High speed wide bandwidth optical encryption and decryption system using spatial codes

For security systems that use optical technology, users are issued 2-D spatially coded ID cards. This paper introduces optical encryption and decryption systems that use several features of optical technology to provide highly secure ID verification. In particular, these systems use high speed electronically controlled optical scanning of ID cards. The optical transmitter is a coherent interferometric system that includes the scanning system and the transmit/receive fiber-optics with only one fiber input/output port. In short, these systems are very sensitive to unwanted external tampering