Encryption for network security

• Data sent over a network is vulnerable to interception. To protect the data, it is usually encrypted. This means that it cannot be understood if intercepted. This is especially important if data is sent over a public network, such as the Internet.
• Encryption can be used to make sure that data is unreadable if intercepted. An encryption algorithm is used to convert Plaintext into Ciphertext. 
• There are two main types of encryption algorithms – symmetric-key and asymmetric-key.
• Symmetric-Key Algorithms use one key to both encrypt and decrypt messages. Both parties must have access to this key.
• Asymmetric-Key Algorithms use different keys for encryption and decryption. The sender uses the recipient’s public key to encrypt the message. The recipient can then decrypt the message using their private key.
• Asymmetric encryption is slower, but allows the sender to be authenticated.
• Most computer systems today use asymmetric encryption to generate a symmetric key that is used to secure a limited communications session (so that the key is not in use for a long time).