On the Security of Black-Box Implementation of Visual Secret Sharing Schemes

Cryptographic software and devices give users the ability to take advantage of the benefits of cryptography more easily. However, this implies that the users must totally trust the manufacturer and the authenticity of the device or software they use. Young and Yung were the first to question the correctness of the manufacturer and considered the advantage that a malicious implementation could offer to a specific attacker. In this paper, we consider a modified version of two visual secret sharing schemes and the advantage that they provide to the attacker in order to reconstruct the secret by himself, while the other participants must fulfill the honest scheme reconstruction conditions. We also analyze the security of the proposed mechanisms and the conditions in which they can be applicable.