KOSTET SECURE DOCUMENT TRANSFER
Send confidential files securely.
Choose your documents, add an optional message and press send. The secure service encrypts the complete submission in your browser before it leaves your device.
No account · No software installation · No shared password
Drag in one or several files. There are no accounts, keys or encryption settings to manage.
Documents, filenames, message and sender details are protected together inside the encrypted submission.
After a successful upload, you receive a reference number that can be quoted by telephone or email.
HOW IT WORKS
As easy as attaching a file.
The normal workflow is designed for customers and partners who simply need to send material securely. The cryptography is automatic and remains out of the way.
Choose documents
Select or drag in PDFs, Office documents, drawings, ZIP files, photographs or other project material. Multiple files can be sent together.
Send securely
Add optional contact details, a reference and a message. Press one button; the browser prepares, encrypts and uploads the submission.
Keep the reference
The confirmation page provides a submission reference. Keep it if you want to confirm receipt with Kostet through another channel.
SECURITY MODEL
The server stores ciphertext, not your documents.
The secure-transfer service is separated from the main Kostet website. It is deliberately small and purpose-built so that confidential file handling is not mixed with ordinary website functions.
Protected in the browser
- Encryption takes place on your device before transmission.
- Original filenames, optional message and sender details are encrypted with the files.
- The upload is additionally protected by HTTPS while in transit.
- The private decryption key is held separately from the web server.
HIGHER ASSURANCE
Encrypt before visiting the website
For especially sensitive material, Kostet can provide a public encryption key and offline instructions. You encrypt the files locally first, then upload only the already-encrypted package. In that workflow, the browser never handles the plaintext document.
Contact Kostet for offline encryption details →READY TO SEND?
Open the secure upload service.
Choose your files and send them securely to Kostet. No registration or software installation is required.
Send documents securely ↗