In a personal identification system 10 for identifying a user on the basis of biometric information, a hologram is formed in a holographic recording portion 13 of an optical information recording medium 12. The hologram is provided by the interference between a reference beam subjected to spatial light modulation by record cryptographic identification information based on the biometric information of the user obtained by a biological information sensor 14 and an object beam. At the time of identification, an information processing device 16 makes validation cryptographic identification information from the biometric information directly obtained from the user, and a spatial light modulator 20 modulates a hologram reproduction reference beam by the validation cryptographic identification information. The right or wrong of a reproduced image is detected, and the leakage of the identification information is prevented.