Abstract: A pay-per-use computer, or other electronic device that uses local security, may use a security module or other circuit for monitoring and enforcement of a usage policy. To help prevent physical attacks on the security module, or the circuit board near the security module, a second circuit may be mounted over the security module to help prevent access to the security module. Both circuits may be mounted on a interposer and the interposer mounted to the circuit board, creating a stack including the first circuit, the interposer, the security module, and a main PC board. When the PC board includes dense signal traces under the security module a three dimensional envelope is created around the security module. When the first circuit is a high value circuit, such as a Northbridge, the risk/reward of attacking the security module is increased substantially and may deter all but the most determined hackers.

Abstract: A pay-per-use computer, or other electronic device that uses local security, may use a security module or other circuit for monitoring and enforcement of a usage policy. To help prevent physical attacks on the security module, or the circuit board near the security module, a second circuit may be mounted over the security module to help prevent access to the security module. Both circuits may be mounted on a interposer and the interposer mounted to the circuit board, creating a stack including the first circuit, the interposer, the security module, and a main PC board. When the PC board includes dense signal traces under the security module a three dimensional envelope is created around the security module. When the first circuit is a high value circuit, such as a Northbridge, the risk/reward of attacking the security module is increased substantially and may deter all but the most determined hackers.

Abstract: In response to a user instruction to initiate media playback, which instruction may come from a dedicated media playback hardware button or from a user interface on a display screen, a computer operating system activates a predesignated media playback user account. The account may be limited to access of media playback applications and files located within shared directories. The operating system also launches a media playback application in response to the user instruction to initiate media playback. Instead of activating an account in response to a media playback instruction, the operating system can execute a media player application within a login screen.

Abstract: An SPI switch allows selection of a BIOS memory transparent to a Southbridge chipset component. The SPI switch provides address translation to a selected BIOS memory area under the control of a security module processor. The SPI switch also provides command filtering to prevent commands that represent a security risk such as bulk erase commands. Because the SPI switch allows transparent redirection between BIOS programs, booting in different operating modes may be supported without any changes to the basic computer architecture or major chipset components.