Services that store your files online. For each of the 5 we reviewed, we look at who holds the encryption keys, what is encrypted besides the files themselves, what happens if you lose your password, whether an independent audit exists, and what it costs.
Proton Foundation · Switzerland
Proton Foundation · Switzerland
Filen Cloud Dienste UG (haftungsbeschränkt) · Germany
Filen Cloud Dienste UG (haftungsbeschränkt) · Germany
Swiss Post · Switzerland
Swiss Post · Switzerland
Independent company · Hungary
Independent company · Hungary
Sync.com Inc. · Canada
Sync.com Inc. · Canada
Every storage service is scored out of 10 against five weighted categories. Who holds the encryption keys carries the most weight, and what a provider says about its encryption is kept apart from what an independent audit has confirmed.
Who holds the keys, whether file names and metadata are encrypted as well, whether shared files stay encrypted, and what happens if you lose your password. A service that holds the keys itself cannot score high here.
Whether the client and server code are open, whether the builds can be reproduced, whether an independent audit exists and who paid for it, plus jurisdiction, owner and breach history.
Desktop sync, file versions, collaborative editing and file size limits. Private services often lose search, previews and shared editing as the price of encryption, and that loss is scored here rather than hidden.
Quality of the apps and web interface, platform coverage, and how simple sharing and recovery are for someone who is not technical.
Judged on the renewal price for a named amount of storage, not the first-year rate, together with the free allowance and any lifetime plan.
"Encrypted" is the claim every storage service makes, and it says little until you know who holds the keys. The rubric therefore starts there. Encryption & Key Custody asks whether the provider can read your files, whether file names and metadata are covered too, whether sharing a file keeps it encrypted, and what happens if you lose your password. Trust & Transparency asks whether the code is open, whether an audit exists and who paid for it.
It means the provider says it cannot read your files. We show it as the provider's own statement until an independent audit confirms it, and we name who paid for any audit. Even then the provider still sees file sizes, when you connect, your IP address and your payment details.
A server that cannot read your files cannot search inside them, preview them or edit a document with other people. Features & Sync scores that loss separately from ease of use, so it shows up in the rating instead of hiding behind a friendly app.
Some services have none. A missing audit is not scored anywhere else: it only limits how much Trust & Transparency can earn, and the review says plainly that none exists.