The short answer: Tresorit is one of the most established zero-knowledge storage products, with ISO 27001 and Common Criteria certification, and it is the right choice when procurement needs those. People look for a Tresorit alternative when they need something lighter for a small team, a lower price to start, an upload link clients can use without an account, or a replacement for the discontinued Boxcryptor. ShieldFive covers those cases and gives up Tresorit's certifications, maturity and admin depth.
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 residency in twelve storage regions (including Germany, Switzerland, France, Ireland, the Netherlands, the UK, the US, Canada, Singapore, the UAE and Brazil), selectable per user. 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. If you are still comparing more than these two vendors, our comparison of ten zero-knowledge cloud storage providers covers the wider field.
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.
- Price and fit for a small practice. Tresorit is built and priced for organisations with admin and compliance requirements. A sole practitioner who mainly needs encrypted storage and a way for clients to send documents may not need that depth.
- Replacing Boxcryptor. Boxcryptor encrypted files inside Dropbox, Google Drive or OneDrive. Dropbox acquired its technology in November 2022, new personal and free accounts were closed in early 2023, and Boxcryptor's operator ceased operations at the end of 2025. Tresorit is a common destination; a zero-knowledge store that encrypts everything by default does the same job without a separate encryption layer.
None of these are knocks on Tresorit. They are requirements Tresorit does not optimize for today, and where a different product can.
ShieldFive: what it does, and its limits
ShieldFive encrypts every file, and its name, on your device before upload, on every plan including the free one. We store only ciphertext and never hold your keys. Sign-in sends a key derived from your password in the browser, not the password itself.
Web uploads default to post-quantum hybrid encryption (ML-KEM-1024 with XChaCha20-Poly1305), with AES-256-GCM as a fallback. The Android app, in Google Play testing and not yet a public release, uses the same format. There is no iOS app or desktop sync client yet. For firms, a document request lets a client upload files to you through one link, without creating an account.
The limits: we serve the web app's code, so the guarantee holds for the code you are served; file sizes and timestamps are not encrypted; the crypto core is open source (Apache-2.0) but the apps are not; and no external security audit has been completed. Review the security model and current plans before choosing.
ShieldFive vs Tresorit at a glance
| Capability | ShieldFive | Tresorit |
|---|---|---|
| Post-quantum on stored files | Hybrid default on web and Android, AES-GCM fallback | In progress — hybrid ML-KEM-1024 named in a February 2026 post, not yet live |
| Jurisdiction | EU | Switzerland (Swiss Post); 12 storage regions, selectable per user |
| Zero-knowledge / end-to-end | Yes — every file and filename, on every plan | Yes |
| Product scope | Focused encrypted storage | Established business suite (admin controls, eDiscovery) |
Comparison reflects each vendor's public documentation as of 22 September 2026 and is updated as products change.
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-user data residency across twelve storage regions. 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 you want every file encrypted on your device by default without picking a special folder, need clients to upload to you without an account, and can accept a younger product with no external audit yet and no iOS or desktop sync app. Test it with files you can afford to lose first.
Try it
The free plan is 5 GB with no card. Upload a few test files, share one with an expiry, revoke it, and check recovery before moving anything that matters.
This comparison reflects each vendor's public documentation as of 22 September 2026; the Boxcryptor timeline was checked on 4 October 2026. It will be updated as the products change.