<P>Through three editions, <B><I>Cryptography: Theory and Practice</B></I>, has been embraced by instructors and students alike. It offers a comprehensive primer for the subject¿s fundamentals while presenting the most current advances in cryptography.</P><P>The authors offer comprehensive, in-depth treatment of the methods and protocols that are vital to safeguarding the seemingly infinite and increasing amount of information circulating around the world.</P><P><B>Key Features of the Fourth Edition:</P><UL></B><P><LI>New chapter on the exciting, emerging new area of post-quantum cryptography (Chapter 9).</LI><P></P><P><LI>New high-level, nontechnical overview of the goals and tools of cryptography (Chapter 1).</LI><P></P><P><LI>New mathematical appendix that summarizes definitions and main results on number theory and algebra (Appendix A).</LI><P></P><P><LI>An expanded treatment of stream ciphers, including common design techniques along with coverage of Trivium.</LI><P></P><P><LI>Int