data is stored in EU data centers operated under EU jurisdiction. There is no replication outside the EU, no US-based CDN, no backup to non-EU hyperscalers.
-
02
Inspectable client
The UltimaOS client runs in your browser on NIST-standardized algorithms you can verify against the public specifications, and ships as a standard single-page app whose cryptographic code, storage and sync can be inspected in developer tools. That is inspectability rather than mechanical verification: reproducible builds and signed build manifests are on the roadmap. The backend is proprietary; you can interrogate its behaviour from inside uOS, where uAI answers questions about it.
-
03
Transparency report
We will publish a transparency report when there is activity to report — government requests received, our response, and how we handled them.
05
Frequently asked
Engineering questions.
Can I inspect the UltimaOS client code?
Short answer
The client, yes — it ships to your browser as a standard single-page app, so its cryptographic code, storage layer and sync protocol can be inspected in developer tools. We describe that as inspectable rather than verified: shipped bundles are build artifacts, and reproducible builds with signed manifests are on the roadmap to close that gap. The backend is proprietary and not published — you can interrogate its behaviour from inside uOS, where uAI answers questions about it.
How do I report a security vulnerability?
Short answer
Email patrick@ultimaos.com. For sensitive disclosures, PGP-encrypted. We acknowledge within 24 hours and triage within 72 hours. See the security disclosure policy for details.
Does UltimaOS offer a public API?
Short answer
UltimaOS does not currently publish a public API or SDK. Within the product, uAI connects to the AI provider of your choice using your own API key, which stays on your device.
Do you publish a public roadmap?
Short answer
Yes. The current roadmap is documented on this site under “coming soon”. Customers and enterprise prospects get access to a more detailed internal roadmap.