Chapter 7: Cryptography Basics and Methods

The Following Comptia Security+ Exam Objectives are Covered in this Chapter:

• 1.4 Attacks

  • 1.4.7 Weak Keys

  • 1.4.8 Mathematical

  • 1.4.10 Birthday

• 4.1 Algorithms

  • 4.1.1 Hashing

  • 4.1.2 Symmetric

  • 4.1.3 Asymmetric

• 4.2 Concepts of Using Cryptography

  • 4.2.1 Confidentiality

  • 4.2.2 Integrity

    • 4.2.2.1 Digital Signatures

  • 4.2.3 Authentication

  • 4.2.4 Non-Repudiation

    • 4.2.4.1 Digital Signatures

  • 4.2.5 Access Control

• 4.3 PKI

  • 4.3.1 Certificates – Make a distinction between what certificates are used for what purpose. Basics only.

    • 4.3.1.1 Certificate Policies

    • 4.3.1.2 Certificate Practice Statements

  • 4.3.2 Revocation

  • 4.3.3 Trust Models

Cryptography (the art of concealing information) is an area of high interest to governments, to businesses, and increasingly to individuals. People want privacy when it comes to personal and other sensitive information. Corporations want to protect financial records, trade secrets, customer lists, and employee information. The government uses cryptography to help ensure the safety and well-being of its citizens.

Throughout history, the lack of secrecy in governmental communications has cost many lives, caused wars, and toppled governments. Entire governmental agencies have been created to help ensure secrecy, and fortunes have been spent trying to protect national secrets and trying to learn the secrets of other countries.

Individuals who specialize in the development and making of codes are referred to as cryptographers. Individuals who specialize in breaking codes are called cryptanalysts. Many of these professionals are geniuses with strong backgrounds in math and computer science. They live in a world all their own, and they can't talk about what they do.

This chapter discusses the various forms of cryptography and how they are used in the computer field. Your private information must be protected from unauthorized access and exploitation. Your data must be protected. The primary method of protecting your data from prying eyes is cryptography.

This chapter includes a brief overview of cryptography, and it discusses some of the more common algorithms used, how encryption is used today, Public Key Infrastructure, and some of the attacks to which cryptographic systems are vulnerable.