GF (27) finite field and dual authentication-based meaningful (K, N) image sharing and reconstructing method

Abstract

The invention provides a GF (27) finite field and dual authentication-based meaningful (K, N) image sharing and reconstructing method. Ring the sharing period, the sub-band of a secret image LL is scrambled, and the coefficients of bits are backed up by different numbers according to the degrees of importance thereof. Finally, a backup image of the same size with the secret image is formed. After that, secret pixels, backup pixels and the corresponding dual-authentication information are shared in the form of (K, N) in the GF (27) finite field. Based on the optimized LSB method, the shared information and primary authentication bits are embedded into the lower-order bits of a bunker block to maximally ensure the visual quality of distributed bunker images. During the reconstruction process, the shared information for recovery is screened through the primary authentication step. After that, the reliability of recovered secret pixels and the reliability of recovered backup pixels are verified through the secondary authentication step, so that an authentication image, a backup image and a preliminary secret image are formed. In combination with the secret image, a recovered reference image and the authentication image, the non-pass pixels of the secret image during the authentication process are subjected to polynomial fitting repair and alternative repair, so that the repair quality after the attack is better.

Description

technical field [0001] The invention belongs to the cross field of image information security and digital image signal processing, and relates to an image sharing and reconstruction method, in particular to a method based on GF(2 7 ) Meaningful (K,N) Image Sharing and Reconstruction Method for Finite Fields and Dual Authentication. Background technique [0002] Digital image information sharing technology is a research hotspot in image information security. The existing image information sharing technology is mainly derived from secret sharing in cryptography, which was first proposed by Shamir, 1979 (ShamirA. .Safeguardingcryptographickeys[C] / / Proceedingsof1979NationalComputerConference.NewYork,USA:AFIPS,1979,48:313–317.) Combining Lagrange interpolation method and vector space point properties respectively. [0003] Combined with the secret sharing scheme, the image information sharing scheme based on the (K,N) threshold is widely proposed, that is, the secret image is d...

AI Technical Summary

Problems solved by technology

However, Wu,2013 used 2 8-bit secret pixels and 2 4-bit backup image pixels totaling 24 bits as the initial 3-time 8-cell to construct a reversible cellular automaton for sharing, and the sharing information and the corresponding The 8-bit authentication information is embedded into the lower 2 bits of the cover image corresponding to the 2×4 block using the LSB method. The problems caused by this are: ①It is not a real (3,N) threshold scheme, and at least 3 numbers are required The two secret pixels and the backup image of the secret image can be recovered only by continuous sharing units; ②Any pixel in the 2×4 block is attacked, that is, the 24-bit information in the two secret pixels and their backup image is unavailable, Therefore, this method cannot resist any tiny noise attack; ③ It is unreasonable to use the same backup strategy for the low-order bits and high-order bits of each pixel in the LL subband, that is, to back up each pixel bit twice. The accuracy is obviously higher than that of low-order bits, which affects the repair ability of the scheme under large-scale attacks; ④The scheme still uses the traditional LSB method to embed shared storage information and authentication information, resulting in low visual quality of embedded bunker images

[0010] The invention patent applied for: a GF(2 3 ) (K,N) meaningful non-expansion image sharing and reconstruction method, the proposed scheme introduces an authentication strategy for secret pixels, but the proposed strategy does not authenticate the bunker image embedded with shared information, although there are relatively High probability of identifying secret information tampered with, but unable to identify bunkers subject to malicious tampering

Images