What is ShieldFive?

Zero-Knowledge Encryption Explained

Traditional cloud storage providers can access your files. ShieldFive is different:

• Your files are encrypted in your browser before upload using a post-quantum hybrid suite (ML-KEM-1024 + XChaCha20-Poly1305)

• Only you can decrypt file contents - files are encrypted before upload and we store only ciphertext, and shared-link passwords are verified server-side with hashed storage

• No keys on our side - we never hold the keys to your files, so there is no plaintext for employees to access

This is called "zero-knowledge" because we have zero knowledge of what you store.

How ShieldFive Works

1. Unlock: Sign in with your email and master password. Your master password is stretched with Argon2id to derive your vault key in the browser.

2. Encrypt: Each file you upload is encrypted in the browser under a fresh per-file key, which is then wrapped under your vault key.

3. Store: Only the ciphertext and wrapped key reach our servers.

4. Share: Create share links with optional share password, expiration, and download cap.

5. Download: Files decrypt in your browser as long as your vault is unlocked.

Key Features

• Client-Side Encryption: All encryption happens in your browser

• Strong Cryptography: Post-quantum hybrid encryption (ML-KEM-1024 + XChaCha20-Poly1305) with per-file random keys, wrapped under a vault key derived from your master password with Argon2id

• Zero-Knowledge: We store file contents only as ciphertext, never hold your keys, and do not store share-link passwords in plaintext

• Secure Sharing: Share with expiration, download limits, and country restrictions

• File Organization: Encrypted folders and search by file name. Names are encrypted, so search runs on your device and covers names in your open session only, not file contents

• Large Files: Chunked uploads, with the per-file ceiling set by the in-browser upload flow we are still polishing (currently below the storage bucket's 500 GiB limit) rather than by your plan

• No Account Required for Recipients: Anyone can download shared files

Who Should Use ShieldFive?

ShieldFive is perfect for anyone who values privacy:

• Individuals: Store personal documents, photos, and backups privately

• Professionals: Protect client data, contracts, and sensitive business files

• Healthcare: Encrypt sensitive records client-side before they leave your device. (ShieldFive does not currently offer a HIPAA Business Associate Agreement.)

• Legal: Secure client files and case documents

• Journalists: Protect sources and sensitive research

• Anyone in regulated industries: Ensure compliance with data protection laws

Pricing Plans

ShieldFive offers flexible pricing to fit your needs:

• Free: 5 GB storage, perfect for getting started
• Shield: 1 TB from €6/month
• Shield+: 2 TB from €10/month
• Pro: 5 TB from €20/month

All plans include the same security and zero-knowledge encryption. Annual plans offer significant savings.

The Trade-Off: Security vs. Recovery

ShieldFive prioritizes your privacy above all else. This means:

• Strong by default: Files are encrypted in your browser before they leave your device.

• No backdoors: We hold no copy of your keys, so your files open only with your master password or recovery key.

• One fallback only: If you lose your master password, your recovery key is the only way back in. If you lose both, the data is unrecoverable.

This is by design. If we could recover your data, so could anyone who compelled or compromised us.

Getting Started

Ready to try ShieldFive?

1. Create a free account (just email and password)
2. Verify your email address
3. Review the quick onboarding checklist (recommended)
4. Upload your first encrypted file

Start with the free plan and upgrade anytime as your needs grow.

Questions or Support

Need help getting started or have questions about ShieldFive?

• Browse our comprehensive Help Center
• Check the FAQ for quick answers
• Contact support

We're here to help you protect your privacy.