CHAPTER 2 - Data Security

Abstract

Data exchange and data storage are common processes that everyone uses. The data is usually categorized as unclassified and classified. Unclassified data can be accessed by anyone without restrictions; whereas unintended third parties cannot access classified data. There are cryptography techniques that are used to protect classified data from unintended observers or eavesdroppers. Using cryptographic techniques one can make the information unintelligible to people who do not have a need to know or who should not know. The basic cryptographic module consists of a secret key and a mathematical algorithm. The cryptographic process of converting plain text to unintelligent form (termed as cipher text) is called encryption. The inverse process of converting cipher text to plain text is called decryption. In addition, a cryptographic technique also allows to transmit or to store the classified data in a secure manner. In this process, a cryptographic (or mathematical) algorithm can be in the public domain, but the cryptographic (or secret) key should not be disclosed to the public. Furthermore, cryptographic algorithms are broadly divided into three categories: symmetric key algorithms, public-key algorithms, and hash functions based algorithms.