fhelium.backend.ckks.rotation._galois

Map CKKS slot conventions to polynomial Galois elements.

rotation_galois_element

function View source

def rotation_galois_element(ring_dimension: int, rotation_step: int, generator: int=3) -> int: ...

Map signed rotation_step to odd polynomial galois_element.

The slot convention is torch.roll(slots, shifts=rotation_step). The result $g$ identifies automorphism ${\sigma }_g:X\mapsto X^g$ modulo $X^N+1$. The step and element are related but have distinct names.