A Modified Multi-secret Visual Cryptography with Ring Shares

Abstract. A visual cryptography scheme encoding multiple secret images into two ring shares is proposed in this paper. In the secret sharing process, two shares are produced by the marked areas and the basis matrices of (2, 2)-VCS. Using ring shift right function, the secret images are recovered by stacking two shares. The security and contrast properties of the scheme have been proved. Compared with the previous ones, the scheme makes the number of secret images unlimited. Furthermore, the pixel expansion and the relative difference are improved greatly

CHARAKTERYSTYKA WYBRANYCH TECHNIK UKRYWANIA OBRAZU

Considering that different techniques of hiding images are known for a  long time, but have not found wider application, perhaps because of  their shortcomings. In this publication are described some types of techniques secret sharing images that are already in use. The author aims to review these techniques and  summarizes their features.Zważywszy, że różne techniki utajniania obrazów są znane od dawna, lecz nie znalazły szerszego zastosowania, być może ze względu na ich mankamenty, w tej publikacji zostaną opisane niektóre rodzaje technik sekretnego podziału obrazów, które już są. Autor ma na celu przeglądnięcie tych technik i ich podsumowanie

XOR-Based Progressively Secret Image Sharing

[[abstract]]Secret image sharing technology is a strategy for jointly protecting secret images. The (n, n) secret image sharing problem can be solved by conventional Boolean calculation easily. However, how to recover secret images with progressive steps is not addressed. In this study, we proposed an XOR-based (m, t, Ti) multi-secret image sharing scheme that shares m secret images among m participants and recovers m shared images progressively with t thresholds. The proposed secret images partition strategy (SIPS) partitions m secret images to generate intermediate images for different thresholds in the sharing procedure. Based on progressive recovery property, the proposed recovery method recovers parts of the secret images by gathering consecutive shared images. Moreover, gathering all shared images can perfectly recover all secret images. The experimental results show that the proposed XOR-based multi-secret image sharing method has high security and efficiency.[[notice]]補正完

Criptografía básica y algunas aplicaciones

Treball de Fi de Màster Universitari en Matemàtica Computacional (Pla de 2013). Codi: SIQ527. Curs 2021/2022 (A distància

Sharing Visual Multi-secrets Using Circle Shares

[[abstract]]Traditional visual cryptography technique has provided sufficient security to fulfill the purpose of protecting confidential messages. In current technology, the same set of shares can be embedded with many sets of secret messages after one of the shares is rotated at different degrees. However, the used share is rectangle so that only four kinds of angle variation exist when stacking shares. Thus, when intending to embed many sets of confidential messages by using these shares, the angle variation of rotating the shares is limited. This paper proposes an improved (2, 2)-visual secret sharing scheme that adapts circular shares to deal with the limitation of rotating angles in traditional visual cryptography. The primary property of the proposed technique is that two sets of confidential messages can be embedded in the same shares. After rotating one of the shares to a certain degree and stacking it with another share, the content of the second confidential message can be obtained. The share used in this technique is circular, where confidential data can be embedded in various different angle conditions. Compared with traditional visual cryptography, this technique has more flexibility, extensibility and security