A method is provided for preventing a peripheral device such as an ATA disc drive, which is restricted to use with a designated host, being hot-plugged to another system after the drive is unlocked. Thus, violation of privacy of data (eg. music/video) stored on the drive through a hot-plug attack may be avoided. This is accomplished by maintaining time synchronization between the drive and its designated host so that both devices obtain the same seed from time information to generate a validation number at any time that a read/write command is issued from the host.