A secure mobile financial transaction is provided by receiving, over a communication network, a list of protection mechanisms available for implementation by an external terminal. Security-related data is received from one or more sensors and an attack signature is computed based on the security-related data. An appropriate security policy is selected from multiple security policies stored in a database based on the list of protection mechanisms and the attack signature. A secure communication session is established between the external terminal and an internal network component according to the selected security policy. A data message associated with a mobile financial transaction is communicated over the communication network during the communication session.