Throughout this course, there'll be one key acronym to keep in mind, the CIA. No, I'm not talking about the U.S. Central Intelligence Agency, although they do have a lot to do with national security. When I say CIA, I'm talking about confidentiality, integrity, and availability. These three key principles are the foundation for what's widely referred to as the CIA triad, a guiding model for designing information security policies. These three principles will help you develop security policies in the workplace and for your own personal environments. Let's start with confidentiality. Confidentiality means keeping things hidden. In I.T., it means keeping the data that you have hidden safely from unwanted eyes. One particular method of confidentiality that you probably use everyday is password protection. Only you, maybe your partner, should know the password to gain access to your bank account online. For confidentiality to work, you need to limit access to your data. Only those who absolutely need to know how to gain access, should. The I in CIA stands for integrity. Integrity means keeping our data accurate and untampered with. The data that we send or receive should remain the same throughout its entire journey. Imagine if you downloaded a file off the Internet, and the website you're downloading it from, says the file is three megs. Then, when you download it, it turns out to be about 30 megs. That's a red flag. Something happened during the download, something potentially unsafe. An unwanted file may now be living on your hard drive. As you'll learn in a later lesson, this happens all too often. Last but not least. Let's look at the A in CIA, which stands for availability. Availability means that the information we have is readily accessible to those people that should have it. This can mean many things, like being prepared if your data is lost or if your system is down. Security attacks are designed to steal all kinds of things from you, time, material things, your dignity. Some steal the time that you'll need to spend to get services back up and running. Some security attacks will hold your system hostage, until you pay a ransom for it. Sounds scary and it is but that's why you're here, to learn how to stop these types of attacks from happening. Going through this course, you'll see how every aspect of security revolves around these three key principles: confidentiality, integrity and availability.