Singh, Simon. <br/><br/>
The code book :  the secret history of codes and code-breaking / 
Simon Singh. 
 - London :  Fourth Estate,  2000, c1999. 
 - 400 p. :  ill. ;  20 cm. 
<br/><br/> Originally published: 1999. 
<br/><br/><label>ISBN: </label>9781857028898 (pbk.) 
<br/><br/><label>Nat. Bib. No.: </label>GBA0X5928 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cryptography.<br/>Cryptography--History.<br/>Ciphers.<br/>Data encryption (Computer science)<br/>Confidential communications.
<br/><br/><label>LC Class. No.: </label>Z104 
<br/><br/><label>Dewey Class. No.: </label>652.8