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

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@@ -1,3 +1,4 @@
use crate::ffi::vec_znx;
use crate::znx_base::ZnxInfos;
use crate::{
Backend, DataView, DataViewMut, Module, VecZnx, VecZnxToMut, VecZnxToRef, ZnxSliceSize, ZnxView, ZnxViewMut, alloc_aligned,
@@ -122,6 +123,69 @@ impl<B: Backend> ScalarZnxAlloc for Module<B> {
}
}
pub trait ScalarZnxOps {
fn scalar_znx_automorphism<R, A>(&self, k: i64, res: &mut R, res_col: usize, a: &A, a_col: usize)
where
R: ScalarZnxToMut,
A: ScalarZnxToRef;
/// Applies the automorphism X^i -> X^ik on the selected column of `a`.
fn vec_znx_automorphism_inplace<A>(&self, k: i64, a: &mut A, a_col: usize)
where
A: ScalarZnxToMut;
}
impl<B: Backend> ScalarZnxOps for Module<B> {
fn scalar_znx_automorphism<R, A>(&self, k: i64, res: &mut R, res_col: usize, a: &A, a_col: usize)
where
R: ScalarZnxToMut,
A: ScalarZnxToRef,
{
let a: ScalarZnx<&[u8]> = a.to_ref();
let mut res: ScalarZnx<&mut [u8]> = res.to_mut();
#[cfg(debug_assertions)]
{
assert_eq!(a.n(), self.n());
assert_eq!(res.n(), self.n());
}
unsafe {
vec_znx::vec_znx_automorphism(
self.ptr,
k,
res.at_mut_ptr(res_col, 0),
res.size() as u64,
res.sl() as u64,
a.at_ptr(a_col, 0),
a.size() as u64,
a.sl() as u64,
)
}
}
fn vec_znx_automorphism_inplace<A>(&self, k: i64, a: &mut A, a_col: usize)
where
A: ScalarZnxToMut,
{
let mut a: ScalarZnx<&mut [u8]> = a.to_mut();
#[cfg(debug_assertions)]
{
assert_eq!(a.n(), self.n());
}
unsafe {
vec_znx::vec_znx_automorphism(
self.ptr,
k,
a.at_mut_ptr(a_col, 0),
a.size() as u64,
a.sl() as u64,
a.at_ptr(a_col, 0),
a.size() as u64,
a.sl() as u64,
)
}
}
}
impl<D> ScalarZnx<D> {
pub(crate) fn from_data(data: D, n: usize, cols: usize) -> Self {
Self { data, n, cols }

253
core/src/automorphism.rs Normal file
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@@ -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);
}
}

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@@ -21,10 +21,10 @@ pub struct GGLWECiphertext<C, B: Backend> {
}
impl<B: Backend> GGLWECiphertext<Vec<u8>, B> {
pub fn new(module: &Module<B>, base2k: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
pub fn new(module: &Module<B>, basek: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
Self {
data: module.new_mat_znx_dft(rows, rank_in, rank_out + 1, derive_size(base2k, k)),
basek: base2k,
data: module.new_mat_znx_dft(rows, rank_in, rank_out + 1, derive_size(basek, k)),
basek: basek,
k,
}
}
@@ -161,6 +161,7 @@ where
(0..cols_in).for_each(|col_i| {
(0..rows).for_each(|row_i| {
// Adds the scalar_znx_pt to the i-th limb of the vec_znx_pt
vec_znx_pt.data.zero(); // zeroes for next iteration
module.vec_znx_add_scalar_inplace(&mut vec_znx_pt, 0, row_i, pt, col_i); // Selects the i-th
module.vec_znx_normalize_inplace(basek, &mut vec_znx_pt, 0, scratch_3);
@@ -175,8 +176,6 @@ where
scratch_3,
);
vec_znx_pt.data.zero(); // zeroes for next iteration
// Switch vec_znx_ct into DFT domain
vec_znx_ct.dft(module, &mut vec_znx_ct_dft);

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@@ -8,6 +8,7 @@ use sampling::source::Source;
use crate::{
SIX_SIGMA,
automorphism::AutomorphismKey,
elem::Infos,
ggsw_ciphertext::GGSWCiphertext,
glwe_ciphertext_fourier::GLWECiphertextFourier,
@@ -137,21 +138,40 @@ impl GLWECiphertext<Vec<u8>> {
GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, out_size, out_rank, ksk_size)
}
pub fn automorphism_scratch_space(
module: &Module<FFT64>,
out_size: usize,
out_rank: usize,
in_size: usize,
autokey_size: usize,
) -> usize {
GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, in_size, out_rank, autokey_size)
}
pub fn automorphism_inplace_scratch_space(
module: &Module<FFT64>,
out_size: usize,
out_rank: usize,
autokey_size: usize,
) -> usize {
GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, out_size, out_rank, autokey_size)
}
pub fn external_product_scratch_space(
module: &Module<FFT64>,
out_size: usize,
out_rank: usize,
in_size: usize,
ggsw_size: usize,
rank: usize,
) -> usize {
let res_dft: usize = module.bytes_of_vec_znx_dft(rank + 1, ggsw_size);
let vmp: usize = module.bytes_of_vec_znx_dft(rank + 1, in_size)
let res_dft: usize = module.bytes_of_vec_znx_dft(out_rank + 1, ggsw_size);
let vmp: usize = module.bytes_of_vec_znx_dft(out_rank + 1, in_size)
+ module.vmp_apply_tmp_bytes(
out_size,
in_size,
in_size, // rows
rank + 1, // cols in
rank + 1, // cols out
out_rank + 1, // cols in
out_rank + 1, // cols out
ggsw_size,
);
let normalize: usize = module.vec_znx_big_normalize_tmp_bytes();
@@ -159,8 +179,13 @@ impl GLWECiphertext<Vec<u8>> {
res_dft + (vmp | normalize)
}
pub fn external_product_inplace_scratch_space(module: &Module<FFT64>, res_size: usize, rhs: usize, rank: usize) -> usize {
GLWECiphertext::external_product_scratch_space(module, res_size, res_size, rhs, rank)
pub fn external_product_inplace_scratch_space(
module: &Module<FFT64>,
out_size: usize,
out_rank: usize,
ggsw_size: usize,
) -> usize {
GLWECiphertext::external_product_scratch_space(module, out_size, out_rank, out_size, ggsw_size)
}
}
@@ -244,6 +269,36 @@ where
self.encrypt_pk_private(module, None, pk, source_xu, source_xe, sigma, scratch);
}
pub fn automorphism<DataLhs, DataRhs>(
&mut self,
module: &Module<FFT64>,
lhs: &GLWECiphertext<DataLhs>,
rhs: &AutomorphismKey<DataRhs, FFT64>,
scratch: &mut Scratch,
) where
VecZnx<DataLhs>: VecZnxToRef,
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.keyswitch(module, lhs, &rhs.key, scratch);
//(0..self.rank() + 1).for_each(|i| {
// module.vec_znx_automorphism_inplace(rhs.p(), self, i);
//})
}
pub fn automorphism_inplace<DataRhs>(
&mut self,
module: &Module<FFT64>,
rhs: &AutomorphismKey<DataRhs, FFT64>,
scratch: &mut Scratch,
) where
MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
{
self.keyswitch_inplace(module, &rhs.key, scratch);
(0..self.rank() + 1).for_each(|i| {
module.vec_znx_automorphism_inplace(rhs.p(), self, i);
})
}
pub fn keyswitch<DataLhs, DataRhs>(
&mut self,
module: &Module<FFT64>,

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@@ -15,9 +15,9 @@ use crate::{
pub struct GLWESwitchingKey<Data, B: Backend>(pub(crate) GGLWECiphertext<Data, B>);
impl GLWESwitchingKey<Vec<u8>, FFT64> {
pub fn new(module: &Module<FFT64>, base2k: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
pub fn new(module: &Module<FFT64>, basek: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
GLWESwitchingKey(GGLWECiphertext::new(
module, base2k, k, rows, rank_in, rank_out,
module, basek, k, rows, rank_in, rank_out,
))
}
}
@@ -26,7 +26,7 @@ impl<T, B: Backend> Infos for GLWESwitchingKey<T, B> {
type Inner = MatZnxDft<T, B>;
fn inner(&self) -> &Self::Inner {
&self.0.inner()
self.0.inner()
}
fn basek(&self) -> usize {
@@ -102,38 +102,7 @@ impl GLWESwitchingKey<Vec<u8>, FFT64> {
pub fn encrypt_pk_scratch_space(module: &Module<FFT64>, rank: usize, pk_size: usize) -> usize {
GGLWECiphertext::encrypt_pk_scratch_space(module, rank, pk_size)
}
}
impl<DataSelf> GLWESwitchingKey<DataSelf, FFT64>
where
MatZnxDft<DataSelf, FFT64>: MatZnxDftToMut<FFT64> + MatZnxDftToRef<FFT64>,
{
pub fn encrypt_sk<DataSkIn, DataSkOut>(
&mut self,
module: &Module<FFT64>,
sk_in: &SecretKey<DataSkIn>,
sk_out_dft: &SecretKeyFourier<DataSkOut, FFT64>,
source_xa: &mut Source,
source_xe: &mut Source,
sigma: f64,
scratch: &mut Scratch,
) where
ScalarZnx<DataSkIn>: ScalarZnxToRef,
ScalarZnxDft<DataSkOut, FFT64>: ScalarZnxDftToRef<FFT64>,
{
self.0.encrypt_sk(
module,
&sk_in.data,
sk_out_dft,
source_xa,
source_xe,
sigma,
scratch,
);
}
}
impl GLWESwitchingKey<Vec<u8>, FFT64> {
pub fn keyswitch_scratch_space(
module: &Module<FFT64>,
out_size: usize,
@@ -178,11 +147,34 @@ impl GLWESwitchingKey<Vec<u8>, FFT64> {
tmp + ggsw
}
}
impl<DataSelf> GLWESwitchingKey<DataSelf, FFT64>
where
MatZnxDft<DataSelf, FFT64>: MatZnxDftToMut<FFT64> + MatZnxDftToRef<FFT64>,
{
pub fn encrypt_sk<DataSkIn, DataSkOut>(
&mut self,
module: &Module<FFT64>,
sk_in: &SecretKey<DataSkIn>,
sk_out_dft: &SecretKeyFourier<DataSkOut, FFT64>,
source_xa: &mut Source,
source_xe: &mut Source,
sigma: f64,
scratch: &mut Scratch,
) where
ScalarZnx<DataSkIn>: ScalarZnxToRef,
ScalarZnxDft<DataSkOut, FFT64>: ScalarZnxDftToRef<FFT64>,
{
self.0.encrypt_sk(
module,
&sk_in.data,
sk_out_dft,
source_xa,
source_xe,
sigma,
scratch,
);
}
pub fn keyswitch<DataLhs, DataRhs>(
&mut self,
module: &Module<FFT64>,

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@@ -1,3 +1,4 @@
pub mod automorphism;
pub mod elem;
pub mod gglwe_ciphertext;
pub mod ggsw_ciphertext;

View File

@@ -6,6 +6,7 @@ use itertools::izip;
use sampling::source::Source;
use crate::{
automorphism::AutomorphismKey,
elem::Infos,
ggsw_ciphertext::GGSWCiphertext,
glwe_ciphertext::GLWECiphertext,
@@ -415,6 +416,114 @@ fn test_keyswitch_inplace(log_n: usize, basek: usize, k_ksk: usize, k_ct: usize,
);
}
#[test]
fn automorphism() {
(1..4).for_each(|rank| {
println!("test automorphism rank: {}", rank);
test_automorphism(12, 12, 1, 60, 45, 60, rank, 3.2);
});
}
fn test_automorphism(
log_n: usize,
basek: usize,
p: i64,
k_autokey: usize,
k_ct_in: usize,
k_ct_out: usize,
rank: usize,
sigma: f64,
) {
let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);
let rows: usize = (k_ct_in + basek - 1) / basek;
let mut autokey: AutomorphismKey<Vec<u8>, FFT64> = AutomorphismKey::new(&module, basek, p, k_autokey, rows, rank);
let mut ct_in: GLWECiphertext<Vec<u8>> = GLWECiphertext::new(&module, basek, k_ct_in, rank);
let mut ct_out: GLWECiphertext<Vec<u8>> = GLWECiphertext::new(&module, basek, k_ct_out, rank);
let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k_ct_in);
let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k_ct_out);
let mut source_xs: Source = Source::new([0u8; 32]);
let mut source_xe: Source = Source::new([0u8; 32]);
let mut source_xa: Source = Source::new([0u8; 32]);
// Random input plaintext
// pt_want
// .data
// .fill_uniform(basek, 0, pt_want.size(), &mut source_xa);
pt_want
.to_mut()
.at_mut(0, 1)
.iter_mut()
.enumerate()
.for_each(|(i, x)| {
*x = i as i64;
});
let mut scratch: ScratchOwned = ScratchOwned::new(
GLWESwitchingKey::encrypt_sk_scratch_space(&module, rank, autokey.size())
| GLWECiphertext::decrypt_scratch_space(&module, ct_out.size())
| GLWECiphertext::encrypt_sk_scratch_space(&module, ct_in.size())
| GLWECiphertext::automorphism_scratch_space(&module, ct_out.size(), rank, ct_in.size(), autokey.size()),
);
let mut sk: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
sk.fill_ternary_prob(0.5, &mut source_xs);
let mut sk_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
sk_dft.dft(&module, &sk);
autokey.encrypt_sk(
&module,
p,
&sk,
&mut source_xa,
&mut source_xe,
sigma,
scratch.borrow(),
);
ct_in.encrypt_sk(
&module,
&pt_want,
&sk_dft,
&mut source_xa,
&mut source_xe,
sigma,
scratch.borrow(),
);
ct_out.automorphism(&module, &ct_in, &autokey, scratch.borrow());
ct_out.decrypt(&module, &mut pt_have, &sk_dft, scratch.borrow());
module.vec_znx_automorphism_inplace(p, &mut pt_want, 0);
module.vec_znx_sub_ab_inplace(&mut pt_have, 0, &pt_want, 0);
let noise_have: f64 = pt_have.data.std(0, basek).log2();
let noise_want: f64 = noise_gglwe_product(
module.n() as f64,
basek,
0.5,
0.5,
0f64,
sigma * sigma,
0f64,
rank as f64,
k_ct_in,
k_autokey,
);
assert!(
(noise_have - noise_want).abs() <= 0.1,
"{} {}",
noise_have,
noise_want
);
}
fn test_external_product(log_n: usize, basek: usize, k_ggsw: usize, k_ct_in: usize, k_ct_out: usize, rank: usize, sigma: f64) {
let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);