create_multiparty_fixed_roll_key

Engine.create_multiparty_fixed_roll_key(individual_fixed_roll_keys, level)

Creates a common fixed roll key used for fixed roll in multiparty computation. Requires an array of individual fixed_roll keys as input.

• Input:
  • individual_fixed_roll_keys: list[FixedRollKey]
  • level: int, optional
    • Creates the key with a reduced size to contain only the specified multiplication levels.
• Output:
  • FixedRollKey

Warning

• The matrix form does not yet support this operation.

from desilofhe import Engine

engine = Engine(multiparty=True)
secret_key1 = engine.create_secret_key()
secret_key2 = engine.create_secret_key()
public_key_a = engine.create_public_key_a()
public_key_b1 = engine.create_public_key_b(secret_key1, public_key_a)
public_key_b2 = engine.create_public_key_b(secret_key2, public_key_a)

public_key = engine.create_multiparty_public_key(
    [public_key_b1, public_key_b2], public_key_a
)

fixed_roll_key1 = engine.create_individual_fixed_roll_key(
    secret_key1, public_key, shift=1
)
fixed_roll_key2 = engine.create_individual_fixed_roll_key(
    secret_key2, public_key, shift=1
)

fixed_roll_key = engine.create_multiparty_fixed_roll_key(
    [fixed_roll_key1, fixed_roll_key2]
)

level_3_fixed_roll_key = engine.create_multiparty_fixed_roll_key(
    [fixed_roll_key1, fixed_roll_key2], level=3
)