Substitution cipher:
- changes the value of plaintext without changing their positions.
Transposition cipher:
- does not change the value, but changes its position.
Substituition ciphers: mono and polyalphabetic.
- Monoalphabetic use a fixed substitution strategy - the substitution does not change if the position of the plaintext alphabet changes.
- Polyalphabetic use a variable substitution strategy - the substitution for a plaintext can be different depending on its position.
Index