Checked against Proton’s and Tresorit’s own pages on 23 October 2026. We make Beebeeb, a competitor. Where a sentence is our reading, or we could not read a source, we say so. We left out prices we could not read from the vendors’ pages.
Both are end-to-end encrypted, so encryption will not decide it
Proton says “no one, not even Proton, can access your files and folders or see their names without your permission”, and describes using OpenPGP with elliptic-curve cryptography (Curve25519) (Proton Drive security). Tresorit says it encrypts “every file and relevant file metadata on your devices with unique randomly generated encryption keys”, organised as “a tree of symmetric keys” (Tresorit security). The designs differ in detail; on the basic property, that the provider does not hold your keys, both claim the same thing. We have not audited either claim ourselves.
Open source and audits
- Proton: “we’ve made all our apps and encryption libraries open source.” It also says “Proton Drive has been audited by Securitum” (page undated; scope and date not stated). (Proton Drive security)
- Tresorit: its security page says it is “audited and certified by TÜV Rheinland” and lists ISO 27001:2022, and it says it signs HIPAA Business Associate Agreements. Tresorit’s own blog describes an Ernst & Young review of its security architecture (Tresorit blog). We found no statement about its client source code on its security page; as far as we could find it does not publish it (our reading). (Tresorit security)
Our reading: for someone who wants to check the code, Proton’s open source is a real difference. For a compliance officer who needs certificates and signed reports, Tresorit’s certifications are a real difference. Both can be true.
Jurisdiction and ownership
Proton calls itself “a Swiss corporation whose primary shareholder is the non-profit Proton Foundation based in Geneva, Switzerland” (Proton: about). Tresorit says it “handles data under Swiss privacy laws” (Tresorit security). Swiss Post’s 2021 announcement says Swiss Post took a majority stake in Tresorit and gives the holding company’s seat as Luxembourg, with branches including Zurich, Munich and Budapest (Swiss Post release (German)).
What follows from jurisdiction, for example how the US CLOUD Act or intelligence-sharing arrangements apply to each company, is a legal question we are not answering here. Anyone who needs a firm answer should ask a lawyer.
Plans
Proton Drive Plus is listed at $4.99 per month for 200 GB on monthly billing, and Proton Unlimited (500 GB plus Mail, Calendar, Pass and VPN) at $12.99 per month on monthly billing; annual prices were not readable when we checked, so see Proton’s pricing page. Proton advertises 5 GB of free storage. Tresorit’s personal page lists 1 TB for Personal Essential and 4 TB for Personal Pro, and its business plans are Professional, Business, Business Pro and Enterprise, priced per user. We could not read Tresorit’s prices from its pages, so see personal and business. Prices change, so use the vendors’ pages.
Our reading: Proton looks aimed at individuals with a suite of products; Tresorit is aimed at organisations that need admin tools and certifications.
A third option
Beebeeb encrypts files on your device with AES-256-GCM before upload and derives keys with Argon2id, in every plan. The apps (web, desktop, iOS and CLI) are open source and the server is not. We are an EU company and store files in the EU. There has been no independent security audit yet, so on audits Tresorit and Proton are ahead of us. We cannot recover your files if you lose both your password and recovery phrase. There is no free plan, only a free trial. Compare prices in our dated price table and read the side-by-sides: Beebeeb vs Proton Drive and Beebeeb vs Tresorit.
Which one fits you (our reading)
- You want open-source clients and a suite of products: Proton Drive.
- You are an organisation that needs certifications and admin controls: Tresorit.
- You want open-source apps, EU jurisdiction and a single-purpose storage product, and can accept no audit yet: Beebeeb.
Common questions
Is Proton Drive end-to-end encrypted? Proton says no one, not even Proton, can access your files and folders or see their names without your permission.
Is Tresorit open source? We found no statement that its clients are open source and, as far as we could find, it does not publish them. Proton says its apps and encryption libraries are open source.
Who owns Tresorit? Swiss Post announced in 2021 that it took a majority stake.