Building PlainTray: Zero-Knowledge File Sharing That Just Works

February 14, 2026

Sharing a file securely in 2026 is still surprisingly annoying. Email attachments have size limits and sit unencrypted on some server. WeTransfer is convenient but they can read everything you upload. Dropbox and Google Drive require accounts on both ends. And self-hosted solutions are great until you realize you’re now responsible for keeping a server patched and running. I first tried to solve this back in 2014 with a Java web app I built at university.