Software protection and identification system

A computer system, comprising:

• an authorized magnetic information recording disk having a uniform high coercivity magnetic coating and including data to be protected form unauthorized use, signals recorded on said authorized disk being alterable only be a magnetic field having an intensity greater than a first intensity;
• means for reading information stored on said disk;
• means for writing information on said disk, said writing means capable of producing a magnetic field not greater than a second intensity less than said first intensity, said second intensity being at least a predetermined amount less than said first intensity;
• means for attempting to write with said writing means predetermined digital signals on a disk presented for use with said computer system;
• means for comparing said predetermined digital signals to information read by said reading means from said presented disk;
• and
• means responsive to said comparing means for disabling said computer system if information read from said presented disk equals said predetermined digital signals.

A method of protecting against the unauthorized duplication and use of computer software, comprising the steps of:

• providing an authorized storage medium having a uniform high coercivity magnetic coating, said coating having a magnetic coercivity greater than or equal to a first coercivity;
• recording validating signals on said authorized storage medium with a magnetic field strength greater than or equal to a first magnetic field strength;
• recording computer software on said authorized storage medium;
• attempting to alter said validating signals on a magnetic storage medium presented for use in a computer system with a writing means associated with said computer system;
• reading signals corresponding to said validating signals on said presented magnetic storage medium;
• and
• disabling said computer system to prevent use of said computer software if said validating signals are not read by said computer system,
• whereby a computer system having writing means which cannot provide a field strength about the same as said first magnetic field strength will be disabled.