Encrypted Cloud Storage Comparison: Which Provider Can't See Your Files?

Your "Cloud" Is Someone Else's Computer

Google Drive, Dropbox, OneDrive, and iCloud can all access your files. They encrypt data in transit and at rest, but they hold the keys. This means:

  • Employees can theoretically access your files
  • Government agencies with legal orders get full access
  • A data breach exposes your actual files, not just encrypted blobs
  • AI systems may scan your content (Google does this)

Zero-knowledge encrypted storage solves this, but most people don't use it.

Two Approaches to Encrypted Storage

  1. Native encrypted providers: Proton Drive, Tresorit, Sync.com: encryption built-in
  2. Encryption layer on existing storage: Cryptomator: add encryption to Dropbox/Google Drive

Both approaches work. Native providers are simpler; encryption layers are more flexible.

Quick Comparison Table

Provider Free Storage Paid Price Zero-Knowledge Our Rating
Proton Drive 2 GB (5 GB with bonus) €4.99/mo (200GB) Yes Best Overall
Tresorit 3 GB $11.99/mo (1 TB) Yes Best for Business
Sync.com 5 GB $8/mo (2TB) Yes Best Value
Cryptomator Free* €29.99 one-time (mobile full version) Yes Most Flexible
pCloud up to 10 GB $49.99/year (500GB) Extra ($) Good Alternative

*Cryptomator requires separate cloud storage (Dropbox, Google Drive, etc.)

Understanding Encryption Types

Standard Cloud Storage (Not Recommended for Sensitive Data)

  • Examples: Google Drive, Dropbox, OneDrive, iCloud
  • Encryption: TLS in transit, AES-256 at rest
  • Who has the keys: The provider
  • Can provider read your files: Yes
  • Government access: Full access with legal order

Zero-Knowledge Encryption (Recommended)

  • Examples: Proton Drive, Tresorit, Sync.com
  • Encryption: End-to-end, client-side
  • Who has the keys: Only you
  • Can provider read your files: No
  • Government access: Encrypted blobs only (useless without your key)

Detailed Provider Breakdown

Proton Drive: Best Overall

Why We Recommend It: Proton Drive integrates directly with ProtonMail, VPN, and Pass. Swiss jurisdiction with strong privacy laws. The same zero-knowledge approach that made ProtonMail popular applies to Drive.

Pricing

  • Free: 2 GB base storage, rising to 5 GB after you finish Proton's onboarding steps (add a file, create a share link, set a recovery method)
  • Drive Plus: €4.99/mo: 200 GB, file version history
  • Proton Unlimited: €12.99/mo: 500 GB, includes Mail, VPN, Pass
  • Proton Duo: €19.99/mo: 2 TB shared, 2 users
  • Proton Family: €29.99/mo: 3 TB shared, 6 users

Security Features

  • End-to-end encryption (files encrypted before leaving your device)
  • Zero-knowledge architecture (Proton cannot access your files)
  • Open source clients
  • Swiss jurisdiction (not 14 Eyes)
  • Encrypted file sharing with password protection
  • 30-day money-back guarantee

Additional Features

  • Online document and spreadsheet editor
  • Desktop sync clients (Windows, Mac; Linux is command-line only, no GUI sync client yet)
  • Mobile apps (iOS, Android)
  • File version history (paid plans)
  • Part of Proton ecosystem

Limitations

  • Smaller storage compared to mainstream providers
  • No Linux GUI sync client yet; a command-line tool shipped in June 2026
  • Less mature than competitors like Dropbox
  • Ecosystem lock-in if you use all Proton services
  • Advertised prices are often introductory: the discounted first term reverts to the standard rate at renewal
  • Proton stays legally Swiss but is moving most of its physical servers to the EU (Germany) and Norway over a proposed Swiss surveillance ordinance

Best for: Users who already use ProtonMail or want an all-in-one privacy ecosystem.

Read our full Proton Drive review.

Try Proton Drive →

Some links in this guide are affiliate links; see our affiliate disclosure for the full policy.

Tresorit: Best for Business

Why Consider It: Tresorit is the gold standard for business encrypted storage. GDPR, HIPAA, and ISO 27001 certified. Better collaboration and compliance features than competitors.

Pricing

  • Free: 3 GB storage, 500 MB file size limit
  • Personal Lite: 50 GB
  • Personal Essential: $11.99/mo (annual): 1 TB
  • Personal Pro: 4 TB, priority support
  • Business: min 3 users, 2 TB/user, team features
  • Business Pro: min 5 users, advanced admin controls
  • Enterprise: Custom pricing

Security Features

  • End-to-end encryption (AES-256)
  • Zero-knowledge architecture
  • Swiss jurisdiction
  • Client-side encryption before upload
  • Encrypted link sharing with expiration and password
  • Audit logs and compliance reporting

Business Features

  • Team management and user permissions
  • Remote wipe capability
  • Data residency controls
  • Active Directory integration
  • HIPAA BAA available
  • SOC 2 Type II certified

Limitations

  • More expensive than alternatives
  • Free tier is very limited (3 GB, 500 MB file limit)
  • Overkill for personal use
  • 14-day trial requires credit card

Best for: Businesses needing compliance (HIPAA, GDPR) and enterprise features.

Try Tresorit →

Sync.com: Best Value

Why Consider It: Sync.com offers the best price-to-storage ratio for zero-knowledge encryption. Canadian jurisdiction is better than US. Solid choice for users who just want encrypted storage without bells and whistles.

Pricing

  • Free: 5 GB storage
  • Solo Basic: $8/mo: 2 TB
  • Solo Professional: $20/mo: 6 TB
  • Teams 1TB: $6/user/mo: 1 TB/user
  • Teams 10TB: $15/user/mo (annual): 10 TB/user (min 3 users)

Security Features

  • End-to-end encryption (AES-256)
  • Zero-knowledge privacy
  • Canadian jurisdiction (Canada is a core Five Eyes member, within the 14 Eyes umbrella)
  • 2FA available
  • Encrypted sharing with passwords and expiration
  • Remote device wipe

Features

  • Generous free tier (5 GB)
  • Desktop sync (Windows, Mac)
  • Mobile apps
  • File versioning (unlimited on paid plans)
  • Vault for extra-sensitive files

Limitations

  • Canadian jurisdiction (Five Eyes member)
  • Less feature-rich than Tresorit for business
  • Interface is functional but dated
  • No Linux desktop client

Best for: Users wanting maximum storage per dollar with zero-knowledge encryption.

Try Sync.com →

Cryptomator: Most Flexible

Why Consider It: Cryptomator doesn't replace your cloud storage, it encrypts files before they reach it. Keep using Dropbox, Google Drive, or iCloud, but add a zero-knowledge encryption layer.

Pricing

  • Desktop: Free (Windows, Mac, Linux)
  • iOS/Android: Free (read-only); full version €29.99 one-time (often discounted)
  • Cryptomator Hub: Team pricing for enterprise

How It Works

  1. Create an encrypted "vault" in your existing cloud folder (Dropbox, Google Drive, etc.)
  2. Files placed in the vault are automatically encrypted with AES-256
  3. Your cloud provider sees only encrypted blobs with random names
  4. Only you can decrypt with your password

Security Features

  • AES-256 encryption
  • Open source (audited)
  • Client-side encryption only
  • Works with any WebDAV or cloud provider
  • No account required (no metadata to leak)
  • File names are also encrypted

Supported Providers

  • Dropbox
  • Google Drive
  • OneDrive
  • iCloud Drive
  • pCloud
  • Any WebDAV or S3 storage

Limitations

  • Requires separate cloud storage subscription
  • More technical setup than native providers
  • No web access to encrypted files
  • Collaboration is harder (everyone needs Cryptomator)
  • iOS app is limited

Best for: Users who want to keep existing cloud storage but add encryption. Maximum flexibility.

Try Cryptomator →

pCloud: Good Alternative (With Caveat)

Why Consider It: pCloud offers lifetime plans (one-time payment for storage) and good performance. However, zero-knowledge encryption costs extra, it's not included by default.

Pricing

  • Free: Up to 10 GB (base storage unlocked via setup steps; full 10 GB requires referrals)
  • Premium: $49.99/year or $199 lifetime: 500 GB
  • Premium Plus: $99.99/year or $399 lifetime: 2 TB
  • pCloud Crypto: +$49.99/year or +$150 lifetime: Zero-knowledge encryption

Security

  • TLS encryption in transit
  • AES-256 at rest
  • Zero-knowledge ONLY with pCloud Crypto add-on
  • Crypto folder is separate from regular storage

Limitations

  • Encryption costs extra (not included by default)
  • Swiss company but Luxembourg data centers
  • Only the "Crypto" folder is zero-knowledge
  • Mixed jurisdiction concerns

Best for: Users who want lifetime pricing and don't mind paying extra for encryption.

Full review, including the EU-vs-US region choice that matters more than most people realize: our pCloud review.

Try pCloud →

Feature Comparison

Feature Proton Drive Tresorit Sync.com Cryptomator
Zero-Knowledge Yes (all) Yes (all) Yes (all) Yes (all)
Open Source Yes No No Yes
Web Access Yes Yes Yes No
Desktop Sync Win/Mac Win/Mac/Linux Win/Mac Win/Mac/Linux
Mobile Apps iOS/Android iOS/Android iOS/Android iOS/Android
Collaboration Basic Advanced Basic None
Compliance GDPR GDPR/HIPAA/SOC2 GDPR N/A
Jurisdiction Switzerland Switzerland Canada Germany

Use Case Recommendations

Personal Use: Proton Drive

Free tier up to 5 GB, integrates with ProtonMail. Swiss jurisdiction. Simple setup.

Get Proton Drive →

Business/Healthcare: Tresorit

HIPAA compliant, enterprise features, audit logs. Worth the premium for regulated industries.

Get Tresorit →

Maximum Storage: Sync.com

2TB for $8/month with zero-knowledge. Best value if you need lots of space.

Get Sync.com →

Keep Existing Provider: Cryptomator

Free encryption layer for Dropbox, Google Drive, iCloud. Maximum flexibility.

Get Cryptomator →

What About Google Drive / Dropbox / iCloud?

Mainstream Providers Are NOT Zero-Knowledge

These providers encrypt your data, but they hold the keys:

  • Google Drive: Google can read your files. AI scans documents. Government access available.
  • Dropbox: Dropbox employees can access files. Has cooperated with government requests.
  • iCloud: Apple holds keys for most data. Advanced Data Protection (opt-in) is zero-knowledge but disabled by default.
  • OneDrive: Microsoft holds keys. Scans for illegal content.

If you must use these: Use Cryptomator to add a zero-knowledge layer on top.

Migration Tips

Moving from Google Drive/Dropbox

  1. Download all your data using Google Takeout or Dropbox export
  2. Set up your encrypted provider and verify it works
  3. Upload files to new provider (may take days for large libraries)
  4. Verify all files transferred before deleting from old provider
  5. Update apps that were linked to old storage
  6. Delete from old provider only after verification

Gradual Migration (Recommended)

  • Use encrypted storage for new sensitive files immediately
  • Migrate existing sensitive files first
  • Keep non-sensitive files on existing provider if convenient
  • Use Cryptomator if you want encryption on your current provider

The Bottom Line

Summary

If privacy matters, use zero-knowledge encrypted storage.

  • Best overall: Proton Drive: Swiss jurisdiction, open source, part of privacy ecosystem
  • Best for business: Tresorit: HIPAA/SOC2 compliant, enterprise features
  • Best value: Sync.com: Most storage per dollar with zero-knowledge
  • Most flexible: Cryptomator: Add encryption to any cloud provider

Google Drive and Dropbox are convenient, but they can access your files. For truly private storage, zero-knowledge encryption is non-negotiable.

Related Guides

References

  1. Proton Drive Pricing
  2. Tresorit Pricing
  3. Sync.com Pricing
  4. Cryptomator Official Site
  5. Cloudwards - Cryptomator Review