Changing the Threshold in a Bivariate Polynomial Based Secret Image Sharing Scheme

Mathematics

Shancang Li¹  Yanxiao Liu²  Houbing Song³  Qindong Sun⁴  Han Cao⁵ 

[1] Department of Computer Science and Creative Technologies, University of the West of England, Bristol BS16 1QY, UK;Department of Computer Science and Engineering, Xi’an University of Technology, Xi’an 710048, China;Department of Electrical, Computer, Software and Systems Engineering, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114, USA;School of Cyber Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China;Shaanxi Key Laboratory of Network Computing and Security, Xi’an University of Technology, Xi’an 710048, China;

关键词: secret sharing scheme;    secret image sharing;    threshold changeable;    bivariate polynomial;   

DOI  :  10.3390/math10050710

来源: DOAJ

【 摘 要 】

Secret image sharing (SIS) is an important application of the traditional secret sharing scheme, which has become popular in recent years. In an SIS scheme, a confidential image is encrypted into a group of shadows. Any set of shadows that reaches the threshold can reconstruct the image; otherwise, nothing can be recovered at all. In most existing SIS schemes, the threshold on shadows for image reconstruction is fixed. However, in this work, we consider more complicated cases of SIS, such that the threshold is changeable according to the security environment. In this paper, we construct a $(k\leftrightarrow h,n)$ threshold-changeable SIS (TCSIS) scheme using a bivariate polynomial, which provides $h-k+1$ possible thresholds, $k,k+1,\dots ,h$. During image reconstruction, each participant can update their shadow according to the current threshold T based only on their initial shadow. Unlike previous TCSIS schemes, the proposed scheme achieves unconditional security and can overcome the information disclosure problem caused by homomorphism.

【 授权许可】

Unknown