Design and accountability analysis of a secure SMS-based mobile payment protocol

Nowadays, most of mobile payment transactions are made through Short Message Service (or SMS). A number of SMS-based mobile payment protocols have been proposed but still lack of necessary security properties. This paper introduces a new SMS-based operator-assisted mobile payment protocol called SOMP. The proposed protocol offers clients the ability to perform payment transactions directly to the mobile operator itself or to merchants through the mobile operator. We perform accountability analysis to show that SOMP satisfies necessary security properties. Moreover, SOMP is easy to use and compatible with existing SMS infrastructure.