def _one_biconf_iteration(self):
self.stats.biconf_iterations += 1
cascade = self._algorithm.biconf_cascade
# Randomly select half of the bits in the key. This is exactly the same as doing a new
# random shuffle of the key and selecting the first half of newly shuffled key.
key_size = self._reconciled_key.get_size()
shuffle = Shuffle(key_size, Shuffle.SHUFFLE_RANDOM)
mid_index = key_size // 2
chosen_block = Block(self._reconciled_key, shuffle, 0, mid_index, None)
if cascade:
self._register_block_key_indexes(chosen_block)
# Ask Alice what the correct parity of the chosen block is.
self._schedule_ask_correct_parity(chosen_block, False)
# If the algorithm wants it, also ask Alice what the correct parity of the complementary
# block is.
if self._algorithm.biconf_correct_complement:
complement_block = Block(self._reconciled_key, shuffle, mid_index,
key_size, None)
if cascade:
self._register_block_key_indexes(complement_block)
self._schedule_ask_correct_parity(complement_block, False)
# Service all pending correction attempts (potentially including Cascaded ones) and ask
# parity messages.
errors_corrected = self._service_all_pending_work(cascade)
return errors_corrected
def test_create_block():
# Block covers entire shuffle.
Key.set_random_seed(2221)
Shuffle.set_random_seed(2222)
key = Key.create_random_key(8)
assert key.__repr__() == "Key: 10111010"
shuffle = Shuffle(key.get_size(), Shuffle.SHUFFLE_RANDOM)
assert shuffle.__repr__(
) == "Shuffle: 0->0 1->1 2->6 3->4 4->3 5->2 6->5 7->7"
block = Block(key, shuffle, 3, 6, None)
assert block.__repr__() == "Block: 3->4=1 4->3=1 5->2=1"
block = Block(key, shuffle, 0, 8, None)
assert block.__repr__(
) == "Block: 0->0=1 1->1=0 2->6=1 3->4=1 4->3=1 5->2=1 6->5=0 7->7=0"
# Block covers part of the shuffle.
block = Block(key, shuffle, 1, 3, None)
assert block.__repr__() == "Block: 1->1=0 2->6=1"
# Single bit block.
block = Block(key, shuffle, 2, 3, None)
assert block.__repr__() == "Block: 2->6=1"