Cloud storage decision
Proton Drive Plus
A small team can build a usable zero-knowledge file upload/share service, but reproducing Proton Drive Plus' cross-platform apps, audited privacy guarantees, and global infrastructure is expensive; keep paying for full feature/scale unless you only need a narrow self-hosted workflow.
Visit website↗Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need — the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship.
What a replacement has to do
- Provide zero-knowledge cloud storage for a single user: upload encrypted files, download/decrypt, and create shareable encrypted links with access controls.
What it still won’t have
- Cross-platform native apps and background sync (desktop/mobile)
- Large-scale global infrastructure and high-availability servers
- Independent security audits and established trust branding
- Integrated Proton ecosystem features (VPN, Mail, Pass, Lumo AI)
- Regulatory assurances from Swiss hosting and enterprise compliance programs
What remains hard
- Infrastructure at scale
2000+ servers in 10+ countries
- Brand trust
Trusted by over 100 million users and organizations
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 2 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal self-hosted zero-knowledge cloud storage web app using: React front-end, Node.js/Express API, Postgres for metadata, and S3-compatible object storage (MinIO) for file blobs. Implement client-side AES-GCM or Web Crypto-based encryption for file uploads and decryption on downloads; store only encrypted blobs and non-sensitive metadata in Postgres. Include endpoints to: upload encrypted chunks, assemble files, list files and versions, generate expiring/password-protected share links, and revoke links. Provide a basic React UI for file/folder browsing, upload (chunked), download, and link management. Out of scope: native mobile/desktop sync clients, federated storage, enterprise compliance certifications, and third-party integrations. Include input validation, error handling, logging, and automated tests for encryption, upload/download, and link workflows.
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 5 cited sources+3
- 3/3 assessment runs agreed+4
- Hard moats found in the evidence-3
- Evidence score61
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time — so the same evidence always produces the same number.
How scoring works →Cited sources · 5
Every page the run actually retrieved.
- official productProton home
- official pricingProton Pricing
- official docsProton Drive docs
- open sourcehudikhq/hoodik
- open sourcehaiwen/seafile
Integrity checks
What held up, and what did not.
