Methods and systems for protecting data that is intended for use and processed on video or graphics cards are described. In various embodiments, data that is intended for use by a video card can be encrypted such that any time the data is provided onto a bus (e.g. a PCI or AGP bus) between the video card and the computer system, the data is encrypted. For example, when data is moved from memory on the video card to the system's memory (e.g. when it is mapped to the system's physical memory) and vice versa, the data is in encrypted form and thus protected.