The Smell of Data doesn't protect you from hackers. Just like the smell of gas doesn't protect you from inhaling or a spark from igniting it. But both smells serve as alerts that things aren't right, and that you should consider taking action to prevent them from getting worse.
As a physical instrument, the Smell of Data is what happens when you make an aromatherapy diffuser smart. It's an electronic room mister that connects via WiFi to your computer or mobile device, and detects when you've clicked on a link, visited a website, or traveled to a dark corner of the internet that could compromise your device or information.
If you visit an unprotected website on an unsecured WiFi network or hotspot, the scent diffuser's built-in hardware takes note, and sends a signal to the dispenser to unleash the Smell of Data.
I have no idea what data smells like, but the project's designers, Leanne Wijnsma and Froukje Tan, say it's a custom scent users will learn to associate with a potential breach, and respond to accordingly. Their inspiration came from early human hunter / gatherers, who often used their sense of smell to survive. Today, having transitioned to a highly digital word, "our noses can no longer warn us of the lurking dangers in the online wilderness." Unless, they propose, our internet is hooked up and noses keyed in to the Smell of Data.