You are comparing document platforms. Each one says it is encrypted. That word feels like a finish line. It is really a starting point.
The question that matters is simple. When your files sit on the vendor's servers, can the vendor read them? For most products the honest answer is yes. This guide helps you tell the difference and ask the right things.
What "encrypted" usually means on a datasheet
Most datasheets mean two things. Encryption at rest. Encryption in transit. Both are good. Neither one keeps your data secret from the vendor.
Encryption at rest means the files are scrambled while stored on disk. If someone steals the disk, the files look like noise. But the vendor holds the key. The vendor's software unlocks the files to show them to you, to index them, to run features. A staff member with the right access can do the same.
Encryption in transit means the connection between you and the server is protected, usually with TLS. It stops someone listening on the network. It says nothing about what happens once the data arrives.
End-to-end and zero-knowledge encryption work differently. Your files are sealed on your own device before they leave. The key lives with you, not the vendor. The vendor stores ciphertext and cannot open it. A breach of the vendor yields scrambled data, not your documents.
This is the line that splits the market. Most platforms sit on the at-rest side. A smaller group sits on the zero-knowledge side. If you only read our other guide on what zero-knowledge encryption is, the rest of this guide will feel familiar.
Six questions to ask any vendor
Send these to a vendor in writing. The answers, side by side, tell you more than any brochure.
1. Who holds the keys? If the vendor can decrypt your files without your password, the vendor holds the keys. Ask plainly. A clear answer is a good sign.
2. What does a breach actually yield? If attackers take the database, do they get readable documents or ciphertext? This is the question your board will ask after an incident.
3. Is e-signing inside or outside the encryption boundary? Many platforms send a document to a separate signing service. That service often reads the file in the clear. Tresorit eSign keeps signatures end-to-end encrypted. DocuSign manages the keys itself by default, with customer-managed keys only on a paid tier. Ask where signing happens.
4. What workflow runs on the encrypted data? Review, approval, versioning, comments. If these features need the vendor to read the file, the encryption is weaker than it looks.
5. Can you self-host? Some buyers, especially in government and healthcare, must keep data on their own infrastructure. Ask whether the platform runs on your servers or only in the vendor's cloud.
6. What does the audit trail record? Who opened, changed, shared and signed each document, and when. A signed, tamper-evident trail matters for disputes and for compliance.
An honest look at the options
No single product wins for everyone. Here is where the main options genuinely fit.
| Option | Genuine strength | Best fit |
|---|---|---|
| Tresorit | Mature, certified end-to-end encrypted storage with end-to-end encrypted eSign. | Teams wanting proven encrypted storage, sharing and signing in a managed cloud. |
| Proton Drive | End-to-end encrypted Docs and Sheets in a privacy-first suite. | Individuals and small teams who edit inside the vault but do not need native e-signing. |
| Sync.com | Zero-knowledge, end-to-end encrypted file storage on all files by default, easy to use. | Businesses that want simple encrypted file storage and sharing without extra workflow. |
| Nextcloud | Open source and self-hostable, with optional end-to-end encryption you control. | Teams with IT capacity who want full control and accept the setup effort. |
| Zeromatics Workspace | Zero-knowledge documents, workflow, e-signing and private hosting on one core. | Organisations that need the encrypted vault and the workflow and signing in one place, on their own infrastructure. |
If e-signing is part of your decision, our DocuSign alternative page goes deeper on that piece.
- "Encrypted" on a datasheet usually means at-rest and in-transit — the vendor can still read your files.
- Only end-to-end, zero-knowledge encryption means a vendor breach yields ciphertext, not documents.
- Always ask: who holds the keys, what a breach yields, and whether e-signing stays inside the boundary.
- Match the tool to the need — storage alone, or storage plus workflow and signing on your own servers.
When zero-knowledge matters most
Zero-knowledge is not always required. For low-risk internal files, at-rest encryption may be enough. The calculus changes when the documents are sensitive and the cost of exposure is high.
It matters most for legal files, health records, financial records, government work and anything under strict privacy law. In those cases you want the vendor to be unable to read your data, by design. Then a breach of the provider is not a breach of your secrets.
Zeromatics Workspace was built for that case: an encrypted vault, document workflow, e-signing and private hosting in one place. It is not the right tool for every team. It is the right tool when you need all four together. You can see the Workspace product page for the detail.