Mobile phones are considered to be the most common devices in history of humankind. They have involved in financial transaction such as mobile banking and mobile payment, which include sensitive information. Public key cryptography is the proven solution that can provide secure transaction at every point of interaction in mobile banking value chain. This paper proposes a need for peer-to-peer Strong Local Authentication Protocol (p2pSLAP) for Mobile Banking Transaction that implements a peer-to-peer architecture to provide local authentication mechanism between the customer and the agent. It employs public key infrastructure (PKI).