Abstract:In conventional meaningful image sharing schemes, there exist some shortages such as low authentication ability, weak to no repair or recovery ability after being attacked, and low visual quality in embedded carriers. To address these problems, this paper proposes a Gloise field self-recovery image sharing scheme with non-equivalent backup and double authentication. The proposed scheme includes both distributing and recovery stages. The distributing stage include three steps. First, the LL subband of the secret image is obtained by one layer DWT and then the LL subband coefficients is scrambled by a secret key to generate the non-equivalent backup image according to different bit important degree groups where both the backup image and the secret image are in same size. Second, each pixel in both the secret image and the backup image are shared with their 7K-13 authentication bits into 7 bits distributed information on GF(27), and then the distributed 7 bits information with its 1 bit authentication generated by the secret key is embedded into 2×2 blocks of N distributed carriers by the optimized LSB embedding method. Finally, the secret key used to scramble LL subband and generate 1 bit authentication is also shared into N sub-keys by(K,N)-threshold scheme, and then the sub-keys' MD5 values are published into the third reliable party and theNsub-keys and embedded carriers are distributed toNparticipants. The recovery stage has four steps. First, the facticity of participants' sub-keys is verified, and then the sub-keys are used to recovery the secret key. Second, the embedded distributed information with its 1 bit authentication is checked by the first authentication, the checked distributed information is used to reconstruct GF(27) interpolation polynomial, and then the pixels in the secret image and the backup image with their 7K-13 authentication bits are recovered to construct the preliminary secret image, backup image and authentication image. Third, the backup image and authentication image are used to reconstruct the LL subband of the secret image and then to build the repair reference image by the descramble method and inverse DWT. Finally, the unpassed secret image pixels in the authentication image are self-recovered by the polynomial interpolation fitting and pixel replacement in repair reference image. The theory and experiment show the proposed method has a superb authentication ability and can make full use of double authentication ability and the adjoin pixels to improve its self-recovery ability, and the embedded carriers have better visual qualities.