Known-Plaintext Attack
In the known-plaintext attack model the adversary holds several plaintext-ciphertext pairs (P_i, C_i) and exploits their relation to recover the key or decrypt new ciphertexts.
Purpose
It evaluates cipher security when the attacker already knows parts of the traffic (e.g., fixed protocol headers).
Mechanism
The adversary holds pairs (P_i, C_i = E_K(P_i)) and tries to derive K or decrypt other ciphertexts. Linear and differential analyses typically work in this model.
Use cases
- Model for linear/differential analysis
- Fixed protocol header leakage assessment
- Cipher security analysis