What Tresorit does well
Tresorit is a serious, mature product, and it is worth saying so plainly. It applies zero-knowledge encryption consistently across its entire platform as a default design principle: files are encrypted on your device before upload, the keys stay in your control, and Tresorit states that "not even Tresorit can access or read your content." That is the right architecture, and Tresorit has built its whole product around it rather than bolting it on.
It also carries weight that a newer product cannot. Tresorit was founded in 2011 and is now part of Swiss Post's digital business services, handling data under Swiss privacy law, with data stored by default in European or Swiss data centres and region selection available on business and enterprise plans. And it has the certifications to match: ISO/IEC 27001:2022, and a publicly announced Common Criteria EAL4+ certification. If you want an established, certified, enterprise-grade zero-knowledge product with a Swiss parent, Tresorit is a strong default.
The rest of this page is about the specific cases where a different set of tradeoffs fits better.
Why people look for an alternative
People who already trust Tresorit still come looking for an alternative, usually for one of a few concrete reasons:
- Post-quantum protection that is already the default. Tresorit has begun integrating post-quantum cryptography, but describes it as a gradual, in-progress migration. Some buyers want post-quantum encryption shipping on every upload today, not on a roadmap.
- An open, checkable crypto core. They want to read the exact code that encrypts their files, rather than accept a description of a proprietary implementation.
- EU jurisdiction, not only EU data centres. Tresorit stores in the EU or Switzerland and is a Swiss company. For some buyers the requirement is specifically EU corporate jurisdiction.
None of these are knocks on Tresorit. They are requirements Tresorit does not optimize for today, and where a different product can.
Where ShieldFive differs
ShieldFive differs from Tresorit in a few specific, checkable ways. Both are zero-knowledge by default, so this section is about the narrower points where they diverge.
Post-quantum already shipping by default. ShieldFive defaults every new upload to a post-quantum hybrid suite: ML-KEM-1024 (FIPS 203) combined with a classical cipher, so a break in either component alone does not expose the file. Tresorit, in a blog post dated 26 November 2025, says it is "gradually integrating" post-quantum cryptography using a hybrid approach; its post names the same NIST standards ShieldFive relies on, including ML-KEM-1024, with ECC-based encryption staying on as the classical half of the hybrid. So the difference here is not the target algorithm — both point at ML-KEM-1024 — but the timing: Tresorit describes an in-progress migration, while ShieldFive's post-quantum protection is the shipping default on every upload today.
This matters because of "harvest now, decrypt later." An adversary can copy encrypted files today and simply wait — storing the ciphertext until a quantum computer capable of breaking classical key exchange exists, then decrypting it retroactively. Files with a long confidentiality lifetime — legal records, medical data, source material, trade secrets — are exposed to that strategy the moment they are uploaded. Post-quantum encryption at upload time is the only point where you can close that window. You cannot retrofit it onto data an adversary already holds, which is why "already the default" and "being integrated" are not the same thing for files uploaded today.
An open-source crypto core. ShieldFive's encryption core is published under Apache-2.0 — the same code that runs in your browser, with a public specification and test vectors. You can diff the published source against what ships. Tresorit publishes a list of the third-party open-source libraries it builds on, such as OpenSSL, Crypto++, SQLite and libcurl, but — unlike those dependencies — does not appear to publish the source of its own client or encryption implementation. The point is not that open source is automatically more secure, but that with ShieldFive you do not have to take the encryption on description — you can read it.
EU jurisdiction. ShieldFive operates under EU jurisdiction and stores encrypted data in the EU by default. Tresorit is a Swiss company, part of Swiss Post, and stores data by default in European or Swiss data centres, with region selection on its business and enterprise plans. This is a narrow distinction, and an honest one: Swiss privacy law is strong, and Tresorit can already keep your data in the EU. If your requirement is specifically EU corporate jurisdiction, or EU storage as the default without selecting a region, ShieldFive answers that directly. If a Swiss company with EU data centres meets your requirement, this is not an advantage.
No AI training and no scanning. Like Tresorit, ShieldFive does not train models on your files and does not scan their contents — because both are zero-knowledge, the server only ever holds ciphertext. This is a property the two architectures share, not a point of separation; we mention it because it is a common question.
Pricing. ShieldFive's free tier is 20 GB with no card required. Shield+ is 2 TB at €2.75/month billed every three years, €6.67/month billed annually, or €7.99 billed monthly. Tresorit is positioned largely as a business and enterprise product with its own plans; compare against them directly on current terms.
Where Tresorit is ahead, honestly
A fair comparison has to run both ways, so here is where Tresorit is the stronger choice today.
Certifications. This is the clearest one. Tresorit holds ISO/IEC 27001:2022 certification and has publicly announced Common Criteria EAL4+ certification for its Core Interface component. ShieldFive's crypto core is open and readable, but it has not yet completed an external audit, and it holds no comparable formal certification — those are planned, not done. If certifications are a procurement requirement, Tresorit is straightforwardly ahead, and it would be wrong to imply otherwise.
Maturity and enterprise depth. Tresorit has shipped since 2011, is backed by Swiss Post, and offers enterprise features such as per-team data-residency region selection across many countries. ShieldFive is new and focused. For a large organisation with complex residency and administration needs, Tresorit covers more ground.
If you need a certified, established, enterprise-grade zero-knowledge product today, Tresorit is the stronger pick.
Which one fits you
Tresorit fits you if you want a mature, certified, enterprise-grade zero-knowledge product with a Swiss parent and flexible data-residency regions, and ISO 27001 plus Common Criteria EAL4+ is the kind of assurance your procurement needs.
ShieldFive fits you if your priorities are post-quantum protection already shipping by default on every upload, an open crypto core you can read and verify, and EU jurisdiction with EU storage as the default — with the honest caveat that ShieldFive's external audit and certifications are still ahead of it, where Tresorit's are already in hand.
Try it
The way to evaluate this is in practice. ShieldFive's free tier is 20 GB with no card, enough to test the workflow with non-critical files first — upload, share with expiry, revoke — before moving anything that matters. Migration is a risk-tiering decision: move the highest-sensitivity files first, the ones where post-quantum-by-default or EU jurisdiction actually changes the exposure, and leave the rest wherever it already works.
This comparison reflects each vendor's public documentation as of 2026-06-17 and will be updated as the products change.