High-security dual-image encryption based on fingerprint key with strong robustness

A high-security dual-image encryption method based on fingerprint key with strong robustness is proposed in this paper by combining a fingerprint higher-order data acquisition technology based on cylinder-code with a security-enhanced optical image encryption method based on chaotic phase Fresnel diffraction. In the proposed method, a large key space is created by employing a portable fingerprint key and a series of easy-stored digital keys, where the fingerprint key exhibits remarkable robustness thanks to the implementation of fingerprint cylinder-code authentication technology during the decryption process, and these digital keys have ultrahigh sensitivities because they are closely mapped with the chaotic initial values in chaotic phase Fresnel diffraction and chaotic phase inverse Fresnel diffraction, which contributes to an extremely high security of dual-image encryption method. Furthermore, the high feasibility, security, and robustness of the proposed dual-image encryption method are demonstrated by performing computational simulations. Most importantly, the strong robustness of fingerprint key, including occlusion robustness, rotation robustness, and blur robustness, is also verified by comparative simulations, demonstrating the high practicability of the proposed dual-image encryption method based on fingerprint key.