A device for detecting a timeout event during a transaction between a user and a host includes a memory storing a set of predetermined threshold values in association with corresponding operations. A timing control unit that is operative to provide timing information. A controller is operative to detect a timeout event based on the timing information provided thereto and on the predetermined threshold vale of a corresponding operation. Activation of the device is conditional upon a signal received from a host. In another example embodiment, a device for detecting a timeout event during a transaction between a user and a host based on timing information and the predetermined threshold values includes means to access external power from the host.