Symmetric encryption systems

Question 1

What is a symmetric encryption system?

Answer 1

can be used to encrypt and decrypt data with a secret key. Encryption: maps a plaintext M to a ciphertext C
Decryption: maps a ciphertext C to a plaintext M

Question 2

Name the 5 components of a symmetric encryption system

Answer 2

• plaintext M
• ciphertext C
• key K
• family E (encryption function)
• family D (decryption function)
• -> E and D have to be inverse to each other