Most products encrypt around your files. This one encrypts them where you are, and shares by sealing keys to specific people.
“Sharing is a key operation, not a permission checkbox.”
For anyone comparing encrypted file-sharing tools and trying to work out which claims are architectural.
XChaCha20-Poly1305 with keys derived locally using Argon2id; the server receives ciphertext.
Internal sharing seals the file key to each recipient with X25519, so access is possession of a key.
External recipients get a protected link with passphrase, expiry within 24 hours maximum and revocation.
Blind indexes computed on your device let you find files without the server holding a content index.
File names and folder structure are protected, not only file contents.
Restore earlier versions and deleted items within 30 days.
Ask what the server holds at upload time, whether an administrator can read a shared folder, and what happens cryptographically when you remove someone. Precise answers indicate a real design; phrases such as bank-level encryption or military-grade indicate a brochure.
These are different problems. Internally, you want continuous access managed by membership and revoked by rotation. Externally, you want a short-lived, revocable, passphrase-gated link for someone who will never create an account. Using the wrong mechanism for either is how permanent public links end up in the world.
No provider-side previews of everything, no integrations that read your data, and no administrator password reset — recovery depends on an offline kit. These follow directly from the guarantee.
Yes, through a protected link that works in any browser with no account.
Yes. Names and structure are encrypted alongside contents, because a folder tree can disclose as much as a document.
No. Files are encrypted on your device with XChaCha20-Poly1305 before the upload starts, using keys derived locally with Argon2id. Our servers hold ciphertext only, so there is no preview, no scanning and no staff view of your transfer.
No. They open the link in any browser, type the passphrase you shared separately, and the file is decrypted locally on their machine. Nothing to install, nothing to sign up for.
Public share links always expire within 24 hours at most, and you can make them shorter, limit the number of views, or revoke them instantly. Expiry is enforced by the system, not by a reminder.
Uploads are chunked, resumable and verified after upload, so multi-gigabyte transfers survive a dropped connection, a closed laptop or a hotel network. You resume instead of starting again.
Yes. The free plan includes 1 GB with exactly the same zero-knowledge architecture as paid plans, so you can test a real client hand-off before paying anything.
Because we cannot read your data, we cannot reset it for you. Each account creates a Recovery Kit — a printable PDF with a QR code — to store offline. That is the same property that keeps anyone else, including us, out of your account.
Start free with 1 GB. Zero-knowledge encryption from the first upload — no admin override, no AI scanning, no plaintext on the server.
