Page 114 - CISSO_Prep_ Guide

Cryptography and Digital Signatures

Cryptography is the art and science of protecting the
confidentiality and integrity of data. Through the use of
cryptography, it is possible to protect data when stored or
transmitted, even when it is being transmitted over insecure
mediums such as radio, satellite, and the internet.

The five main benefits of cryptography are:
1. Confidentiality - keeping sensitive data private

2. Integrity - maintaining the accuracy of data
3. Access Control - preventing access by unauthorized users

4. Non-repudiation - linking activity to a known entity
(individual or process)

5. Authenticity - being able to ensure the identities of the
source and destination entities - knowing who sent what
and validating the destination

Not all of these benefits are available through all types of
cryptography. Various types of cryptographic algorithms and
implementations offer different services. The security
professional needs to know which benefits are provided by which
type of implementation.
The key definitions associated with cryptography are:
• Plaintext/cleartext - the message in its normal readable
format.
• Ciphertext/cryptogram - the message in an unreadable
format
• Encrypt/encipher.encode - the process of converting
plaintext into ciphertext