Patterned-media magnetic recording disk with cryptographically scrambled patterns and disk drive operable with the disk

A patterned-media magnetic recording disk drive having a magnetic recording disk, a read head, a write head, and an actuator connected to the read head and write head for moving the heads across the disk, the disk drive comprising:

• a patterned-media perpendicular magnetic recording disk having a plurality of generally concentric circular data tracks, each data track containing discrete magnetizable data islands grouped into data sectors, a plurality of magnetized nondata synchronization marks between the data sectors for synchronizing the reading and writing of data in the data islands of the data sectors, and nondata regions containing a pattern of nonmagnetic gaps and magnetized nondata islands representing a scrambled track identification (TID) number, the nondata islands in said pattern being magnetized in the same direction;
• a data controller for selecting the data track and data sector where data is to be read or written;
• a read head for detecting the synchronization marks and reading the scrambled TIDs;
• and
• electronics for descrambling the scrambled TIDs read by the read head and for controlling the actuator to move the read head to the selected data track.

A patterned-media magnetic recording disk drive having a magnetic recording disk, a read head, a write head, and an actuator connected to the read head and write head for moving the heads across the disk, the disk drive comprising:

• a patterned-media magnetic recording disk having a plurality of generally concentric circular data tracks, each data track containing a track identification (TID) number, discrete magnetizable data islands grouped into data sectors, and a plurality of magnetized nondata synchronization marks between the data sectors for synchronizing the writing of data in the data sectors, each synchronization mark being associated with a data sector, and wherein the spacing between a synchronization mark and its associated data sector in a track represents a scrambled phase shift number for the data sector;
• a data controller for selecting the data track and data sector where data is to be written;
• a read head for detecting the synchronization marks;
• a hash function having a secret key, the hash function providing a pseudo-random phase shift number for the data sector of the selected data track in response to the secret key and the TID of the selected data track;
• a write head for generating write pulses to magnetize the data islands in the data sectors;
• a write clock coupled to the write head for controlling the write pulses to the data islands;
• and
• a compensator for generating a phase adjustment signal to the write clock in response to the pseudo-random phase shift number from the hash function.