Insight into collusion attacks in random-grid-based visual secret sharing
Visual secret sharing (VSS), either visual-cryptography-based (VC-based) VSS or random-grid-based (RG-based) VSS, is a well-known technology of secret communication for sensitive security applications. Horng et al. (2006) kindled the interest in the cheating problem existing in threshold VC-based VSS. The cheating problem happened when dishonest participants collude to cheat honest ones by enabling the latter to accept the wrong secret information generated by the former. As RG-based VSS (RGVSS) has gained significant attention in academia in the past years, it is concerned that RG-based VSS may also suffer cheating attacks. The authors of the present study demonstrate that the security risk does exist in RG-based VSS. To prove the feasibility of cheating, the experimental results and formal analysis illustrate that the proposed collusion attacks do work.
collusion attack visual secret sharing cheating problem random grids