In [[cryptography]], '''Keykey clustering''' is said to occur when two different [[key (cryptography)|keys]] generate the same [[ciphertext]] from the same [[plaintext]], using same or different[[cipher]] [[algorithm]]. A good cipher algorithm, using different keys on the same plaintext, should generate a different ciphertext, irrespective of the key length.
Assume that there is a plaintext P, two different keys (of same length, assumed for simplicity) K1 and K2, and an algorithm A. Ciphertexts C1 and C2 with the two keys are generated as follows:▼
[[Cipher]]s (or algorithms) are used to [[encrypt]] the plaintext using keys. A good algorithm, using different keys on the same plaintext generates a different ciphertext, irrespective of the key length.
▲Assume that there is a plaintext P, two keys (of same length, assumed for simplicity) K1 and K2, and an algorithm A. Ciphertexts C1 and C2 with the two keys are generated as follows:
