Visual Cryptography Scheme Research Articles

EVCS-DAS: Evolving Visual Cryptography Schemes for Dynamic Access Structures

A systematic investigation of evolving visual cryptography scheme (EVCS) is carried out in this paper. The evolving scheme, denoted as \((k,\infty)\) , differs from the \((k,n)\) threshold in that it permits an arbitrary and perhaps unlimited number of participants. More importantly, the access structure can be updated dynamically by adding new users. First of all, a preliminary implementation strategy for the \((2,\infty)\) EVCS is introduced. Then, by employing the \((2,2)\) VCS recursively with the \((2,\infty)\) EVCS, a \((k,\infty)\) EVCS is created. In order to enhance the performance, an improved scheme is constructed based on the multi-secret VCS (MVCS) and a series of EVCS schemes with thresholds of \((1,\infty)\) , \(\cdots\) , \((k-1,\infty)\) . Moreover, Boolean XOR operation is adopted for secret recovery to further improve the visual quality. To facilitate the XOR decryption, a novel access structure partition algorithm is presented. Additionally, the proposed partition method can successfully solve the security issue in existing multi-secret XOR-based VCS (MXVCS). By integrating the more secure MXVCS into the improved scheme, XOR decryption is provided. The two proposed methods are shown to be effective and advantageous through extensive experiments and comparisons.

Maximizing Contrast in XOR-Based Visual Cryptography Schemes

Maximizing Contrast in XOR-Based Visual Cryptography Schemes

VISUAL CRYPTOGRAPHY WITH COLOR IMAGE ENCRYPTION VIA IMPROVED ELLIPTIC CURVE CRYPTOGRAPHY (ECC) AND OTP GENERATION: SELF-IMPROVED GOLD RUSH OPTIMIZATION ALGORITHM FOR OPTIMAL KEY GENERATION

Visual Cryptography is a cryptographic technique that involves encrypting images in such a way that decryption can be performed visually without the need for complex computations. This technique holds significant importance in secure image sharing, as it ensures that sensitive visual information remains confidential during transmission. Recognizing this significance, a novel approach named Self-Improved Gold Rush Optimization (SIGRO)-based Visual Cryptography has been proposed in this research. This approach encompasses two main phases: Embedding and Extraction. It involves encrypting three original images and two secret images using various encryption techniques such as Random grid-based secret image sharing, Extended Visual Cryptography Scheme (EVCS), and Kronecker product-based encryption, along with the integration of security measures like Modified HMAC-based One-Time Password generation technique (MHOTP) for Improved Elliptic Curve Cryptography (IECC)-based encryption and Baker's map-based encryption. In Kronecker product-based encryption stage, the SIGRO algorithm is utilized to generate optimal keys for encryption purposes. The SIGRO algorithm is proposed as a well-versed approach than the conventional Gold Rush Optimization (GRO) algorithm, incorporating three key enhancements. These enhancements significantly contribute to the efficacy and reliability of the SIGRO algorithm in generating optimal keys for Kronecker product-based encryption. Furthermore, the IECC-based encryption utilizes the MHOTP generation technique, where the OTPs generated by this technique serve as the keys for this encryption stage, enhancing the ECC algorithm into an IECC algorithm. The decryption process involves reversing the steps applied during various encryption stages. This proposed approach's significance lies in its ability to enhance security through a combination of encryption methods and security measures.

Improving Multi-pixel Visual Quality of Invariant Visual Cryptography Scheme

A visual cryptography scheme (VCS) splits the secret image into several shares. Stacking a certain number of shares will reveal the secret image. The principle algorithm (deterministic algorithm) retains the size of shares, and the revealed image is at least double the size of the secret image with good visual quality. In contrast, the probabilistic algorithm has the size of the revealed image equal to that of the secret image with the noisily revealed image. Multi-pixel algorithm cast solutions for the trade off problems between the good visual quality and the non-expansion size of the revealed image. In this paper, we introduce new algorithms for multi-pixel to improve the quality of preceding algorithms, generalize the multi-pixel algorithm, provide evidence of the best form of multi-pixel, and contribute to the thin line problem.

A novel approach for long-term secure storage of domain independent videos

Long-term protection of multimedia contents is a complex task, especially when the video has critical elements. It demands sophisticated technology to ensure confidentiality. In this paper, we propose a blended approach which uses proactive visual cryptography scheme along with video summarization techniques to circumvent the aforementioned issues. Proactive visual cryptography is used to protect digital data by updating periodically or renewing the shares, which are stored in different servers. And, video summarization schemes are useful in various scenarios where memory is a major concern. We use a domain independent scheme for summarizing videos and is applicable to both edited and unedited videos. In our scheme, the visual continuity of the raw video is preserved even after summarization. The original video can be reconstructed through the shares using auxiliary data, which was generated during video summarization phase. The mathematical studies and experimental results demonstrate the applicability of our proposed method.

Visual Cryptography for Color Images using Digital-Watermarking

Visual cryptography is a cryptographic technique which allows visual information (e.g. picture, texts) to be encrypted in such a way that the decryption can be performed by the human visual system, without the aid of computers. There are various measures on which performance of visual cryptography scheme depends, such as pixel expansion, contrast, security, accuracy, share generated is meaningful or meaningless, type of secret images( either binary or color) and number of secret images(either single or multiple) encrypted by the scheme. In visual cryptography encryption of image is done by dividing the image into n number of shares and decryption process is done by combining a certain number of shares or more. simple visual cryptography is not secure because of the decryption process done by visual system. The information or the image can be retrieved by anyone if the person gets at least some number of shares. Secret image can be reconstructed without any complex computation. In this project we use digital watermarking. Digital watermarking is a technique for inserting secret information into an image, which enables us to know the source or owner of the copyright

ADVANCED SECURITY IN CLOUD COMPUTING OF MILITARY WEAPONS

Cloud storage systems are widely deployed in the world, and many people use them to download and upload their personal stuff like videos, text document, images, etc. Now a day many private firms, company’s, governments, military move their database on cloud storage. However, a significant question is, can users trust the media services provided by the media cloud service providers? Many traditional security approaches are proposed to secure the data exchange between users and the media cloud. However, the problem comes to military users if scientist develop a new weapon for military and he want to send a launching code to military admirals /chiefs through cloud, how he can trust cloud that he’s codes will be safely delivered to admirals. Now a day’s cloud storage can easily have cracked by hacker and gain information of military weapons and confidential secrets. It could be dangerous if they sold this information to terrorists or rival country, in this article, we propose to use steganography, watermarking, image encryption and visual cryptography schemes to protect military weapons data in clouds. steganography allows users to hide the weapons launch code in image captcha. Visual cryptography shares the image captcha in shares which is depend on number peoples in group in military. image encryption will apply on each share of captcha. After this watermarking is apply on each share for authentications between users and cloud. For receiving the launch code receivers have to from de-watermarking, image decryption then visual cryptography to get captcha and launch code. Our studies show that the proposed approach achieves good security performance and securing the future of country.

Contrast Enhancement in Probabilistic Visual Cryptography Schemes: A Pixel-Count based Approach

Contrast Enhancement in Probabilistic Visual Cryptography Schemes: A Pixel-Count based Approach

Contrast enhancement in probabilistic visual cryptography schemes: a pixel count based approach

Contrast enhancement in probabilistic visual cryptography schemes: a pixel count based approach

Security enhanced random grid visual cryptography scheme using master share and embedding method

Security enhanced random grid visual cryptography scheme using master share and embedding method

Enhancement of Information Carrying and Decoding for Visual Cryptography with Error Correction

Recently, three visual cryptography schemes with t -error-correcting capability (VCSs- t EC) were introduced for preventing the shadows carrying additional information from being corrupted by noise interference. However, the concerns on VCS- t EC, such as the average amount of carrying information, decoding of information from shadows, and the demonstration way of a secret, should be considered and improved. In this paper, two schemes, namely the ( k , n ) probabilistic VCS- t EC (PVCS- t EC) and the (2, n ) deterministic VCS- t EC (DVCS- t EC), are proposed. The concept of probabilistic VCS is combined with the Bose-Chaudhuri-Hocquenghem code (BCH code) for designing the ( k , n ) PVCS- t EC. Further, some constant-weight BCH codewords are adopted to build the (2, n )-DVCS- t EC. Comprehensive results and experiments are demonstrated to clarify the enhancement of information-carrying and decoding by the two proposed methods.

Optimal Multisecret Image Sharing Using Lightweight Visual Sign-Cryptography Scheme With Optimal Key Generation for Gray/Color Images

Problem: Digital devices are becoming increasingly powerful and smart, which is improving quality of life, but presents new challenges to privacy protection. Visual cryptographic schemes provide data sharing privacy, but have drawbacks such as extra storage space, lossy secret images, and the need to store permutation keys. Aim: This paper proposes a light-weight visual sign-cryptography scheme based on optimal key generation to address the disadvantages of existing visual cryptographic schemes and improve the security, sharing quality, and time consumption of multisecret images. Methods: The proposed light-weight visual sign-cryptography (LW-VSC) scheme consists of three processes: band separation, shares generation, and signcryption/un-signcryption. The process of separation and shares generation is done by an existing method. The multiple shares of the secret images are then encrypted/decrypted using light-weight sign-cryptography. The proposed scheme uses a novel harpy eagle search optimization (HESO) algorithm to generate optimal keys for both the encrypt/decrypt processes. Results: Simulation results and comparative analysis showed the proposed scheme is more secure and requires less storage space, with faster encryption/decryption and improved key generation quality. Conclusion: The proposed light-weight visual sign-cryptography scheme based on optimal key generation is a promising approach to enhance security and improve data sharing quality. The HESO algorithm shows promise in improving the quality of key generation, providing better privacy protection in the face of increasingly powerful digital devices.

Sharing Secret Colour Images with Embedded Visual Cryptography Using the Stamping Algorithm and OTP Procedure

Finding a way to ensure the safety of media is becoming increasingly common in the modern world as digital media usage increases. Visual cryptography (VC) offers an efficient method for sending images securely. Images that have been protected using visual encryption can be decoded using features of human vision. Emails are not a highly safe method of exchanging private data because someone else can quickly weaken the content. In the visual cryptography technique, we presented for colour pictures, the divided shares are enclosed in additional pictures using stamping. Using a random number generator, the shares are created. Visual cryptography schemes (VCS) are a method of encoding pictures that conceals the secret information which is present in images. A secret image is encrypted using a straightforward visual cryptography technique by splitting it into n shares, and the stamping operation is carried out by overlapping k shares. It can be beneficial for hiding a secret image. There is a chance that employing cryptography for information exchange could cause security problems because the process of decryption of simple visual cryptographic algorithms can be completed by the human eye. To address this issue, we are using the OTP procedure. In the past, static ID and passwords were employed, making them susceptible to replay and eavesdropping attacks. One Time Password technology, which generates a unique password each time, is utilized to solve this issue. The suggested approach strengthens the security of the created transparencies by applying an envelope to each share and employing a stamping technique to address security vulnerabilities that the previous methods had, such as pixel expansion and noise.

A hybrid approach combining data hiding with visual cryptography for secure extraction of data hiding

Visual cryptography scheme (VCS) naturally provides a solution for protecting a secret image in a group environment. However, most of the existing VCSs proposed so far only protect one secret image. In this work, we design a hybrid scheme combining VCS and data hiding to simultaneously safeguard the secret image and some related information (e.g., the description of the secret image). First of all, a framework for the hybrid scheme is introduced. Algorithms for building the proposed framework are given. Generally, a secret image is partitioned into k shadows in which the additional messages are embedded. By stacking k shadows, the secret image is visually revealed, and meanwhile, the embedded messages can be securely extracted from the stacked result. Moreover, the performance of the proposed technique would suffer as a result when the threshold k becomes larger. At this time, we have larger pixel expansion, smaller contrast, and reduced data hiding efficiency. To make the scheme more practical, an improved approach is presented for reducing the pixel expansion, increasing the visual quality of recovered image, and enhancing the data hiding efficiency. Comprehensive theoretical analysis and experiments are demonstrated to clarify the effectiveness and advantages of the proposed methods.

Contrast-enhanced visual cryptography schemes based on block pixel patterns

Contrast-enhanced visual cryptography schemes based on block pixel patterns

Multitone reconstruction visual cryptography based on phase periodicity

The current no-computation grayscale image visual cryptography (VC) can only achieve halftone reconstruction but cannot truly achieve multitone. To solve this problem, we propose the concept of phase periodicity of the λ/2 retarder film and calculate the optical axis angle set with phase periodicity. According to the phase periodicity, we propose a λ/2 retarder film phase periodicity visual cryptography (RPP-VC). In RPP-VC, the secret pixels are encoded as the optical axis angles of nλ/2 retarder films and distributed to n shares. The decoding process does not require computation. The reconstructed image has no pixel expansion and can reach up to 23 tones. The quality of the reconstructed images has been greatly improved and the evaluation indicators of perceived quality are nearly doubled compared with other grayscale image VC schemes. The experimental results verify the feasibility of RPP-VC.

A Lossless-Recovery Secret Distribution Scheme Based on QR Codes

The visual cryptography scheme (VCS) distributes a secret to several images that can enhance the secure transmission of that secret. Quick response (QR) codes are widespread. VCS can be used to improve their secure transmission. Some schemes recover QR codes with many errors. This paper uses a distribution mechanism to achieve the error-free recovery of QR codes. An error-correction codeword (ECC) is used to divide the QR code into different areas. Every area is a key, and they are distributed to n shares. The loss of any share will make the reconstructed QR code impossible to decode normally. Stacking all shares can recover the secret QR code losslessly. Based on some experiments, the proposed scheme is relatively safe. The proposed scheme can restore a secret QR code without errors, and it is effective and feasible.

Proactive visual cryptographic schemes for general access structures

Proactive visual cryptographic schemes for general access structures

A robust VC scheme for securing cloud data storage

Visual Cryptography (VC) was created to encode images into several shares and decode them by aggregating the shares without the use of costly standard cryptanalysis. To enhance the quality and security of visual images in cloud storage, a Robust Collusion Avoidance-based Secure Signific VC (RCA-SSVC) scheme was designed, which creates the collusion-resistance Secret Image (SI) shares and embeds them into the Cover Image (CI) to prevent collusion threats. But it takes a long-time during access for users to recover the real image whenever receiving fake shares kept in the cloud by unauthorized users. Therefore, in this article, a new 2-level data protection scheme is proposed using QR code and RCA-SSVC. In this scheme, the public and private information of users are taken as QR code, which is encoded into sub-pixel blocks of all shares during the share creation phase. Also, a random permutation is applied to the created shares to disrupt the sub-pixels in a single block, which can avoid attackers from guessing the location of the Secret QR (SQR) code’s pixels. During the image restoration step, the restoration process is initiated once the user identity is authenticated by reading QR code information, which is matched with the QR code embedded in the shares. So, image restoration using illegitimate shares during access is prevented. At last, the test outcomes reveal that the RCA-SSVC-QR establishes maximum confidentiality in image access from the cloud storage compared to the classical VC schemes.

Improved Random Grid-based Cheating Prevention Visual Cryptography Using Latin Square

Visual cryptography scheme is a method of encrypting secret image into n noiselike shares. The secret image can be reconstructed by stacking adequate shares. In the past two decades, many schemes have been proposed to realize the cheating prevention visual cryptography scheme (CPVCS). Significantly, Ren et al. [ 9 ] first introduced the idea of CPVCS with the help of Latin square. Inspired by their work, in this article, a new reliable scheme is proposed. More precisely, to facilitate the certification process, we embed meaningful characters into the randomly chosen authentication patterns in each divided blocks. Furthermore, we fix the security vulnerability in the stacked results of share S g and verification Ver g , where 1≤ g ≤ n . Since the improved scheme encrypts the secret image by utilizing random grids, the generated shares have no pixel expansion. Finally, theoretical analysis and experimental results are conducted to evaluate the efficiency and security of the proposed scheme.