00322    a2200121   4500020001800000082001500018100002100033245004500054260003600099300002400135650001800159700002300177  a9780072976045  a005.8bCAR  aCarr, Houston H.  aData communications and network security  aBostonbMcGraw-Hillc2007g2007  axxxiv, 526p.c26cm.  aDATA SECURITY  aSnyder, Charles A.