Encryption Technologies

You may work for a super-secret government agency, or you may be just a regular Joe or Jane citizen. Either way, you still have sensitive data that you need to protect from prying eyes. Business secrets, government secrets, personal secrets—it doesn’t matter. It all needs protection. Locking down users’ home directories with restrictive permissions settings, as we saw in Chapter 3, Securing Normal User Accounts, is only part of the puzzle; we also need encryption. This encryption will provide three things for us:

• Confidentiality: This ensures that only people who are authorized to see the data can see it.
• Integrity: This ensures that the original data haven’t been altered by unauthorized people.
• Availability: This ensures that sensitive data are always available, and can’t be deleted by unauthorized people.

The two general types of data encryption that we’ll look at in this chapter are...