infosec principles

The basic components of information security are most often, referred as CIA triad:

Confidentiality, Integrity, and Availability.

• Confidentiality is perhaps the element of the triad that most immediately comes to mind when you think of information security. Data is confidential when only those people who are authorized to access it can do so; to ensure confidentiality, you need to be able to identify who is trying to access data and block attempts by those without authorization. Passwords, encryption, authentication, and defense against penetration attacks are all techniques designed to ensure confidentiality.

• Integrity means maintaining data in its correct state and preventing it from being improperly modified, either by accident or maliciously. Many of the techniques that ensure confidentiality will also protect data integrity—after all, a hacker can't change data they can't access—but there are other tools that help provide a defense of integrity in depth: checksums can help you verify data integrity, for instance, and version control software and frequent backups can help you restore data to a correct state if need be. Integrity also covers the concept of non-repudiation: you must be able to prove that you've maintained the integrity of your data, especially in legal contexts.

• Availability is the mirror image of confidentiality: while you need to make sure that your data can't be accessed by unauthorized users, you also need to ensure that it can be accessed by those who have the proper permissions. Ensuring data availability means matching network and computing resources to the volume of data access you expect and implementing a good backup policy for disaster recovery purposes.