Young, A.L. <br/><br/>
Mathematical ciphers  From caesar to RSA 
A. L. Young 
 - Providence  American Mathematical Society  2006 
 - viii  159 
 - Mathematical world 25 .
<br/><br/><label>ISBN: </label>9780821837306 
<br/><br/><label>Dewey Class. No.: </label>2.09  / YOUN