Declassifying Disks Holding Classified Info.

[Tom Bobowicz]

Does anyone know of DoD approved methods/procedures/software that can be
used to wipe clean a SUN workstation disk that has been used to store DoD
classified information at the SECRET level?  Essentially a reformatting
procedure that writes several different successive byte patterns to each
disk sector is required.  Any information or pointers in the right
direction would be greatly appreciated.

Thanks in advance.