Prime-domain multi-threshold progressive secret image preservation and reconstruction method

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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