Cryptanalysis of RSA Factorization - Library(ISI Kolkata) - Indian ...
Cryptanalysis of RSA Factorization - Library(ISI Kolkata) - Indian ...
Cryptanalysis of RSA Factorization - Library(ISI Kolkata) - Indian ...
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Chapter 1<br />
Introduction<br />
The word ‘Cryptology’ originates from the Greek root words ‘kryptós’ (hidden)<br />
and ‘logia’ (study). So, quite literally, cryptology is the study and practice <strong>of</strong><br />
hiding information, that is, the art and science <strong>of</strong> information security. It is quite<br />
natural that the notion <strong>of</strong> security requires the presence <strong>of</strong> an adversary, and any<br />
system must be tested against all potential attacks. Based on this idea, cryptology<br />
has been branched into two parts - Cryptography and <strong>Cryptanalysis</strong>. While<br />
cryptography ensures secure communication between two parties over insecure<br />
communication channels (telephone, courier, fax, e-mail etc.), the field <strong>of</strong> cryptanalysis<br />
deals with the study <strong>of</strong> breaking a cryptographic scheme by obtaining the<br />
classified information without authorization.<br />
Cryptology was used vastly in ancient civilizations throughout the world.<br />
Around 3000 BC, the Egyptians could communicate securely by writing messages<br />
in the coded Hieroglyph. ‘Artha-Sastra’ by the renowned <strong>Indian</strong> politician Kautilya<br />
(350–283 BC) discussed the use <strong>of</strong> cryptology in political circles. Julius<br />
Caesar (100–44 BC) used the Caesar cipher to send confidential messages.<br />
The subject resurrected and evolved in a completely new form at the dawn <strong>of</strong><br />
the modern information era. During World War II, cryptology gained much more<br />
importance in political affairs. It was the famous episode <strong>of</strong> Enigma that made the<br />
worldaware<strong>of</strong>thepotentialpower<strong>of</strong>thesubject. Today, cryptologyhasearnedits<br />
repute as a prime branch <strong>of</strong> modern science that deals with information security<br />
issues in the arena <strong>of</strong> digital globalization. It is used for numerous purposes <strong>of</strong><br />
everyday life, including Internet banking, identification cards, secure databases,<br />
e-mails, social networking, and many more.<br />
1