Securing micropayment transactions over Session Initiation Protocol

Session Initiation Protocol (SIP) is gaining more acceptability as a standard for voice over IP (VoIP). Several payment protocols were proposed for SIP. However, they lack necessary security properties and have poor performance due to cryptographic operations chosen. In this paper, we introduce SIPTOP, a SIP token-based micropayment protocol that operates well in SIP environment. Moreover, we propose a new authentication protocol for SIP. SIPTOP was analyzed to guarantee its security properties and acceptable transaction performance.