Abstract: A method and system for providing conditional access (CA) between a headend and a receiver include scrambling media data of broadcast programs and encrypting control words according to a CA system used on the headend. The receiver includes a CA virtual machine. The receiver receives the broadcast program and encrypted control words, and determines whether the media data is scrambled. If the media data is scrambled, the CA virtual machine runs a CA instance matched with the CA system, gets entitled manage message (EMM), and determines whether CA algorithm identifier in the EMM matches with CA algorithm identifier of the CA instance. If the CA algorithm identifiers match, the encrypted control words are decrypted and the scrambled media data is descrambled. If the CA algorithm identifiers do not match, updated CA algorithm is downloaded and the CA instance which has updated its CA algorithm is run.

Abstract: A universal serial bus (USB) drive includes a control button, a control signal generating circuit, a flash memory, a connection port, a processor, and an indication lamp. The USB drive generates a removal instruction from a connection device, according to a user operation thereon. The USB drive determines whether the flash memory is in a working state and controls the connection port to disconnect from the connection device, if the flash memory is not in the working state. The indication lamp on the USB drive provides a notification that the connection port is disconnected from the connection device.