Buy a camera that uses dual SD cards, like a Nikon D7000, and keep the card in the camera when moving through security. Store your computer data on one of the SD cards in an encrypted hidden file. Make sure you take lots of pictures and have the camera set to use the cards in mirror mode. No security people will image a camera card. At best they look at all the pictures using the camera. If they do image the card, highly unlikely, all they can find is a hidden encrypted file that you just deny any knowledge of.