import random from dataclasses import dataclass, field import typing import abc import numpy as np class Channel(abc.ABC): @abc.abstractmethod def send_classical(self, data: str, is_bob: bool = True): pass @abc.abstractmethod def send_bit(self, bit: bool, basis: bool): pass @abc.abstractmethod def recv_classical(self, n: int, is_bob: bool = True) -> str: pass @abc.abstractmethod def get_photon_results(self, basises: typing.Optional[typing.List[bool]]) -> typing.List[typing.Tuple[bool, bool]]: """ Returns tuple of clicks of 0 and 1 for each bit """ pass @dataclass class ChannelSym(Channel): # [[(value, basis)]] bob_photons: typing.List[typing.List[typing.Tuple[bool, bool]]] = field(default_factory=list) bob_classical_data_pool: str = '' alice_classical_data_pool: str = '' # probability for a photon to go to the wrong detector p_opt: float = 0.05 # dark count p_dc: float = 0.05 # the average number of emitted photons mu: float = 1 # eta - the probability for a detector to react to a photon detector_sensitivity: float = 0.8 transmittance: float = 0.8 eve: typing.Optional[typing.Any] = None def get_number_of_photos(self) -> int: return round(np.random.poisson(self.mu)) def send_classical(self, data: str, is_bob: bool = True): if is_bob: self.bob_classical_data_pool += data else: self.alice_classical_data_pool += data def send_bit(self, bit: bool, basis: bool): n_photons = self.get_number_of_photos() delta = [(bit, basis) for _i in range(n_photons)] if self.eve is not None: delta = self.eve.process_photons(delta) self.bob_photons.append(delta) def recv_classical(self, n: int, is_bob: bool = True) -> str: pool_name = ['alice_classical_data_pool', 'bob_classical_data_pool'][not is_bob] if n == -1: n = len(getattr(self, pool_name)) while len(getattr(self, pool_name)) < n: pass data = getattr(self, pool_name)[:n] setattr(self, pool_name, getattr(self, pool_name)[n:]) # print(f'{["Alice", "Bob"][is_bob]} received {n} characters') return data def get_photon_results(self, basises: typing.Optional[typing.List[bool]]) -> typing.List[typing.Tuple[bool, bool]]: res = list() while len(self.bob_photons) < len(basises): pass for photons, basis in zip(self.bob_photons, basises): clicks = [random.uniform(0, 1) <= self.p_dc, random.uniform(0, 1) <= self.p_dc] for ph_bit, ph_basis in photons: if random.uniform(0, 1) > self.transmittance: continue if random.uniform(0, 1) <= self.detector_sensitivity: # We detected everything correctly if ph_basis != basis: if random.uniform(0, 1) > 0.5: clicks[1] = True else: clicks[0] = True continue if random.uniform(0, 1) > self.p_opt: # Photon doesn't flip clicks[ph_bit] = True else: clicks[not ph_bit] = False res.append((clicks[0], clicks[1])) self.bob_photons = list() return res