Content reproduction system, information processing terminal, media server, secure device, and server secure device

A content reproduction system includes an information processing terminal (102) and a secure device (103). The information processing terminal (102) receives a copyright protection application program (315) from an application distribution server (113). The copyright protection application program includes a first program having a first execution format executable in the information processing terminal (102) and a second program having a second execution format different from the first execution format and executable in the secure device (103). The second program is encrypted with a program key (515) held in the secure device (103). By extracting and executing the first program, the information processing terminal (102) extracts the second program and transmits the second program to the secure device (103). The secure device (103) receives the second program from the information processing terminal (102), decrypts the second program using a program key stored in a key storing unit (520), and executes the second program.