Secret Data-Driven Carrier-Free Secret Sharing Scheme Based on Error Correction Blocks of QR Codes

In this paper,a novel secret data-driven carrier-free(semi structural formula)visual secret sharing(VSS)scheme with(2,2)threshold based on the error correction blocks of QR codes is investigated.The proposed scheme is to search two QR codes that altered to satisfy the secret sharing modules in the error correction mechanism from the large datasets of QR codes according to the secret image,which is to embed the secret image into QR codes based on carrier-free secret sharing.The size of secret image is the same or closest with the region from the coordinate of(7,7)to the lower right corner of QR codes.In this way,we can find the QR codes combination of embedding secret information maximization with secret data-driven based on Big data search.Each output share is a valid QR code which can be decoded correctly utilizing a QR code reader and it may reduce the likelihood of attracting the attention of potential attackers.The proposed scheme can reveal secret image visually with the abilities of stacking and XOR decryptions.The secret image can be recovered by human visual system(HVS)without any computation based on stacking.On the other hand,if the light-weight computation device is available,the secret image can be lossless revealed based on XOR operation.In addition,QR codes could assist alignment for VSS recovery.The experimental results show the effectiveness of our scheme.

Security Analysis of Secret Image Sharing

Differently from pure data encryption,secret image sharing(SIS)mainly focuses on image protection through generating a secret image into n shadow images(shares)distributed to n associated participants.The secret image can be reconstructed by collecting sufficient shadow images.In recent years,many SIS schemes are proposed,among which Shamir’s polynomial-based SIS scheme and visual secret sharing(VSS)also called visual cryptography scheme(VCS)are the primary branches.However,as the basic research issues,the security analysis and security level classification of SIS are rarely discussed.In this paper,based on the study of image feature and typical SIS schemes,four security levels are classified as well as the security of typical SIS schemes are analyzed.Furthermore,experiments are conducted to evaluate the efficiency of our analysis by employing illustrations and evaluation metrics.

Destructive Method with High Quality and Speed to Counter Information Hiding

Hidden information behavior is becoming more difficult to be detected, causing illegal information spreading. To counter information hiding, more complex and high-dimensional steganalysis methods are applied, and have good detection for some specific information hiding algorithms. However, huge time consumption is needed and only suitable for offline usage with this method. In this paper, a destructive method with high quality and speed is proposed to counter information hiding. The experimental result presents that the extracting error rate of hiding information is around 50%, which means the method can destroy the possible covert communication completely. At the same time, the quality of covers after the destructive operation is good and the average time of operating an image is millisecond.

A Novel Progressive Secret Image Sharing Method with Better Robustness

Secret image sharing (SIS) can be utilized to protect a secret image during transmit in the public channels. However, classic SIS schemes, e.g., visual secret sharing (VSS) and polynomial-based scheme, are not suitable for progressive encryption of greyscale images in noisy environment, since they will result in different problems, such as lossy recovery, pixel expansion, complex computation, "All-or-Nothing"and robustness. In this paper, a novel progressive secret sharing (PSS)method based on the linear congruence equation, namely LCPSS, is proposed to solve these problems. LCPSS is simple designed and easy to realize, but naturally has many great properties, e.g., (k, n) threshold,progressive recovery, lossless recovery, lack of robustness and simple computation.

Clarity Corresponding to Contrast in Visual Cryptography

The visual quality of the recovered secret image is usually evaluated by contrast in visual cryptography (VC). Precisely, the reconstructed secret image can be recognized as the original secret image when contrast is greater than zero. It is important for the user to know the clarity of the revealed secret image corresponding to different contrast values. In this paper, the clarity corresponding to contrast is investigated through conducting subjective evaluation scores and objective evaluation indexes, which can be extended to general applications.