High secure authentication by optical multifactor ID tags

摘要

Multifactor encryption-authentication technique reinforces optical security by allowing the simultaneous AND-verification of more than one primary image. The method involves double random-phase encoding, fully phase-based encryption and a combined nonlinear JTC and a classical 4f-correlator for simultaneous recognition and authentication of multiple images. The encoded signal fulfils the general requirements of invisible content, extreme difficulty in counterfeiting and real-time automatic verification. Four reference images, double-phase encoded and encrypted in an ID tag are compared with the input images obtained in situ from the person or the vehicle whose authentication is wanted and from a database. Optical ID tags are satisfactory items to achieve remote and real-time optical authentication. On the one hand, effort has been focused on the tag design to provide a positive identification even though the receiver captured the ID tag under some distortion. On the other hand, demands on increasing security require ciphering the information prior to include it in the ID tag. A recognition step based on the correlation between the retrieved signature and a stored reference determines the authentication or rejection of the object under surveillance. In this work, we combine optical ID tags with the multifactor authentication procedure. Instead of basing the identification on a unique signature or piece of information, our goal is to authenticate a given person, object, or vehicle, by the simultaneous recognition of several factors. Some of them are intrinsic to the person and vehicle under control. Other factors, act as keys of the authentication step. The information of the whole set of factors is included in the ID tag. Remote identification of all factors is achieved. Such a system is proposed to control the access of people and vehicles in restricted areas, where the demand of security is high.