The ISC International Journal of Information Security

Abstract Preserving data confidentiality is crucial in today’s digital world where data exchange is increasingly becoming digital. This paper presents a novel text steganography algorithm. Initially, the secret message is converted into a bit stream. This bit stream is then shuffled using a random sequence to enhance security. Finally, the data is converted into a specific ”time” (including date and hour), and this generated time is embedded within a suitable cover text. The results demonstrate that the proposed algorithm is robust against a variety of attacks, including retyping, OCR, printing and photocopying, compression, document feature modification, non-Unicode environment conversion, and semantic paraphrasing. The algorithm is language-independent and applicable to all languages. The scheme exhibits high transparency against visual and machine attacks and has a capacity of 18 bits per time. The embedding of information bits using a random sequence enhances the scheme’s resistance against detection attacks.

Abstract The paper presents a novel approach to Secret Image Sharing (SIS) that combines (t, n)-threshold schemes with steganography, utilizing Joseph’s problem and Homogeneous Linear Recursion (HLR) to enhance security. The methodology involves dividing a secret image into shadow images, embedding these shadows into cover images using a Least Significant Bit (LSB) method guided by Joseph’s problem. The study aims to increase the security of SIS while maintaining high visual quality in the stego images. The authors validate their approach through various experiments, demonstrating that the proposed method improves Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM) compared to existing methods.

Abstract A multi-secret sharing scheme (MSS) allows a dealer to share multiple secrets among a set of participants. in such a way a multi-secret sharing scheme (MSS) allows a dealer to share multiple secrets among a set of participants, such that any authorized subset of participants can reconstruct the secrets. Up to now, existing MSSs either require too long shares for participants to be perfect secure, or do not have a formal security analysis/proof. In 2013, Herranz et al. provided the first formal definition of computational security for multi-stage secret sharing scheme (MSSS) in the standard model and proposed a practical and secure scheme. As far as we know, their scheme is the only computationally secure MSS in the standard model, and there is no formal definition of the computational security for other categories of MSSs. Based on this motivation, in this paper, we define the first formal model of indistinguishability against the chosen secret attacks (CSA) for other types of MSSs in the standard model. Furthermore, we present two practical CSA-secure MSSs, belonging to different types of MSSs and enjoying the advantage of short shares. They are also provably secure in the standard model. Based on the semantic security of the underlying encryption schemes, we prove the security of our schemes.