| 摘要 |
In an authentication system for badges carried by persons, a base station, in response to an infra-red call-up signal from a badge, challenges the carrier with an infra-red PPM signal in the form of a random number and the badge (Fig. 1) generates an encrypted infra-red PPM response signal obtained by combining the random number with a unique password to be verified at the base station before a signal signifying authentication is produced. e.g. to unlock an access door. <IMAGE> |
