Systems and methods to provide and maintain secure financial transaction conducted with a credit card or other cashless payment mechanism at a vending machine or other potentially unattended vending or point of sale device. Encapsulated card readers providing end-to-end encryption capabilities encrypt transaction data for secure transmission to a transaction host or server. Pre-authorization transaction data checking maintains account numbers in a secure encrypted format further enhancing security. Protection mechanisms that guard against, and provide warnings of equipment tampering, while also providing a visual indication to customers regarding the security of the system.