create_multiparty_rotation_key

Engine.create_multiparty_rotation_key(rotation_keys, level)
Creates a common rotation key used for general rotations in multiparty computation. Requires an array of individual rotation keys as input. The common rotation key is internally composed of common fixed rotation keys of size \(2^n\). The value of n ranges from 0 to log_coeff_count - 1.
  • Input
    • rotation_keys: an array of RotationKeys
    • level: optional
      • Creates the key with a reduced size to contain only the specified multiplication levels.
  • Output
    • RotationKey

Warning

  • The matrix form does not support this operation.
from desilofhe import Engine

engine = Engine()
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
)

rotation_key1 = engine.create_individual_rotation_key(secret_key1, public_key)
rotation_key2 = engine.create_individual_rotation_key(secret_key2, public_key)

rotation_key = engine.create_multiparty_rotation_key(
    [rotation_key1, rotation_key2]
)

level_3_rotation_key = engine.create_multiparty_rotation_key(
    [rotation_key1, rotation_key2], level=3
)