00438nam a2200157 a 450000500170000002000150001708200170003210000220004924500410007125000120011226000390012430000260016350000530018970000190024270000190026120251203110646.0  a8173666830  a005.432bGAR  aGarfinkel, Simson  aPractical Unix and Internet Security  a3rd ed.  aNew DelhibShroff Publishersc2003  axxix,956p.c24 cm. PB  aExtensively Revised Over 250,000 Copies in Print  aSpafford, Gene  aSchwartz, Alan