IN THIS CHAPTER
Understanding hashing and encryption
Checking file integrity
Encrypting files, directories, and filesystems
Understanding pluggable authentication modules
Managing Linux security with PAM
Due to ever changing and growing threats, implementing basic computer security is no longer enough. As malicious users gain access to and knowledge of advanced tools, so must a Linux systems administrator. Understanding advanced computer security topics and tools must be part of your preparation.
In this chapter, you learn about cryptography basics, such as ciphers and encryption. You also learn how the authentication module utility can simplify your administrative duties, even though it is an advanced security topic.
Using cryptography enhances the security of your Linux system and its network communications. Cryptography is the science of concealing information. It has a long and rich history that goes back far before computers were around. Because of its heavy use of mathematical algorithms, cryptography has easily transitioned to computers. Linux comes with many cryptographic tools ready for you to use.
To understand cryptographic concepts and the various Linux tools, you should know a few cryptography terms: