Mollin, Richard A <br/><br/>
Codes : the guide to secrecy from ancient to modern times 

 - Boca Raton  Chapman & Hall/ CRC  2005 
 - xx, 679p.   
<br/><br/> Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>1584884703 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer security<br/>Cryptography<br/>Data encryption(Computer science)<br/>E-mail and internet security<br/>Key management<br/>Public-key cryptography