Formal analysis of SEP protocol using the interpretation function-based method

Electronic payment is the very important step of the electronic business system, and its security must be ensured. The Secure Electronic protocol (SEP) [1] was proposed to protect online payment transactions against the fraud without involving the third party such as Visa or MasterCard. SEP protocol avoids the complexities relating to the implementation unlike SET and 3D-secure, integration and utilization are also easier than before. Then it´s crucial to ensure that this protocol respect security properties such as confidentiality, authentication and integrity. In this paper, we analyze the SEP protocol with respect to the confidentiality (secrecy) property. To perform this analysis, we use the interpretation functions-based method [2, 3]. The main idea behind the interpretation functions-based technique is to give sufficient conditions that allow to guarantee that a cryptographic protocol respects the secrecy property. The flexibility of the proposed conditions allows the verification of daily life protocols such us SEP.