The present invention relates to a method and a device for the fast verification of sector addresses in a data stream obtained from a recording medium upon a request from a microcontroller. According to the invention, the method comprises the steps of: reading the data stream from the recording medium; decoding the data stream to obtain a decoded data stream comprising user data and sector addresses; comparing the sector addresses with a range of valid sector addresses; and transmitting only user data having sector addresses within the range of valid sector addresses; whereby dedicated comparing means are provided for performing the comparing step independently of the microcontroller.