Device, system, and method of executing secure-processing (SEP) applications. Some demonstrative embodiments include a secure-processing (SEP) hardware module including a processor capable of executing at least one SEP application, wherein the SEP hardware module is configured to perform at least one of encrypting and decrypting data handled by the SEP application using an application-specific application-key corresponding to the SEP application, only if the processor begins execution of the SEP application at an approved entry point of the SEP application, and wherein the application-key corresponding to the SEP application is based at least on an internal key internally stored by the SEP hardware module and on application-specific information corresponding to the SEP application. Other embodiments are described and claimed.