create_individual_fixed_roll_key

Engine.create_individual_fixed_roll_key(secret_key, public_key, shift, axis, *, level)

Create an individual fixed roll key, which is used to create a common fixed roll key for a specific shift amount of roll in multiparty computation. Requires a secret key and a public key.

• Input:
  • SecretKey
  • PublicKey
  • shift: int. It is generated by modulo operation within the range [0~slot count).
  • axis: None, optional. Must be None, since the matrix form does not support multiparty computation.
  • level: int, optional, keyword argument
    • 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
)

level_3_fixed_roll_key1 = engine.create_individual_fixed_roll_key(
    secret_key1, public_key, shift=1, level=3
)