Biblio

An efficient and reversible meaningful image encryption scheme is proposed in this paper. The plain image is first compressed and encrypted simultaneously by Adaptive Block Compressive Sensing (ABCS) framework to create a noise-like secret image. Next, Least Significant Bit (LSB) embedding is employed to embed the secret image into a carrier image to generate the final meaningful cipher image. In this scheme, ABCS improves the compression and efficiency performance, and the embedding and extraction operations are absolutely reversible. The simulation results and security analyses are presented to demonstrate the effectiveness, compression, secrecy of the proposed scheme.

Remote authentication via biometric features has received much attention recently, hence the security of biometric data is of great importance. Here a crypto-steganography method applied for the protection of biometric data is implemented. It include semantic segmentation, chaotic encryption, data hiding and fingerprint recognition to avoid the risk of spoofing attacks. Semantically segmented image of the person to be authenticated is used as the cover image and chaotic encrypted fingerprint image is used as secret image here. Chaotic encrypted fingerprint image is embedded into the cover image using Integer Wavelet Transform (IWT). Extracted fingerprint image is then compared with the fingerprints in database to authenticate the person. Qualified Significant Wavelet Trees (QSWT`s) of the cover image act as the target coefficients to insert the secret image. IWT provide both invisibility and resistance against the lossy transmissions. Experimental result shows that the semantic segmentation reduces the bandwidth efficiently. In addition, chaotic encryption and IWT based data hiding increases the security of the transmitted biometric data.

Chang-Chen-Wang's (3,n) Secret grayscale image Sharing between n grayscale cover images method with participant Authentication and damaged pixels Repairing (SSAR) properties is analyzed; it restores the secret image from any three of the cover images used. We show that SSAR may fail, is not able fake participant recognizing, and has limited by 62.5% repairing ability. We propose SSAR (4,n) enhancement, SSAR-E, allowing 100% exact restoration of a corrupted pixel using any four of n covers, and recognizing a fake participant with the help of cryptographic hash functions with 5-bit values that allows better (vs. 4 bits) error detection. Using a special permutation with only one loop including all the secret image pixels, SSAR-E is able restoring all the secret image damaged pixels having just one correct pixel left. SSAR-E allows restoring the secret image to authorized parties only contrary to SSAR. The performance and size of cover images for SSAR-E are the same as for SSAR.

Chang-Chen-Wang's (3,n) Secret grayscale image Sharing between n grayscale cover images method with participant Authentication and damaged pixels Repairing (SSAR) properties is analyzed; it restores the secret image from any three of the cover images used. We show that SSAR may fail, is not able fake participant recognizing, and has limited by 62.5% repairing ability. We propose SSAR (4,n) enhancement, SSAR-E, allowing 100% exact restoration of a corrupted pixel using any four of n covers, and recognizing a fake participant with the help of cryptographic hash functions with 5-bit values that allows better (vs. 4 bits) error detection. Using a special permutation with only one loop including all the secret image pixels, SSAR-E is able restoring all the secret image damaged pixels having just one correct pixel left. SSAR-E allows restoring the secret image to authorized parties only contrary to SSAR. The performance and size of cover images for SSAR-E are the same as for SSAR.

Visual cryptography is a way to encrypt the secret image into several meaningless share images. Noted that no information can be obtained if not all of the shares are collected. Stacking the share images, the secret image can be retrieved. The share images are meaningless to owner which results in difficult to manage. Tagged visual cryptography is a skill to print a pattern onto meaningless share images. After that, users can easily manage their own share images according to the printed pattern. Besides, access control is another popular topic to allow a user or a group to see the own authorizations. In this paper, a self-authentication mechanism with lossless construction ability for image secret sharing scheme is proposed. The experiments provide the positive data to show the feasibility of the proposed scheme.