Post-quantum (ML-KEM-1024) zero-knowledge cloud storage

Your files are nottraining data.

ShieldFive encrypts your files before they leave your device, so even we can’t read them.Privacy is not a promise. It is system design.

Create your private vault

Post-quantum (ML-KEM-1024) by default · Zero-knowledge · Open-source · EU-hosted

Architecture check

Ciphertext only

Encrypted before upload

Server receives unreadable ciphertext

Key stays with you

No plaintext. No training data. No backdoor access.

20 GBFree to start — no card required
100%Open-source crypto
0Readable files on our servers
5Open protocols — no lock-in

What this is

Cloud storage where the platform is locked out.

ShieldFive stores encrypted data, not readable files. Your browser encrypts the file first. The server receives ciphertext. Without your key, the file is meaningless.

01

File selected

Choose the document, photo, archive, or backup you want to protect.

02

Encrypted locally in browser

Encryption runs on your device before network transfer begins.

03

Ciphertext uploaded

The upload contains encrypted bytes, not readable file contents.

04

Stored encrypted

ShieldFive stores ciphertext only, separated from the key needed to open it.

05

Decrypted only on your device

Opening a file requires your key and happens back on your device.

Encrypted before upload. Ciphertext only.

The problem

Most cloud storage still depends on access.

Server-side access exists for features.

Most cloud storage providers retain server-side access for indexing, sync, security scanning, previews, integrations, or compliance.

Readable files create AI exposure.

When a platform can process plaintext, privacy depends on settings, contracts, and future policy choices.

Promises are weaker than architecture.

If the provider can read a file, users must trust that access will never be expanded, misused, or compelled.

Reality check

If plaintext exists on a server, someone can ask for it.

ShieldFive is designed so our servers never receive plaintext in the first place.

Comparison

Compare the architecture, not the marketing.

Encrypted storage is a spectrum. The important question is who can access file contents, filenames, and keys by design.

Proton Drive
Content encryption
AES-256 (OpenPGP-based), per-file
Post-quantum hybrid (default)
Mail: opt-in via OpenPGP v6 (May 2026); Drive: no
Per-file content keys
Yes
Geofenced share links
No
Share without recipient account
Yes, via link
Open-source crypto
Client open-sourced
Hosting jurisdiction
Switzerland
Mega
Content encryption
AES-128, per-file
Post-quantum hybrid (default)
No
Per-file content keys
Yes
Geofenced share links
No
Share without recipient account
Yes, via link
Open-source crypto
Client open-sourced
Hosting jurisdiction
New Zealand
Internxt
Content encryption
AES-256
Post-quantum hybrid (default)
Kyber-512 (pre-FIPS)
Per-file content keys
Unknown
Geofenced share links
No
Share without recipient account
Yes, via link
Open-source crypto
Clients open-sourced
Hosting jurisdiction
Spain (EU + global DCs)
ShieldFive
Content encryption
AES-256-GCM, per-file
Post-quantum hybrid (default)
ML-KEM-1024 + XChaCha20-Poly1305
Per-file content keys
Yes
Geofenced share links
Yes
Share without recipient account
Yes, via link
Open-source crypto
Library open-sourced (@shieldfive/crypto)
Hosting jurisdiction
EU (Germany)

~ = partial or qualified. Comparison reflects publicly documented behavior of each service as of 2026-05-15. ShieldFive’s post-quantum row was flipped to good on 2026-05-17 when Suite 0x03 became the production default for new uploads; Internxt row sourced as of 2026-05-15 unchanged. Proton row’s post-quantum cell updated 2026-05-18 to reflect Proton Mail’s OpenPGP v6 post-quantum launch on 2026-05-05 (opt-in, email product only); Proton Drive’s storage wire format had not adopted post-quantum as of 2026-05-18. Each row sourced from each vendor’s public documentation. Internxt row sources: internxt.com/drive, internxt.com/privacy, blog.internxt.com/post-quantum-cryptography (Jan 17 2025), github.com/internxt — accessed 2026-05-15. Proton post-quantum source: proton.me/blog/introducing-post-quantum-encryption — accessed 2026-05-18.

Create your private vault

Start free, then upgrade only when you need more private storage.

Local encryption demo

Proof you can feel. Not theater.

Drop a file to run a real browser encryption demo. Nothing is uploaded. Large files are sampled locally for speed; the production vault uses streaming encryption for full uploads.

Drop a file to encrypt it locally

or click to browse · runs in your browser · nothing is uploaded

Create your private vault

The real product applies this principle to your cloud storage workflow.

The five protocols

Privacy isn't a setting. It's the architecture.

Five product rules keep the promise simple: encrypt before upload, hide metadata where possible, reduce crawler exposure, keep user rights intact, and sell storage instead of data.

Design constraints

The list most cloud companies avoid publishing.

These are not marketing promises. They are product constraints created by client-side zero-knowledge encryption.

We cannot read your files

Your browser encrypts before upload. ShieldFive stores ciphertext and does not receive the key needed to read it.

Encrypted before upload

We cannot train AI on your files

AI systems cannot train on plaintext we never receive. No plaintext. No training data.

Ciphertext only

We cannot recover your files if you lose your key

Zero-knowledge means support cannot bypass your password or recovery phrase. Keep them somewhere safe.

User-held key

We cannot silently change the architecture

The product promise depends on client-side encryption. Removing it would change the product users signed up for.

Architecture promise

Even under a valid legal order, we can only produce what we possess: ciphertext. See our Terms →

Proof over promises

A system where even ShieldFive cannot read your files.

We cannot decrypt your files

Encryption happens before upload. Our servers receive ciphertext and do not receive the key needed to reverse it.

No recovery backdoor

If you lose your password or recovery phrase, we cannot reset our way into your files. That is the tradeoff that makes zero-knowledge real.

Breaches expose ciphertext

A server breach should not reveal readable files, because readable files are not what ShieldFive stores.

Create your private vault

Start with 20 GB free and test the workflow yourself.

Why it matters

No plaintext.
No training data.

// client encrypts before upload

// server stores ciphertext only

// ShieldFive cannot read your files

That's not a slogan. That's the architecture.

Access control

Share files that only open in the right country.

Set a country allowlist on any shared link. A confidential document shared with your Paris office won't open in Singapore. A client file stays within the EU. Access control that follows jurisdiction — not just a password.

Combine with expiry dates and download caps. Every shared link is zero-knowledge — recipients decrypt on their device only. We never see the contents of what you share.

// Share link · active restrictions

Allowed countries

DEFRNL+ EU

Expires

7 days

Downloads

5 max

Encrypted

E2E ✓

Access log

→ SG · blocked · not in allowlist

→ FR · granted · decrypting on device

→ DE · granted · decrypting on device

Built seriously

Photo of Cho, founder of ShieldFive

Cho Garcia

Founder

Built by a security-focused engineer because private files should not depend on corporate promises.

Zero-knowledge architecture · Client-side encryption · EU-hosted storage

Design commitments

Readable file accessNot held by ShieldFive
AI training materialNo plaintext available
Recovery backdoorNone
Business modelPrivate storage plans

Use cases

For files your provider should not read.

Legal

Contracts, case notes, and privileged client material.

Finance

Tax records, payroll files, invoices, and private balances.

Creative work

Drafts, assets, pitch decks, and unreleased project files.

Personal

IDs, family photos, backups, health records, and private archives.

Create your private vault

Private storage for work files, personal records, and anything you want kept out of training sets.

Pricing

Pay for storage. Never for your privacy.

Start free. Upgrade when you need more private storage.

Start free. Keep your first files private.

Use 20 GB private storage with no card required. Upgrade when you need more room.

Starter

For a focused private vault you control.

€2.50/mo€2.99/mo
Save 16.4%€29.99 Billed yearly

500 GB private storage

  • Encrypted storage for core documents
  • Secure links with limits
  • Email support
Most popular

Shield+

Serious private storage for everyday files.

€6.67/mo€7.99/mo
Save 16.6%€79.99 Billed yearly

2 TB private storage

  • 2 TB for active files and media
  • Advanced sharing controls
  • Priority support

Pro

For larger archives, client work, and private backups.

€12.50/mo€14.99/mo
Save 16.6%€149.99 Billed yearly

5 TB private storage

  • 5 TB for professional files
  • Brandable share links
  • Priority support

FAQ

The questions worth asking.

Direct answers about access, AI exposure, breaches, recovery, metadata, and provider differences.

Start private

Stop your files from becoming
training data.

Even ShieldFive cannot read them. Encrypted before upload.

Create your private vault — free

20 GB free · No credit card · Zero-knowledge encryption · EU storage