Leaving your hotel room for a while? Don’t leave your laptop on. Shut it down lest it becomes subject to a cold boot attack. This is a type of a side channel attack in which an attacker with physical access to the computer can retrieve encryption keys from a running operating system after using a cold reboot to restart the machine. The attack allows a hacker to steal information stored in RAM in only a few minutes. Keep in mind that for a cold boot attack the hacker must have physical control of the device. The simplest way to stop this from happening is to fully shut down your computer – leaving it in sleep mode will not protect it.