(ε, 0)-Secure Message Transmission

In Secure Message Transmission (SMT) protocol a sender S can send a message m to a receiver R in a ‘private’ and ‘reliable’ way. S and R are connected by n channels where at most t of them can be fully controlled by an adaptive adversary with unlimited computational power. In this paper, noting the similarity between the privacy goal of SMT and an encryption function, we introduce a new definition for privacy of SMT systems which is inspired by the definition of semantic security in encryption. We show the relationship between this new definition and the previously known one, and propose an efficient 1-round protocol that is secure under the new definition and insecure under the previous one. The protocol has a better transmission rate compared to all known 1-round protocols in the previous model. We discuss our results and show how it relates to known results in this area.