Your computer is leaking information. It's not from the usual suspects: WiFi, Bluetooth or ethernet, but from radio waves originating from your processor. Researchers at Tel Aviv University and Israel's Technion research institute have built a $300 device that captures those electromagnetic waves and uses them to decrypt RSA and ElGamal data from up to 19 inches away. The PITA (Portable Instrument for Trace Acquisition) device is the size of (you guessed it) a pita and was built using off-the-shelf parts and runs on four AA batteries. The stolen data can be saved to the onboard microSD card or sent via WiFi to the attacker's computer. The team demonstrated the hack by extracting the keys from GnuPG. Fortunately, GnuPG was updated when the research paper was published to thwart the delicious-sounding PITA.
While the researchers jokingly placed the device in a pita, the reality is that someone could place one of these devices under the desk of a targeted subject to steal their encryption passkey. Fortunately, the researches alerted GnuPG developers about the attack and worked with them to adjust the software's algorithm. So you're safe for now. But keep a look out for errant pita sandwiches at the local Starbucks.