Multi-image optical hiding system based on visual password

Abstract

The invention discloses a multi-image hiding system based on a visual password. The multi-image hiding system encrypts a plurality of images based on a visual password scheme to obtain a plurality ofshared images, thereafter, a diffractive optical element is designed by using a phase retrieval algorithm, so that after the obtained diffractive optical element is irradiated by laser, different shared images are reproduced at different positions in a rear space, the corresponding shared images are aligned and superposed, and secret information can be decrypted, therefore, the method belongs to non-coherent superposition, is simple and convenient to operate and can effectively suppress noise. According to the multi-image hiding system, the diffractive optical element is used for hiding the plurality of shared images obtained after encryption through adopting the visual password scheme, the controllability of the diffractive optical element on a three-dimensional light field is effectivelyutilized, and the hiding of a plurality of pieces of encrypted information is realized.

Description

technical field [0001] The invention relates to a multi-image hiding system, in particular to a multi-image hiding system which takes a diffractive optical element as a carrier and loads a plurality of secret information images encrypted by a visual cryptography scheme. Background technique [0002] Visual cryptography is an encryption method based on the human visual system's ability to identify correlations and random grids. Visual cryptography is an information encryption technology that uses images as the medium. This technology uses special algorithm rules to encode images carrying information into several shared images with hidden information. As long as a specific number of sub-images are precisely aligned and superposed, no Relying on any cryptography-related knowledge and calculations, the information of the original image can be obtained by deciphering with human eyes. See (Eurocrypt 1994(1):1-12, 1994). [0003] Visual cryptography has better concealment, and se...

AI Technical Summary

Problems solved by technology

Taking a diffractive optical element as an example, a shared image is loaded into a diffractive optical element, and the shared image is reproduced by optical means during decryption, and can be decrypted after superposition. However, the production cost of diffractive optical elements is relatively high, which leads to the same problem in the entire encryption system. higher cost

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