Best Encrypted Cloud Storage 2026
Quick verdict
- Best overall: Proton Drive — full privacy ecosystem (Mail, VPN, Pass), Swiss jurisdiction, open-source, 5 GB free with zero-knowledge encryption on all files.
- Best for compliance: Tresorit — GDPR, HIPAA, ISO 27001 certified, largely unaffected by ETH Zurich vulnerability study, Swiss Post backing.
- Best value per TB: Sync.com — 1 TB for $5/mo with zero-knowledge on the entire account by default, Canadian jurisdiction.
- Best lifetime deal: Icedrive — 2 TB for $389 one-time, virtual drive mount UX. But ETH Zurich found vulnerabilities they refused to patch.
- Best budget E2EE: Internxt — 2 TB for $7.49/mo, EU-based, open-source, anonymous sign-up. Performance issues reported.
Comparison table
| Provider | Free tier | 1 TB price | Encryption | Jurisdiction | Trustpilot |
|---|---|---|---|---|---|
| Proton Drive | 5 GB | $9.99/mo (Unlimited) | Zero-knowledge E2EE | Switzerland | 4.3 |
| Tresorit | 14-day trial | $11.99/mo | Zero-knowledge E2EE | Switzerland | 4.4 |
| Sync.com | 5 GB | $5/mo | Zero-knowledge E2EE | Canada | 4.2 |
| Icedrive | 10 GB | $6.67/mo | ZK (Encrypted folder only) | UK | 4.3 |
| Internxt | 1 GB | $7.49/mo (2 TB) | Zero-knowledge E2EE | Spain | 3.8 |
Detailed reviews
Proton Drive
Best for: Proton ecosystem users wanting integrated encrypted storage Our top pick. The only major encrypted cloud storage backed by a full privacy ecosystem — Proton Mail, VPN, Pass, and Calendar under one subscription. Swiss jurisdiction, open-source clients, and zero-knowledge encryption on all files and metadata. Still maturing (launched 2022) but backed by Proton's strong brand trust.
Pros
- Full privacy ecosystem (Mail, VPN, Pass, Calendar)
- Swiss jurisdiction with constitutional privacy protections
- Open-source clients with community audit
- 5 GB free tier with full E2EE
- Encrypted photo backup
Cons
- Relatively new storage product (2022 launch)
- No desktop sync for Linux (CLI only)
- Storage caps lower than competitors at similar prices
- No real-time collaboration features
Pricing: Free 5 GB · $3.99/mo Drive Plus (200 GB) · $9.99/mo Unlimited (500 GB)
Try Proton Drive free → 
Tresorit
Best for: Regulated industries needing compliance certifications The compliance champion. Only provider largely unaffected by the ETH Zurich 2024 vulnerability study. GDPR, HIPAA, and ISO 27001 certified with Swiss Post backing. Best for regulated industries (legal, healthcare, finance) despite the premium price tag.
Pros
- Strongest cryptographic design (ETH Zurich vindicated)
- GDPR, HIPAA, ISO 27001 compliance certifications
- Swiss Post backing
- Desktop sync on Windows, macOS, and Linux
- DRM for shared files
Cons
- Most expensive personal plan per TB
- No free tier (14-day trial only)
- Limited collaboration features
- Slower UI responsiveness reported
Pricing: $11.99/mo Personal (1 TB) · $27.49/mo Professional (4 TB)
Try Tresorit → 
Sync.com
Best for: Budget-conscious users wanting full-account zero-knowledge encryption Best value for zero-knowledge storage. E2EE applied to your entire account by default — not just a special folder. 1 TB for $5/mo is the best price-per-TB among true zero-knowledge providers. However, the ETH Zurich 2024 study found a key-injection vulnerability.
Pros
- Zero-knowledge encryption on entire account by default
- Best value: 1 TB for $5/mo
- HIPAA compliant on business plans
- 5 GB free tier with full E2EE
- Unlimited file versioning (180-365 days)
Cons
- ETH Zurich 2024 found key-injection vulnerability
- Slower upload/download speeds
- No Linux desktop client
- Interface feels dated
Pricing: Free 5 GB · $5/mo Standard (1 TB) · $8/mo Plus (2 TB) · $15/mo Advanced (6 TB)
Try Sync.com free → 
Icedrive
Best for: Lifetime-deal seekers who accept the security trade-offs Best lifetime deal with a clean, modern UI and virtual drive mount. Generous 10 GB free tier. However, zero-knowledge encryption is limited to a dedicated Encrypted folder (not all files), and they refused to patch vulnerabilities found in the ETH Zurich 2024 study.
Pros
- Lifetime plans eliminate recurring costs ($389 for 2 TB)
- Virtual drive mount appears as local drive
- 10 GB free tier
- Clean, modern UI with fast speeds
- Cross-platform including Linux
Cons
- Zero-knowledge limited to Encrypted folder only
- ETH Zurich 2024: refused to patch vulnerabilities
- No file versioning
- No 2FA on free plan
Pricing: Free 10 GB · $4.17/mo Pro I (150 GB) · $6.67/mo Pro II (1 TB) · $389 Lifetime (2 TB)
Try Icedrive free → 
Internxt
Best for: Budget EU users wanting open-source zero-knowledge storage Most affordable per-TB zero-knowledge storage with EU jurisdiction and open-source clients. Anonymous account creation is a privacy plus. But users report slow upload speeds, buggy web interface, and reliability issues that undermine the value proposition.
Pros
- Most affordable per-TB pricing in zero-knowledge space
- Anonymous account creation (no email required)
- EU-based with GDPR-native compliance
- Open-source clients
- Securitum security audit
Cons
- Slow upload speeds (below 5 MB/s reported)
- Buggy web interface with sync failures
- Very small free tier (1 GB)
- No file versioning
Pricing: Free 1 GB · $4.49/mo (200 GB) · $7.49/mo (2 TB) · $16.99/mo (10 TB)
Try Internxt free → ETH Zurich vulnerability context
In October 2024, ETH Zurich published “End-to-End Encrypted Cloud Storage in the Wild: A Broken Ecosystem,” which tested the cryptographic implementations of major providers:
- Tresorit: Largely vindicated. No critical vulnerabilities found.
- Sync.com: Key-injection vulnerability — server could force attacker-controlled keys.
- pCloud: Key-injection and chunk authentication vulnerabilities found.
- Icedrive: Vulnerabilities found. Icedrive chose NOT to address them.
- Proton Drive: Not included in the study (newer product), but uses proven Proton cryptography.
This research is a critical input to our recommendations. We weight post-audit response as heavily as the findings themselves.
Related guides
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- Best Encrypted Email — Keep your communications private
- Best Password Manager — Secure your accounts
- Best VPN for Privacy — Protect your browsing from surveillance
Frequently Asked Questions
What is zero-knowledge cloud storage?
Zero-knowledge means the provider cannot read your files, even if compelled by law enforcement. Files are encrypted on your device before upload, and only you hold the decryption key. Proton Drive, Tresorit, and Sync.com apply this to all files by default.
Is encrypted cloud storage slower than regular cloud storage?
Slightly. Client-side encryption adds processing overhead during upload and download. In practice, Proton Drive and Icedrive are comparable to mainstream providers for typical file sizes. Large file uploads (10+ GB) may be noticeably slower on Internxt and Filen.
Are lifetime cloud storage plans a good deal?
They can be, but carry risk. Icedrive and pCloud offer lifetime plans ($199-$399 for 2 TB), which pay for themselves in 3-4 years. The risk is the company shutting down or degrading service. pCloud (2013) has the longest track record among lifetime plan providers.
Did the ETH Zurich study find vulnerabilities in encrypted cloud storage?
Yes. The October 2024 ETH Zurich study found severe vulnerabilities in Sync.com, pCloud, Icedrive, and Seafile. Tresorit was largely vindicated. Icedrive refused to patch the issues. This is a critical consideration when choosing a provider.
Which encrypted cloud storage has the best free tier?
MEGA offers 20 GB free (largest), but uses weaker AES-128 encryption. Icedrive and pCloud offer 10 GB free. Proton Drive and Sync.com offer 5 GB free with full zero-knowledge encryption. Internxt offers only 1 GB free.