Floor

In this notebook we will generate uniformly random shared secrets, then we will use the floor operator to return secrets with the fractional parts removed. We reveal the operands and the results to demonstrate correctness.

Note that we are initializing AdditiveProtocolSuite with a custom field order (251) and a FixedPoint encoding with 4 fractional bits so that the random secrets are small and easy to read in the output.

As with all operators in Cicada, floor applies element-wise to input arrays of any shape.

[1]:

import logging
import sys


import numpy

from cicada.additive import AdditiveProtocolSuite
from cicada.communicator import SocketCommunicator
from cicada.encoding import FixedPoint
from cicada.logging import Logger

logging.basicConfig(level=logging.INFO)

def main(communicator):
    log = Logger(logging.getLogger(), communicator)
    protocol = AdditiveProtocolSuite(communicator, order=251, encoding=FixedPoint(precision=4))
    generator = numpy.random.default_rng(seed=1234)

    for i in range(10):

        log.info("*" * 40, src=0)

        secret_share = protocol.field_uniform(generator=generator)
        secret = protocol.reveal(secret_share)
        log.info(f"Player {communicator.rank} secret: {secret}")

        floor_share = protocol.floor(secret_share)
        floor = protocol.reveal(floor_share)
        log.info(f"Player {communicator.rank} floor: {floor}")


SocketCommunicator.run(world_size=3, fn=main);

INFO:root:****************************************
INFO:root:Player 0 secret: 3.5
INFO:root:Player 1 secret: 3.5
INFO:root:Player 2 secret: 3.5
INFO:root:Player 0 floor: 3.0
INFO:root:Player 1 floor: 3.0
INFO:root:Player 2 floor: 3.0
INFO:root:****************************************
INFO:root:Player 0 secret: -1.5
INFO:root:Player 1 secret: -1.5
INFO:root:Player 2 secret: -1.5
INFO:root:Player 0 floor: -2.0
INFO:root:Player 1 floor: -2.0
INFO:root:Player 2 floor: -2.0
INFO:root:****************************************
INFO:root:Player 0 secret: -7.1875
INFO:root:Player 1 secret: -7.1875
INFO:root:Player 2 secret: -7.1875
INFO:root:Player 0 floor: 7.6875
INFO:root:Player 1 floor: 7.6875
INFO:root:Player 2 floor: 7.6875
INFO:root:****************************************
INFO:root:Player 0 secret: -0.75
INFO:root:Player 1 secret: -0.75
INFO:root:Player 2 secret: -0.75
INFO:root:Player 0 floor: -1.0
INFO:root:Player 1 floor: -1.0
INFO:root:Player 2 floor: -1.0
INFO:root:****************************************
INFO:root:Player 0 secret: 2.375
INFO:root:Player 1 secret: 2.375
INFO:root:Player 2 secret: 2.375
INFO:root:Player 0 floor: 2.0
INFO:root:Player 1 floor: 2.0
INFO:root:Player 2 floor: 2.0
INFO:root:****************************************
INFO:root:Player 0 secret: 7.5625
INFO:root:Player 1 secret: 7.5625
INFO:root:Player 2 secret: 7.5625
INFO:root:Player 0 floor: 7.0
INFO:root:Player 1 floor: 7.0
INFO:root:Player 2 floor: 7.0
INFO:root:****************************************
INFO:root:Player 0 secret: -4.75
INFO:root:Player 1 secret: -4.75
INFO:root:Player 2 secret: -4.75
INFO:root:Player 0 floor: -5.0
INFO:root:Player 1 floor: -5.0
INFO:root:Player 2 floor: -5.0
INFO:root:****************************************
INFO:root:Player 0 secret: -0.3125
INFO:root:Player 1 secret: -0.3125
INFO:root:Player 2 secret: -0.3125
INFO:root:Player 0 floor: -1.0
INFO:root:Player 1 floor: -1.0
INFO:root:Player 2 floor: -1.0
INFO:root:****************************************
INFO:root:Player 0 secret: -6.625
INFO:root:Player 1 secret: -6.625
INFO:root:Player 2 secret: -6.625
INFO:root:Player 0 floor: -7.0
INFO:root:Player 1 floor: -7.0
INFO:root:Player 2 floor: -7.0
INFO:root:****************************************
INFO:root:Player 0 secret: -2.5625
INFO:root:Player 1 secret: -2.5625
INFO:root:Player 2 secret: -2.5625
INFO:root:Player 0 floor: -3.0
INFO:root:Player 1 floor: -3.0
INFO:root:Player 2 floor: -3.0