Enhanced halftone-based secure and improved visual cryptography scheme for colour/binary Images

• Published in: Multimedia tools and applications 2021-09, Vol.80 (21-23), p.32071-32090
• Main Authors: Ahmad, Saleha, Hayat, Muhammad Faisal, Qureshi, Muhammad Ali, Asef, Shahzad, Saleem, Yasir
• Format: Article
• Language: English
• Subjects: Algorithms; Color imagery; Computer Communication Networks; Computer Science; Cryptography; Data Structures and Information Theory; Encryption; Handwriting; Image enhancement; Image restoration; Multimedia Information Systems; Printed text; Special Purpose and Application-Based Systems
• ISSN: 1380-7501; 1573-7721
• DOI: 10.1007/s11042-021-11152-z

Visual Cryptography (VC) is gaining attraction during the past few years to secure the visual information in the transmission network. It enables the visual data i.e. handwritten notes, photos, printed text, etc. to encrypt in such a way that their decryption can be done through the human visual framework. Hence, no computational assistance is required for the decryption of the secret images they can be seen through naked eye. In this paper, a novel enhanced halftoning-based VC scheme is proposed that works for both binary and color images. Fake share is generated by the combination of random black and white pixels. The proposed algorithm consists of 3 stages i.e., detection, encryption, and decryption. Halftoning, Encryption, (2, 2) visual cryptography and the novel idea of fake share, make it even more secure and improved. As a result, it facilitates the original restored image to the authentic user, however, the one who enters the wrong password gets the combination of fake share with any real share. Both colored and black images can be processed with minimal capacity using the proposed scheme.