Simeck

class urca.cpu.blocks.simeck.Simeck(text_size: int = 32, key_size: int = 64, rot: tuple = (5, 1), z_sequence: int = 5557826286501673759)

Bases: Block

The Simeck block cipher.

Parameters:

• text_size (int, optional, default = 32) – the bit size of the block

• key_size (int, optional, default = 64) – the bit size of the key

• rot (tuple, optional, default = (5, 1)) – the rotation amounts in round schedule

• z_sequence (int, optional, default = constants.SIMECK_Z0) – the bit sequence for key schedule

decrypt(texts: ndarray, keys: ndarray, state_index: int, n_rounds: int) → None

Decrypt in-place.

Parameters:

• texts (np.ndarray) – ciphertexts

• keys (np.ndarray) – keys

• state_index (int) – index of the current state

• n_rounds (int) – number of decryption rounds

encrypt(texts: ndarray, keys: ndarray, state_index: int, n_rounds: int) → None

Encrypt using Simeck.

Parameters:

• texts (np.ndarray) – plaintexts

• keys (np.ndarray) – keys

• state_index (int) – index of the current state

• n_rounds (int) – number of encryption rounds

feistel(texts: ndarray, keys: ndarray) → None

Apply the Simeck Feistel function to texts.

Parameters:

• texts (np.ndarray) – plaintexts or texts

• keys (np.ndarray) – keys