Abstract: An integrated circuit has a keypress entry interface and a pass-through data path. In a pass-through mode, the keypress entry interface is disabled and the pass-through data path is enabled such that untrusted information (for example, video) from an external untrusted source can be driven into the integrated circuit, through the pass-through data path, and out of the secure integrated circuit and to a display. In a trusted mode, the keypress entry interface is enabled and is usable to receive keypress information in a financial transaction. The pass-through data path is, however, disabled so that unauthorized information cannot be driven through the integrated circuit to the display. Signed images previously stored on the integrated circuit can be verified and driven to the display in a secure fashion. The architecture is flexible and allows an external general purpose video decoder to be used to drive the display in the pass-through mode.

Abstract: An integrated circuit has a keypress entry interface and a pass-through data path. In a pass-through mode, the keypress entry interface is disabled and the pass-through data path is enabled such that untrusted information (for example, video) from an external untrusted source can be driven into the integrated circuit, through the pass-through data path, and out of the secure integrated circuit and to a display. In a trusted mode, the keypress entry interface is enabled and is usable to receive keypress information in a financial transaction. The pass-through data path is, however, disabled so that unauthorized information cannot be driven through the integrated circuit to the display. Signed images previously stored on the integrated circuit can be verified and driven to the display in a secure fashion. The architecture is flexible and allows an external general purpose video decoder to be used to drive the display in the pass-through mode.