WASHINGTON — The latest form of cellphone messaging goes back to one of the earliest forms of communication – and it’s free, totally secure and doesn’t depend on finding reception: smoke signals.

Inventor Dennis Be Bel‘s iPhone case vaporizes lamp oil and sends out a puff of smoke. You can manipulate the puffs to send different messages – the meanings of which only you and the person you’re signaling will know.

WTOP’s David Burd contributed to this report. Follow @WTOP on Twitter and on the WTOP Facebook page.