Threshold Cryptosystem and Its Application in Subliminal Channel Scheme

This paper analyzed the basic principles of secret sharing in threshold cryptosystem and its superiority for application in subliminal channel schemes. Considering the security threats and system flaws of present subliminal channel schemes, we present a threshold subliminal channel scheme based on ECC(elliptic curve cryptosystem). By utilizing secret key sharing the scheme achieves threshold management of subliminal message generating and recovering; the subliminal message can only be generated and recovered by no less than t valid members. The identity blinding and probabilistic encryption algorithms enable the protocol parties to be anonymous for secrecy protection and the anonymity can also be revoked conveniently if necessary. The threshold tracing algorithm ensures the identity tracing right can only be executed by no less than t valid members. The scheme renders effective supervision on subliminal message and identity secrecy. The application case of the subliminal channel scheme further justifies its brevity, security, high efficiency regarding its application in software and hardware environment.