What is Proton Drive for?
Privacy-focused cloud storage with end-to-end, zero-knowledge encryption so the provider cannot read your files.
Proton Drive and Citadel do different jobs.
Proton Drive keeps the key with you. Citadel changes what is stored so a key is not the deciding factor.
What is Citadel for?
Protecting and archiving high-value information: board papers, IP, legal files, financial records, source code and private keys. It is a vault, not a workspace.
Do you need both?
Usually, yes. Most organisations keep Proton Drive for everyday work and move their crown-jewel data into Citadel, where there is no sharing surface at all.
Every Citadel subscription protects more than storage.
Citadel is priced for the people who use it and the work they do. The service connects identity, networking, transport, protected data, recovery and business continuity in one architecture.
Identity
Quantum-Secure® authentication designed to reduce dependence on traditional key-based access.
Network
Quantum-Secure® private networking extends protection beyond the storage environment.
Transport
ParticleMesh™ protects data as it moves between people, applications, clouds and infrastructure.
Data
Secured2 protection is applied to the data itself, beyond conventional encryption at rest.
Resilience
Multi-location redundancy, recovery and business continuity reduce dependence on any single system.
Risk
Eligible deployments can include contractual cyber-risk indemnification backed by a Lloyd's of London insurance policy.*
* Insurance, indemnification, coverage limits, exclusions, eligibility and availability are subject to the applicable policy and contractual terms.
An honest comparison.
Proton Drive is a capable product and we are not going to pretend otherwise. It is designed for productivity, and it is good at it.
Citadel is designed for containment. It has no sharing, no links, no guests and no sync client, because every one of those is a route out. Those absences would be flaws in a collaboration tool. In a vault they are the point.
Where the protection differs.
Mainstream platforms protect data with encryption and access controls: an algorithm, a key and a permission model. That is a reasonable design, and it rests on the key staying secret.
Citadel adds Secured2's physics-based Quantum-Secure® protection. Files are reduced, separated into fragments with no independent meaning, and distributed, so no single location holds a complete, readable file.
Proton Drive and Citadel side by side
| How they compare | |
|---|---|
| Protection model | Proton Drive: zero-knowledge encryption. Citadel: keyless, physics-based reduction, separation and distribution. |
| Single point of failure | Proton Drive: your key. Citadel: no master key reconstructs a file on its own. |
| Harvest now, decrypt later | Proton Drive: ciphertext could be stored for future attack. Citadel: fragments carry no independent meaning. |
| Sharing | Proton Drive: available. Citadel: none by design. |
| Audience | Proton Drive: privacy-conscious individuals and teams. Citadel: organisations protecting crown-jewel data. |
Questions people ask
- Is zero-knowledge encryption not enough?
- It is a genuinely strong model, and it still concentrates everything in one secret. Citadel removes that dependency.
- Is Citadel privacy-focused too?
- Yes. There is no sharing surface, activity is private to your account, and no location holds a readable file.
- Which should I choose?
- If you need private everyday storage, Proton Drive is a fine choice. If you are protecting information whose exposure would be material, use a vault.
Keep reading
Keep working where you work. Vault what you cannot lose.
Citadel sits alongside the tools your teams already use, and takes responsibility for the files that must never leak.