Stored in the EU
Stored ciphertext does not by itself guarantee protection against a compromised authentication service or modified client code. Review the trust boundary on our Security page.
Your files are encrypted on your device. We store only the encrypted version.
Files are encrypted on your device before upload, so our servers only ever hold the encrypted version. The Security page documents what we can still see, such as sign-in and operational metadata, and how web and Android encryption differ.
ShieldFive exists because cloud storage kept adding "AI" features that needed plaintext access. The intended model (store an encrypted blob, hand over the key, leave it alone) didn't really exist past the niche, and the products that came closest (Proton Drive, Mega, Internxt) all had specific gaps to close.
If a readable copy of your files exists on a server, someone can ask for it. So we made sure none does. And we document exactly where that guarantee stops.
The design constraint was deliberate: build the storage system and ship the cryptography library separately so anyone can audit exactly what runs in the browser.
That constraint is easiest to see in practice: how accounting and CPA firms share client documents, and what zero-knowledge storage actually guarantees.
We would rather show you where the line sits than pretend there isn’t one.
What we can see. And what we can't.
The most honest privacy claim is not "we see nothing." It is showing you exactly where the line sits, and why it sits there.
File handling and its limits
Your file contents. Encrypted on your device before they upload.
File and folder names. Stored only as ciphertext, encrypted with the contents.
Your encryption keys. Unwrapped locally. Your password never reaches our servers: the browser sends only an Argon2id-derived login value. The client code we deliver remains part of the trust boundary.
Operational metadata. We process account, billing and operational metadata, including link access information used to enforce sharing controls. The Privacy Policy lists what is collected and why.
Anything a model could train on. File contents are uploaded encrypted. We do not use file contents for AI training. Read Security for the authentication and client-code trust boundary.
What we do see, and why
Your account email. To sign you in and send account notices.
Billing details. Handled by our payment processor. Card data never touches our servers.
Storage used and your plan. To keep your quota accurate.
Ciphertext metadata and timestamps. Sizes, upload status, and times. The minimum needed to sync reliably.
Sign-in credentials. Your password never reaches our servers. The browser turns it into a separate login value (Argon2id) and sends only that; the key that opens your vault is derived separately and stays on your device. The app code is delivered by us, so you still trust the client we serve on each visit.
File contents are encrypted before upload. Authentication and operational metadata are separate; see Security and Privacy.
Where it lives. And what locks it.
Hybrid post-quantum encryption on web and Android
The web client and the Android app use ML-KEM-1024 and XChaCha20-Poly1305 hybrid encryption by default for new uploads, with a documented AES-256-GCM fallback. Android reads both formats. See Security for the formats and limitations.
Five rules.Enforced by design.
01
Uncompromising Security
Files are encrypted on your device with per-file keys and strong defaults, including post-quantum hybrid encryption on web and Android. Security is the foundation, not a feature.
02
People Over Surveillance
No ads, no selling data, no AI pipelines, no hidden processing. You're the customer - not the product.
03
Built for Real-World Threats
For journalists under pressure, lawyers with sensitive cases, activists facing retaliation, and anyone tired of being read.
04
No dark patterns
No tracking pixels. No engagement loops. No upsell theater. The product is the product.
05
Aligned with you
Your subscription is our revenue, so there's no pressure to monetize what you store. Pricing pays the bills. That's it.
A logo proves nothing. So we did the things a logo can't fake.
A certificate is a claim about a report you cannot read. Instead of buying a badge, we made the things that matter checkable by anyone, today.
Open-source cryptography
Every line of @shieldfive/crypto is public. Read exactly what runs in your browser before a byte uploads.
Read the codePublished security review
Six task documents and a triage table from the internal review of the crypto library, published in full.
Read the reviewPublished threat model
We document exactly what we defend against, and what we do not. No vague "military grade" claims.
Read the threat modelON EXTERNAL AUDITS
We haven't commissioned a third-party security audit yet, and we won't pretend we have. It is on the roadmap. Until then, open code and a published security review are stronger than a private report you would have to take on faith.
"Your password never reaches our servers. The browser turns it into a separate login value (Argon2id) and sends only that; the key that opens your vault is derived separately and stays on your device. The app code is delivered by us, so you still trust the client we serve on each visit."
Cho García
Founder