Abstract: A logic circuit is described. The logic circuit generates a first signal state in response to a first set of input signals, generates a second signal state in response to a second set of input signals, activates a bypass switch in response to the first signal state, and bypasses a domino logic unit in response to the first signal state.

Abstract: An intelligent security device (10) is disclosed for protecting computer software from unauthorized use. The security device (10) is a hardware device having within a microprocessor (36) for interacting with a host computer (32) such that protected software may not be operated unless the security device (10) is in place. Physical duplication of the security device (10) will not result in a workable copy, due to the nature of the microprocessor (36), which is such that information is encoded therein and further such that encryption codes are also stored therein and cannot be discovered after the microprocessor (36) is locked by any known means. A system clock (21) within the microprocessor (36) is adaptable to the purpose of permitting use of the protected software only within limited time parameters.