In this paper we present SRDP-sign, a reliable multicast protocol designed to guarantee the reliable transmission of short messages via satellite as an extension of satellite reliable distribution protocol (SRDP). The uses of this protocol range from sending short text messages to transmitting information used for the improvement of networkspsila performances. The innovation of this protocol is that it has a high degree of scalability, reduced communication with receivers and fast delivery. In this paper we show the operations of the protocol, the underlying algorithms and analyse the protocolpsilas behavior.