A gf (2 6 ) Finite Field Multi-Threshold Progressive Secret Image Sharing and Reconstruction Method

Abstract

The present invention provides a GF (2 6 ) Finite field multi-threshold progressive secret image sharing and reconstruction method. This method first shares the key with random participation values, and publishes the MD5 values ​​corresponding to the shared keys and participation values ​​to prevent cheating; then the secret image is 8×8 frequency domain transformation, randomly quantizing the block frequency domain coefficients and specifying the binary representation of the code length allocation table, forming multiple divided frequency bands according to the zigzag scanning sequence and frequency band reorganization, and forming frequency band backup through scrambling; secondly Band, band backup and authentication information are provided in GF(2 6 ) finite domain performs multi-threshold sharing, and appends 2-bit authentication information to reconstruct and distribute the shadow image. During recovery, the MD5 value is first detected and combined with multiple thresholds to determine the reconstructable frequency band, and then double authentication is used to reconstruct the primary and secondary frequency band backup tables and the corresponding frequency bands, and the reconstructed frequency band is used to reconstruct the secret image. Compared with existing methods, the proposed method can make full use of distributed shadow images to progressively store secret images and improve the quality of visual reconstruction.

Description

technical field [0001] The invention belongs to the intersecting field of image information security and digital image signal processing, relates to an information sharing method, in particular to a GF(2 6 ) Finite-field 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 (L...

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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

[0006] 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 sharing thresholds are allocated to realize progressive sharing. However, compared with spatial domain pixels, the importance of frequency domain coefficients is usually closely related to the frequency of the coefficients, that is, the position. 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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