A Multi-Threshold Progressive Secret Image Sharing and Reconstruction Method in Prime Field

Abstract

The invention provides a prime-domain multi-threshold progressive secret image sharing and reconstruction method. The method comprises the steps that a random participation value is combined to share a secret key, and the shared secret key and an MD5 value corresponding to the participation value are announced to prevent cheating; a secret image is subjected to 8*8 frequency domain transform; random quantization and binary representation with a specified code length allocation table are carried out on a block frequency domain coefficient; a number of divided bands are formed according to a zigzag scanning order and band recombination, and band backup is formed through scrambling; multi-threshold sharing is carried out on the bands, the band backup and authentication information in prime-domain; and a distribution shadow image is reconstructed with additional 1-bit authentication information. When recovery is carried out, the MD5 value is detected, and multiple thresholds are combined to determine a reconstructable band; double authentication are used to reconstruct first and secondary band backup tables and the corresponding band; and the reconstructed band is used to reconstruct the secret image. Compared with the existing methods, the provided method can make full use of the distribution shadow image to carry out progressive sharing on the secret image to enhance the quality of visual reconstruction.

Description

technical field [0001] The invention belongs to the cross field of image information security and digital image signal processing, relates to an information sharing method, in particular to a prime number domain multi-threshold progressive secret image sharing and reconstruction method. Background technique [0002] The existing image information sharing technology is mainly derived from the secret sharing in cryptography. Combined with the secret sharing scheme, the image information sharing scheme based on (K, N) threshold has been widely proposed. The early image information sharing scheme based on (K, N) threshold There is no authentication measure in the information sharing scheme, so the authenticity of the final reconstructed secret image cannot be verified. Aiming at the potential safety hazards in the use of image sharing schemes without authentication measures, some literatures also discuss image sharing with authentication. For example, Lin C C, 2004 (Lin C C, Ts...

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Problems solved by technology

But the proposed method is to use 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. The problem caused by this is: it is not The real (3,N) threshold scheme requires at least 3 shared storage units with consecutive numbers to recover 2 secret pixels of the secret image and 2 backup pixels of the backup image; any pixel in the 2×4 block Attacked, that is, the 24-bit information of the 2 secret pixels and the 2 pixels of the backup image is unavailable, so the method cannot resist any small noise attack

[0007] Kong J,2007(Kong J,Zhang Y,Meng X,et al.A Scalable Secret ImageSharing Method Based on Discrete Wavelet Transform[C] / / Bio-Inspired Computational Intelligence and Applications,International Conference on LifeSystem Modeling and Simulation,LSMS 2007, Shanghai, China, September 14-17, 2007, Proceedings.2007:736-745.) Combined with the work of Chen S K, 2005, perform block DWT transformation on the image to be shared, and perform integer quantization and bit-plane reorganization on the transformed coefficients , according to the importance of the bit plane where the recombined DWT coefficients are located, different thresholds are assigned to achieve progressive sharing. However, compared with spatial domain pixels, the importance of frequency domain coefficients is usually closely related to the coefficient frequency, that is, the position, and it simply depends on the frequency domain. The degree of importance of the bit planes divided by the coefficients still has a very limited effect on the visual control of the image

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