Patent ID: 8112632

Claim:
A system for granting a user access to a locked door, the system comprising: a security device including: a knowledge input module obtaining knowledge data; a biometric input module obtaining biometric data; a user data storage module storing user-specific data, the user-specific data includes a seed and an algorithm for pseudo-random code generation; a processor performing a user authorization process in response to the knowledge data, the biometric data and the user-specific data; an emitter in communication with the processor, the emitter emitting a visible, wireless signal indicative of a result of the user authorization process, the wireless signal including the knowledge data as a prefix to the pseudo-random code, the pseudo random code being a common code for multiple users with different knowledge data; a receiving system receiving the signal indicative of the result of the authorization process, the receiving system generating an authorization signal in response to the signal; an access system granting access to the locked door in response to the authorization signal from the receiving system; the processor transmits the pseudo-random code to the emitter in response to the user entering valid knowledge data and valid biometric data; the receiving system verifying the pseudo-random code to generate the authorization signal.