This paper proposes a novel electronic monetary transaction scheme that provides secure access to a set of mobile payment services for “unbanked” consumers equipped with mobile handsets. It considers a realistic scenario of a remittance service, i.e., a user-to-user transfer of funds, in which users do not necessarily trust intermediate parties (called agents) or their infrastructures and therefore require end-to-end security and privacy protection. Since the payment solutions market is very fragmented, we also assume that users and agents are subscribed to different payment solution providers. The paper proposes a holistic approach to securing payment services by focusing on securing the transaction rather than requiring users to authenticate with unknown agent infrastructures and by using a mechanism of delegation of trust. It also proposes a novel security approach for securing payment transactions over insecure communication channels based on the Identity Based Authenticated Key Exchange (IBAKE). © 2011 Alcatel-Lucent.