Added automorphism for glwe

This commit is contained in:
Jean-Philippe Bossuat
2025-05-16 14:15:41 +02:00
parent c86af112eb
commit 7434f289fe
7 changed files with 521 additions and 48 deletions

253
core/src/automorphism.rs Normal file
View File

@@ -0,0 +1,253 @@
use base2k::{
Backend, FFT64, MatZnxDft, MatZnxDftOps, MatZnxDftToMut, MatZnxDftToRef, Module, ScalarZnx, ScalarZnxDftOps, ScalarZnxOps,
ScalarZnxToRef, Scratch, VecZnxDft, VecZnxDftToMut, VecZnxDftToRef,
};
use sampling::source::Source;
use crate::{
elem::{GetRow, Infos, SetRow},
gglwe_ciphertext::GGLWECiphertext,
ggsw_ciphertext::GGSWCiphertext,
glwe_ciphertext_fourier::GLWECiphertextFourier,
keys::{SecretKey, SecretKeyFourier},
keyswitch_key::GLWESwitchingKey,
};
pub struct AutomorphismKey<Data, B: Backend> {
pub(crate) key: GLWESwitchingKey<Data, B>,
pub(crate) p: i64,
}
impl AutomorphismKey<Vec<u8>, FFT64> {
pub fn new(module: &Module<FFT64>, basek: usize, p: i64, k: usize, rows: usize, rank: usize) -> Self {
AutomorphismKey {
key: GLWESwitchingKey::new(module, basek, k, rows, rank, rank),
p: p,
}
}
}
impl<T, B: Backend> Infos for AutomorphismKey<T, B> {
type Inner = MatZnxDft<T, B>;
fn inner(&self) -> &Self::Inner {
&self.key.inner()
}
fn basek(&self) -> usize {
self.key.basek()
}
fn k(&self) -> usize {
self.key.k()
}
}
impl<T, B: Backend> AutomorphismKey<T, B> {
pub fn p(&self) -> i64 {
self.p
}
pub fn rank(&self) -> usize {
self.key.rank()
}
pub fn rank_in(&self) -> usize {
self.key.rank_in()
}
pub fn rank_out(&self) -> usize {
self.key.rank_out()
}
}
impl<DataSelf, B: Backend> MatZnxDftToMut<B> for AutomorphismKey<DataSelf, B>
where
MatZnxDft<DataSelf, B>: MatZnxDftToMut<B>,
{
fn to_mut(&mut self) -> MatZnxDft<&mut [u8], B> {
self.key.to_mut()
}
}
impl<DataSelf, B: Backend> MatZnxDftToRef<B> for AutomorphismKey<DataSelf, B>
where
MatZnxDft<DataSelf, B>: MatZnxDftToRef<B>,
{
fn to_ref(&self) -> MatZnxDft<&[u8], B> {
self.key.to_ref()
}
}
impl<C> GetRow<FFT64> for AutomorphismKey<C, FFT64>
where
MatZnxDft<C, FFT64>: MatZnxDftToRef<FFT64>,
{
fn get_row<R>(&self, module: &Module<FFT64>, row_i: usize, col_j: usize, res: &mut GLWECiphertextFourier<R, FFT64>)
where
VecZnxDft<R, FFT64>: VecZnxDftToMut<FFT64>,
{
module.vmp_extract_row(res, self, row_i, col_j);
}
}
impl<C> SetRow<FFT64> for AutomorphismKey<C, FFT64>
where
MatZnxDft<C, FFT64>: MatZnxDftToMut<FFT64>,
{
fn set_row<R>(&mut self, module: &Module<FFT64>, row_i: usize, col_j: usize, a: &GLWECiphertextFourier<R, FFT64>)
where
VecZnxDft<R, FFT64>: VecZnxDftToRef<FFT64>,
{
module.vmp_prepare_row(self, row_i, col_j, a);
}
}
impl AutomorphismKey<Vec<u8>, FFT64> {
pub fn encrypt_sk_scratch_space(module: &Module<FFT64>, rank: usize, size: usize) -> usize {
GGLWECiphertext::encrypt_sk_scratch_space(module, rank, size)
}
pub fn encrypt_pk_scratch_space(module: &Module<FFT64>, rank: usize, pk_size: usize) -> usize {
GGLWECiphertext::encrypt_pk_scratch_space(module, rank, pk_size)
}
pub fn keyswitch_scratch_space(
module: &Module<FFT64>,
out_size: usize,
in_size: usize,
ksk_size: usize,
rank: usize,
) -> usize {
GLWESwitchingKey::keyswitch_scratch_space(module, out_size, rank, in_size, rank, ksk_size)
}
pub fn keyswitch_inplace_scratch_space(module: &Module<FFT64>, out_size: usize, out_rank: usize, ksk_size: usize) -> usize {
GLWESwitchingKey::keyswitch_inplace_scratch_space(module, out_size, out_rank, ksk_size)
}
pub fn external_product_scratch_space(
module: &Module<FFT64>,
out_size: usize,
in_size: usize,
ggsw_size: usize,
rank: usize,
) -> usize {
GLWESwitchingKey::external_product_scratch_space(module, out_size, in_size, ggsw_size, rank)
}
pub fn external_product_inplace_scratch_space(
module: &Module<FFT64>,
out_size: usize,
ggsw_size: usize,
rank: usize,
) -> usize {
GLWESwitchingKey::external_product_inplace_scratch_space(module, out_size, ggsw_size, rank)
}
}
impl<DataSelf> AutomorphismKey<DataSelf, FFT64>
where
MatZnxDft<DataSelf, FFT64>: MatZnxDftToMut<FFT64> + MatZnxDftToRef<FFT64>,
{
pub fn encrypt_sk<DataSk>(
&mut self,
module: &Module<FFT64>,
p: i64,
sk: &SecretKey<DataSk>,
source_xa: &mut Source,
source_xe: &mut Source,
sigma: f64,
scratch: &mut Scratch,
) where
ScalarZnx<DataSk>: ScalarZnxToRef,
{
#[cfg(debug_assertions)]
{
assert_eq!(self.n(), module.n());
assert_eq!(sk.n(), module.n());
assert_eq!(self.rank_out(), self.rank_in());
assert_eq!(sk.rank(), self.rank());
}
let (sk_out_dft_data, scratch_1) = scratch.tmp_scalar_znx_dft(module, sk.rank());
let mut sk_out_dft: SecretKeyFourier<&mut [u8], FFT64> = SecretKeyFourier {
data: sk_out_dft_data,
dist: sk.dist,
};
{
(0..self.rank()).for_each(|i| {
let (mut sk_inv_auto, _) = scratch_1.tmp_scalar_znx(module, 1);
module.scalar_znx_automorphism(module.galois_element_inv(p), &mut sk_inv_auto, 0, sk, i);
module.svp_prepare(&mut sk_out_dft, i, &sk_inv_auto, 0);
});
}
self.key.encrypt_sk(
module,
&sk,
&sk_out_dft,
source_xa,
source_xe,
sigma,
scratch_1,
);
self.p = p;
}
}
impl<DataSelf> AutomorphismKey<DataSelf, FFT64>
where
MatZnxDft<DataSelf, FFT64>: MatZnxDftToMut<FFT64> + MatZnxDftToRef<FFT64>,
{
pub fn keyswitch<DataLhs, DataRhs>(
&mut self,
module: &Module<FFT64>,
lhs: &AutomorphismKey<DataLhs, FFT64>,
rhs: &GLWESwitchingKey<DataRhs, FFT64>,
scratch: &mut base2k::Scratch,
) where
MatZnxDft<DataLhs, FFT64>: MatZnxDftToRef<FFT64>,
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.key.keyswitch(module, &lhs.key, rhs, scratch);
}
pub fn keyswitch_inplace<DataRhs>(
&mut self,
module: &Module<FFT64>,
rhs: &AutomorphismKey<DataRhs, FFT64>,
scratch: &mut base2k::Scratch,
) where
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.key.keyswitch_inplace(module, &rhs.key, scratch);
}
pub fn external_product<DataLhs, DataRhs>(
&mut self,
module: &Module<FFT64>,
lhs: &AutomorphismKey<DataLhs, FFT64>,
rhs: &GGSWCiphertext<DataRhs, FFT64>,
scratch: &mut Scratch,
) where
MatZnxDft<DataLhs, FFT64>: MatZnxDftToRef<FFT64>,
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.key.external_product(module, &lhs.key, rhs, scratch);
}
pub fn external_product_inplace<DataRhs>(
&mut self,
module: &Module<FFT64>,
rhs: &GGSWCiphertext<DataRhs, FFT64>,
scratch: &mut Scratch,
) where
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.key.external_product_inplace(module, rhs, scratch);
}
}