Method for activating a file on a navigation system

Method in which firstly a user inputs first and second encryption codes (PIN, ACW) into the navigation system. The codes are converted to vectors. The device identifier (ID) of the navigation system and the first encryption code are used to calculate a key (k). The key and the second encryption code are used to calculate an access code (AD), which is compared with a value stored in system memory. If there is agreement, the required files are decoded and enabled for use by the navigation system.