Symmetric Key Encryption
Triple DES (3DES)
- Applies DES three times to encrypt
- With 3 keys, get 168-bit effective key length
- Encrypt block with first key
- Decrypt (yes, decrypt) result with second key
- Encrypt result with third key; Send this ciphertext
- Decryption
- Decrypt ciphertext with third key
- Encrypt (yes, encrypt) result with second key
- Decrypt result with third key