O'Reilly logo

CISSP For Dummies, 4th Edition by Peter Gregory, Lawrence Miller

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Cryptography Basics

Cryptography today has evolved into a complex science (some say an art) presenting many great promises and challenges in the field of information security. The basics of cryptography include various terms and concepts, the individual components of the cryptosystem, and the classes and types of ciphers.

Plaintext and ciphertext

A plaintext message is a message in its original readable format or a ciphertext message that has been properly decrypted (unscrambled) to produce the original readable plaintext message.

A ciphertext message is a plaintext message that has been transformed (encrypted) into a scrambled message that’s unintelligible. This term doesn’t apply to messages from your boss that may also happen to be unintelligible!

Encryption and decryption

Encryption (or enciphering) is the process of converting plaintext communications into ciphertext. Decryption (or deciphering) reverses that process, converting ciphertext into ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required