The title of this book Cryptography and Network Security " A Ethics to Preserve Our Network & Data " This book covers the basics of the science of cryptography. It explains how programmers and network professionals can use cryptography to maintain the privacy of computer data. Starting with the origins of cryptography.Cryptography, which translates as "secret writing," refers to the science of concealing the meaning of data so only specified parties understand a transmission's contents. Cryptography has existed for thousands of years.