Mobile payment is defined as mobile money, which is considered as an attractive alternative for cash,
cheque, or credit. In this paper we propose a new secure mobile paymentmethod. This method is
summarized in three processes: firstly, the authentication process, which involves the authentication phases
for the applied customers. Secondly, the member recognition process which tests and ensures the customer
membership by the market server. Finally, payment processwhich will be done by ciphering the customer
information using public-key encryption cryptosystem (RSA), to be submitted over an insecure network to
the market server. Actually, this mobile payment methodis more efficient than otherpayment methods since
the customer can pay from his/her own mobilephone without any extra cost and effort. The RSA public-key
encryption system ensures the security of the proposed method. However, to prevent a brute force attack,
the choice of the key size becomes crucial.