2.3 Encryption

By the end of this section you should be able to

• 2.3.1 Explain why data is encrypted before transmission
• 2.3.2 Describe symmetric encryption
• 2.3.3 Describe asymmetric encryption with public and private keys

Lessons

1. Encryption and symmetric keys
2. Asymmetric encryption
3. Cracking encryption (extension)

Key vocabulary

Encryption

Scrambling data so it cannot be understood if intercepted.

Plaintext

The original data before it is encrypted.

Ciphertext

Data after it has been encrypted.

Symmetric encryption

The same key is used to encrypt and decrypt the data.

Asymmetric encryption

A public key encrypts the data and a matching private key decrypts it.

Public key

A key that is shared openly and used to encrypt data.

Private key

A key kept secret by its owner and used to decrypt data.