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Browse, search, filter
Nested folders with breadcrumb navigation. Filters: All / Images / Documents / Chat attachments. Image previews. Drag-and-drop upload and reordering.
Use case
Files fits naturally into this flow.
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Application · uFiles
Files.
Encrypted by default.
File management
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What you can do
What you can do
What you can do with Files.
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Per-file share with permissions
Per-file share dialog with read / write / admin permission and reshare toggle. “Shared with me” tab lists everything others have shared with you.
Use case
Files fits naturally into this flow.
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Cross-device live sync
Open the same folder on another device and edits appear live. The Personal Storage layer keeps your files encrypted, syncs them across devices, never reads them on the server.
Use case
Files fits naturally into this flow.
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Security
Security
Security for Files.
Every UltimaOS app shares the same post-quantum cryptographic stack, so the security properties below apply uniformly. App-specific considerations are noted where they apply.
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Post-quantum cryptography by default
All authentication and key exchange uses NIST-standardized ML-DSA-65 (FIPS 204) signatures and ML-KEM-768 (FIPS 203) key encapsulation. There is zero RSA, zero elliptic-curve, zero classical-only crypto in the authentication path. Defeats store-now-decrypt-later attacks.
02
End-to-end encryption on your device
Every payload is encrypted in your browser using XChaCha20-Poly1305 (RFC 8439) with a 192-bit nonce and a Poly1305 authentication tag. The plaintext exists only in your tab's memory. When you close the tab, the plaintext is gone.
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Zero-knowledge server
The UltimaOS server only ever stores ciphertext and public keys. We cannot read your data — by design, not by promise. There is no encryption backdoor, no master key, no key escrow.
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Multi-device sync, single private key
Your private key is derived from your passphrase using Argon2id with high parameters. New devices derive the same key locally and can decrypt your entire history. The passphrase is never sent to the server — it is verified by an ML-DSA-65 signature on a server-issued challenge.
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How it works
How it works
How Files works.
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01
Open Files in your browser
UltimaOS runs in any modern browser — Chrome, Firefox, Safari, Edge. Nothing to install. Sign in with your passphrase-derived key, or restore from a 3-of-5 social recovery if you are on a new device.
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Your data is encrypted before it leaves your device
Every action — sending a message, uploading a file, creating a task, scheduling an event — is encrypted with XChaCha20-Poly1305 and authenticated with an ML-DSA-65 signature before any byte crosses the network boundary.
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Server stores ciphertext, returns it on demand
The UltimaOS server keeps an opaque blob per account and per conversation. When you open Files, the encrypted blobs are streamed to your device, decrypted locally, and rendered. The server never sees plaintext.
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Changes sync to every device you sign in on
Any change you make is encrypted and uploaded; every other device you are signed in on pulls the new ciphertext and decrypts it. Live multi-device sync, with the cryptography guarantee that only your devices can read it.
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Inside the suite
Inside the suite
How Files fits in the suite.
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uChat
Drag-and-drop into a conversation. Files encrypts the attachment before it leaves your device.
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uMail
Drop attachments into the composer. Files encrypts and streams them to recipients.
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Boards
Card attachments use Files. Permissions and reshare inherit from Files.
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Documents
Documents can attach Files as inline images or downloads. Edits sync through Files.
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Get started
Get started
Get started with Files.
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01
Open Files in your browser
UltimaOS runs in Chrome, Firefox, Safari and Edge. Nothing to install. Sign in with your passphrase to derive your private key locally.
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Open the workspace and launch Files
The launcher shows every app. Files is right there with its capsule video preview. Click to open.
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Connect it with the rest of the suite
Files works alone, but it shines when combined with the rest of the UltimaOS apps. Same private key, same encryption, one workspace.
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Frequently asked
Common questions
Questions about Files.
Is Files end-to-end encrypted?
Short answer
Yes. All content in Files is encrypted in your browser using XChaCha20-Poly1305 with a fresh key per item. The UltimaOS server only ever stores ciphertext and public keys — it cannot decrypt your data, no matter who asks.
What cryptography does Files use?
Short answer
Files uses the same post-quantum stack as every other UltimaOS app: ML-DSA-65 (FIPS 204) for authentication, ML-KEM-768 (FIPS 203) for key encapsulation, XChaCha20-Poly1305 (RFC 8439) for symmetric encryption, HKDF-SHA256 for key derivation, and Argon2id for passphrase hashing.
Can I use Files on multiple devices?
Short answer
Yes. Sign in on any device with your passphrase and the same private key is derived locally. All your Files content is then decrypted from the encrypted blobs the server returns. Changes sync live across all signed-in devices.
Is Files GDPR-compliant?
Short answer
Yes. UltimaOS is built and operated in the European Union by an EU company. The architecture is GDPR-compliant by design — encrypted data, EU-only infrastructure, no US CLOUD Act exposure, no advertising, no third-party trackers. See the GDPR page for the full breakdown.
How much does Files cost?
Short answer
During early access, UltimaOS is free for individuals and organizations. After early access, pricing will be per-seat with accessible family tiers and per-organization plans for businesses. There is no per-app add-on.
Can I export my Files data?
Short answer
Yes. UltimaOS supports encrypted export of all your content for backup and portability. The export is encrypted to a key you control; you can store it on your own infrastructure or in a personal encrypted backup.
How much storage do I get?
Short answer
Storage scales with the seat tier you choose. Early access accounts get a generous quota out of the box; enterprise tiers scale into the multi-terabyte range.