The evolution of wireless networks and mobile devices has resulted in increased concerns about performance and security of mobile payment systems. In this paper we propose a new secured architecture for two-party mobile payments, e.g. mobile banking. The proposed architecture employs a lightweight cryptography system that combines public key and symmetric key cryptography systems (ECDSA and AES), as well as a multi-factor authentication mechanism. These are coupled with a transaction log strategy to satisfy the properties of confidentiality, authentication, integrity and non-repudiation. Compared to some existing mobile payment platforms the proposed architecture is a lightweight secured mechanism that is more suitable for two-party banking transactions over resource-limited mobile devices.