A computer or other electronic device requiring physical integrity of its components, for example, a pay-per-use computer may use a master security device in communication with a plurality of slave security devices, known as security beans. Each security bean may be given a cryptographic key or keys for use in authenticating communication with the master security device. Each security bean may be coupled to an associated component and may have the ability to disable that associated component. In one embodiment, security bean has an analog switch that may be configured to block or attenuate a critical signal used by the associated component. The security bean may start up in the disable mode and respond to a verified signal from the master security device to enable its corresponding component.