METHOD FOR TEMPORARILY ERASING DATA STRING, RESTORING METHOD, METHOD FOR QUICKLY AND PERMANENTLY ERASING TEMPORARILY ERASED DATA STRING AND RECORDING MEDIUM WITH ADDITIONAL INFORMATION FOR RESTORING OR PERMANENTLY ERASING TEMPORARILY ERASED DATA STRING STORED THEREON

摘要

PROBLEM TO BE SOLVED: To completely restore data strings separated with temporary erasure by storing 1st additional information showing that a data string corresponding to a temporary erasure section is temporarily erased and 2nd additional information showing that a permanently erasable area where permanent erasure is performed in the data string to which the 1st additional information is added exists in search information. SOLUTION: The additional information of search information shows that a cell where a TE flag includes the information is temporarily erased, that a cell where a PE flag is temporarily erased includes a permanently erasable data string unit (SOBU), that an EP-S-SOBU (Start SOBU of the Entry point for Erasing) shows the first one among permanently erasable data string units, and that an EP-E-SOBU) (End SOBU of the point for Erasing) shows the last one among the permanently erasable data string units.