From the course: IT Security Foundations: Core Concepts

Providing data confidentiality

From the course: IT Security Foundations: Core Concepts

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Providing data confidentiality

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- [Instructor] Encryption is the best way to maintain confidentiality, as it scrambles data into an unreadable format using an algorithm and a key. In this segment, we'll cover the two types of encryption: symmetric and asymmetric. When dealing with encryption, you'll also hear the term "cipher," which is a code that uses a secret key in order to conceal data. Encryption is when we take a block of plaintext and convert it into ciphertext. And decryption is when we take a block of ciphertext and convert it back into plaintext. Now, let's look at an example of what encrypted text looks like. I'm here at this website where we first need to select an algorithm to encrypt our text. I'll drop this down. There are plenty to choose from, but I'll select DES. Over here for modes, again, there's lots to choose from, but I'll select cipher block chaining. Here I've entered my secret key, and there's my block of plaintext. I'll say "Encrypt." Now down below, these are HTML tags for a webpage, and we don't need those, so I'll strip those out. And there's your ciphertext, and as you can see, you can't read the text unless you have a key, so let's reverse the process. I'll select the ciphertext, and we'll put it up here. And using the same settings, I'll say "Decrypt." Again, I'll strip out the tags, and there you see your plaintext. Now that we understand how encryption conceals data, let's talk about the two types of encryption. We'll start with symmetric encryption, which uses a single shared key to encrypt data. Now, when using symmetric encryption between two entities, both parties must have the same shared key before it can be used to encrypt or decrypt data. Symmetric encryption is used for confidential online communications, for example, when using HTTPS. Symmetric algorithms include DES and AES. Now let's talk about asymmetric encryption, which uses two keys, a public key and a private key, which are mathematically related. When using asymmetric or public key encryption, two keys are generated, a private key and a public key. Now, the private key is kept private and never shared with anyone, and the public key is made public and shared with everyone. Asymmetric algorithms include RSA and PGP. Uses for asymmetric encryption include creating a digital signature, providing confidentiality, and securely exchanging a secret key. Both symmetric and asymmetric encryption have advantages. However, in most cases, we use a hybrid system, using both types of encryption to secure and exchange data. Now, let's test your knowledge. Explain the difference between symmetric and asymmetric encryption. You can record your answer on the challenge worksheet.

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