OnionShare is an open-source cross-platform application for sharing files securely and anonymously.
The program uses Tor to temporarily host the files on your computer, and provides you with a cryptic and unguessable URL. Pass this on to the recipient and they can download the file directly from you.
OnionShare requires the Tor browser, but otherwise there’s no special setup or configuration required. Just download and install Tor, run it and you’re ready to go.
Launch OnionShare and you’re able to add as many files or folders as you need to share. Use the “Add” buttons or drag and drop them onto the program.
Click “Start Sharing” when you’re ready, OnionShare creates a Tor service and gives you a URL like “http://nt6ug3sqnkcd3jds.onion/kitten-table”. The .onion part is the Tor URL, and the final two words are effectively a password to your files. An attacker would need both to access the data.
The next step is to get that URL to the recipient, ideally via an encrypted or in-person message. (Send the address in plain text, such as via email, and it’s easily noticed by others).
Once the recipient has the URL, entering it into the Tor browser gives them access to the files, and they can download them locally just like any other. Easy.
OnionShare is an open-source application for Windows and Mac.