roll

Ciphertext Roll

Engine.roll(ciphertext, roll_key, shift)
Rolls the input ciphertext to the right by the specified shift value. For example, rolling [1, 2, 3, 4] by 1 results in [4, 1, 2, 3]. In general, does not consume any level. A level is consumed only if the engine is not configured for bootstrapping and the ciphertext is at the maximum allowable level for a given parameter.
  • Input:
    • Ciphertext
    • RollKey
    • shift: int
  • Output:
    • Ciphertext
from desilofhe import Engine

engine = Engine()
secret_key = engine.create_secret_key()
public_key = engine.create_public_key(secret_key)
roll_key = engine.create_roll_key(secret_key)

message = [1, 2, 3]
ciphertext = engine.encrypt(message, public_key)
rolled_ciphertext = engine.roll(ciphertext, roll_key, shift=1)
Engine.roll(ciphertext, evaluation_key, shift)
Rolls the input ciphertext to the right by the specified shift value, using the roll key bundled in the evaluation key. For example, rolling [1, 2, 3, 4] by 1 results in [4, 1, 2, 3]. In general, does not consume any level. A level is consumed only if the engine is not configured for bootstrapping and the ciphertext is at the maximum allowable level for a given parameter.
  • Input:
    • Ciphertext
    • EvaluationKey
    • shift: int
  • Output:
    • Ciphertext

Warning

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

engine = Engine()
secret_key = engine.create_secret_key()
public_key = engine.create_public_key(secret_key)
evaluation_key = engine.create_evaluation_key(secret_key)

message = [1, 2, 3]
ciphertext = engine.encrypt(message, public_key)
rolled_ciphertext = engine.roll(ciphertext, evaluation_key, shift=1)

Plaintext Roll

Engine.roll(plaintext, shift)
Rolls the input plaintext to the right by the specified shift value. For example, rolling [1, 2, 3, 4] by 1 results in [4, 1, 2, 3].
  • Input:
    • Plaintext
    • shift: int
  • Output:
    • Plaintext
from desilofhe import Engine

engine = Engine()

message = [1, 2, 3]
plaintext = engine.encode(message)
rolled_plaintext = engine.roll(plaintext, shift=1)