Both are real zero-knowledge — so encryption won't decide it
Proton Drive and Tresorit are the two encrypted-storage incumbents most privacy buyers end up choosing between, and both deliver genuine end-to-end encryption: the provider holds ciphertext, not your keys. So the row everyone expects to settle the fight — encryption strength — is a tie. What actually decides it is whether you can read the source, where the company is legally bound, who owns it, and what you pay. Here's the head-to-head, fairly.
Encryption: a draw on the part that matters
Both providers are zero-knowledge by design. Files are encrypted on your device, and neither company can read the contents. The implementations differ in the plumbing. Proton Drive uses AES-256 for file data and RSA to wrap keys, and it encrypts filenames and folder structure, not just contents. Tresorit uses AES-256 end-to-end with its own key hierarchy that external cryptographers have examined. If your bar is "the provider must be mathematically unable to read my files," both clear it. Anyone selling you one over the other on cipher strength alone is selling marketing, not engineering.
Open source: Proton wins this one outright
Here is a real, checkable difference. Proton publishes its client apps on GitHub, and those clients have been independently audited — by Securitum, among others. You, or a researcher you trust, can read the code that does the encrypting before you believe the claim.
Tresorit's clients are closed source. The company commissions external audits and pentests instead — Ernst & Young, TÜV Rheinland, an ETH Zürich cryptographic review, ISO 27001 certification. That is a serious assurance posture. But it is "trust our auditors," not "read the code yourself." For a buyer who self-selects on verifiability, that gap is the whole decision. For a compliance officer who needs a signed report and a certificate to file, Tresorit's paper trail is the stronger artifact. Both can be true at once.
Jurisdiction: Swiss vs Swiss, with an ownership footnote
Both companies are Swiss, which keeps them outside the US CLOUD Act and the Five/Nine/Fourteen Eyes arrangements. Switzerland's FADP carries no blanket data-retention mandate, and content access requires a Swiss warrant. On paper this row is a draw too.
Two things belong in the footnotes. Tresorit's R&D sits in Budapest — an EU member, but a different legal environment from the Swiss HQ. And since 2021 Tresorit has been owned by Swiss Post, the state-owned postal operator, which is now its sole shareholder. State backing reads as stability to some buyers and as a thing to weigh to others; either way, it is not an independent company, and you should know that. Proton, by contrast, is majority-owned by the Proton Foundation, a Swiss non-profit. Neither structure is disqualifying. They are simply different, and a comparison that hides the ownership isn't honest.
Price: not close, and it depends what you're buying
Proton Drive is far cheaper for individuals. The free tier runs up to 5 GB once you complete a short onboarding. Drive Plus is $4.99/month billed monthly for 200 GB, dropping to about $3.99/month on an annual term. Proton Unlimited bundles 500 GB with Mail, VPN and a password manager for $9.99/month annual — that suite is the real value if you want the whole stack rather than just storage.
Tresorit is built and priced as a business tool. There's a free 3 GB Basic plan, but paid personal tiers open at $13.99/month for 1 TB (Personal Essential) and run to $33.99/month for 4 TB (Personal Pro). Business Standard lands around $18/user/month. You are paying for the admin console, audit logs, granular permissions, Microsoft 365 integration, and certifications like a HIPAA BAA and SOC 2 Type II — genuinely useful for a regulated team, overkill if you just want private storage for yourself. The honest summary: Proton is the better-value individual pick and the only one of the two with open, auditable clients; Tresorit is the stronger fit for a compliance-driven organisation that needs the certifications and admin tooling and will pay for them.
The third option: open-source clients, German jurisdiction
If you are cross-shopping these two, you are optimising for verifiable privacy — which is exactly why a third name belongs in the comparison. Beebeeb is zero-knowledge on every tier, no exceptions, and its product clients — the web app, the CLI, and the core crypto library — are open source like Proton's, with native mobile and desktop apps coming. The stack is AES-256-GCM for file data, Argon2id for key derivation, X25519 for sealing shares, and OPAQUE so your passphrase never reaches the server. Keys are zeroized from memory after use.
The caveats are stated plainly. Beebeeb's jurisdiction is German, not Swiss — data sits on dedicated servers in Falkenstein, Germany, operated by a Dutch-incorporated company, entirely outside US ownership. An independent audit is planned and the findings will be published; we have not been audited yet, and Tresorit's certification stack is more mature today. The clients are open; the server is not. Pricing is flat per terabyte: Starter €1.99/month for 100 GB, Basic €3.99/month for 200 GB, Pro €10.99/month for 1 TB, scaling to 99 TB self-serve with a custom quote beyond that — never "unlimited," because that word is a lie everyone in this category tells.
Where Beebeeb lands between the two: Proton's open-source verifiability without the Swiss-only jurisdiction, and Tresorit's storage headroom without the closed clients or the premium personal pricing. If verifiable privacy is the axis you care about, all three deserve a look — see the full Beebeeb-versus-Tresorit breakdown and the per-terabyte pricing before you commit.
Which one fits you
- Cheapest private storage plus a full privacy suite — Proton Drive. Open clients, 500 GB with Mail and VPN for $9.99/month annual.
- A regulated organisation that needs certifications and admin controls — Tresorit. HIPAA BAA, SOC 2, ISO 27001, audit logs, at premium pricing.
- Open-source clients with EU jurisdiction and flat per-TB scaling — Beebeeb, with the honest caveat that the audit is planned, not done.
All three are real zero-knowledge. None of them can read your files. After that, the right answer is whichever tradeoff fits your situation — and now you can name every one of them before you pay.