Speck

class urca.cpu.blockciphers.speck.Speck(block_size: int = 32, key_size: int = 64, alpha: int = 7, beta: int = 2)

Bases: BlockCipher

The Speck block cipher.

Parameters:

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

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

• alpha (int, optional, default = 7) – the first rotation parameter

• beta (int, optional, default = 2) – the second rotation parameter

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

Dencrypt in-place.

Parameters:

• blocks (np.ndarray) – blocks

• keys (np.ndarray) – keys

• state_index (int) – index of the current state

• n_rounds (int) – number of decryption rounds

decrypt_function(blocks: ndarray, keys: ndarray) → None

Decrypt one round in-place.

Parameters:

• blocks (np.ndarray) – blocks

• keys (np.ndarray) – keys

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

Encrypt in-place.

Parameters:

• blocks (np.ndarray) – blocks

• keys (np.ndarray) – keys

• state_index (int) – index of the current state

• n_rounds (int) – number of encryption rounds

encrypt_function(blocks: ndarray, keys: ndarray) → None

Encrypt one round in-place.

Parameters:

• blocks (np.ndarray) – blocks

• keys (np.ndarray) – keys

revert_keys(keys: ndarray, round_number: int) → None

Revert the keys in-place.

Parameters:

• keys (np.ndarray) – keys

• round_number (int) – current round

update_keys(keys: ndarray, round_number: int) → None

Update the keys in-place.

Parameters:

• keys (np.ndarray) – keys

• round_number (int) – current round