wip on BR + added enc/dec for LWE

This commit is contained in:
Jean-Philippe Bossuat
2025-06-13 20:45:24 +02:00
parent e8cfb5e2ab
commit 829b8be610
43 changed files with 745 additions and 688 deletions

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@@ -0,0 +1,139 @@
use std::time::Instant;
use backend::{MatZnxDftOps, MatZnxDftScratch, Module, ScalarZnxDftOps, Scratch, VecZnxDftOps, VecZnxOps, ZnxView, ZnxViewMut, ZnxZero, FFT64};
use itertools::izip;
use crate::{
GGSWCiphertext, GLWECiphertext, GLWECiphertextToMut, GLWECiphertextToRef, GLWEPlaintext, Infos, LWECiphertext,
ScratchCore, blind_rotation::key::BlindRotationKeyCGGI, lwe::ciphertext::LWECiphertextToRef,
};
pub fn cggi_blind_rotate_scratch_space(
module: &Module<FFT64>,
basek: usize,
k_lut: usize,
k_brk: usize,
rows: usize,
rank: usize,
) -> usize {
let size = k_brk.div_ceil(basek);
GGSWCiphertext::<Vec<u8>, FFT64>::bytes_of(module, basek, k_brk, rows, 1, rank)
+ (module.mat_znx_dft_mul_x_pow_minus_one_scratch_space(size, rank + 1)
| GLWECiphertext::external_product_inplace_scratch_space(module, basek, k_lut, k_brk, 1, rank))
}
pub fn cggi_blind_rotate<DataRes, DataIn, DataLUT>(
module: &Module<FFT64>,
res: &mut GLWECiphertext<DataRes>,
lwe: &LWECiphertext<DataIn>,
lut: &GLWEPlaintext<DataLUT>,
brk: &BlindRotationKeyCGGI<FFT64>,
scratch: &mut Scratch,
) where
DataRes: AsRef<[u8]> + AsMut<[u8]>,
DataIn: AsRef<[u8]>,
DataLUT: AsRef<[u8]>,
{
println!("{}", lwe.n());
let mut lwe_2n: Vec<i64> = vec![0i64; lwe.n() + 1]; // TODO: from scratch space
let mut out_mut: GLWECiphertext<&mut [u8]> = res.to_mut();
let lwe_ref: LWECiphertext<&[u8]> = lwe.to_ref();
let lut_ref: GLWECiphertext<&[u8]> = lut.to_ref();
let cols = out_mut.rank()+1;
mod_switch_2n(module, &mut lwe_2n, &lwe_ref);
let a: &[i64] = &lwe_2n[1..];
let b: i64 = lwe_2n[0];
out_mut.data.zero();
// Initialize out to X^{b} * LUT(X)
module.vec_znx_rotate(b, &mut out_mut.data, 0, &lut_ref.data, 0);
let block_size: usize = brk.block_size();
// ACC + [sum DFT(X^ai -1) * (DFT(ACC) x BRKi)]
let (mut acc_dft, scratch1) = scratch.tmp_glwe_fourier(module, brk.basek(), out_mut.k(), out_mut.rank());
let (mut acc_add_dft, scratch2) = scratch1.tmp_glwe_fourier(module, brk.basek(), out_mut.k(), out_mut.rank());
let (mut vmp_res, scratch3) = scratch2.tmp_vec_znx_dft(module, acc_dft.rank()+1, acc_dft.size());
let (mut xai_minus_one, scratch4) = scratch3.tmp_scalar_znx(module, 1);
let (mut xai_minus_one_dft, scratch5) = scratch4.tmp_scalar_znx_dft(module, 1);
let start: Instant = Instant::now();
izip!(
a.chunks_exact(block_size),
brk.data.chunks_exact(block_size)
)
.for_each(|(ai, ski)| {
out_mut.dft(module, &mut acc_dft);
acc_add_dft.data.zero();
izip!(ai.iter(), ski.iter())
.enumerate()
.for_each(|(i, (aii, skii))| {
// vmp_res = DFT(acc) * BRK[i]
module.vmp_apply(&mut vmp_res, &acc_dft.data, &skii.data, scratch5);
// DFT(X^ai -1)
xai_minus_one.zero();
xai_minus_one.at_mut(0, 0)[0] = 1;
module.vec_znx_rotate_inplace(*aii, &mut xai_minus_one, 0);
xai_minus_one.at_mut(0, 0)[0] -= 1;
module.svp_prepare(&mut xai_minus_one_dft, 0, &xai_minus_one, 0);
// DFT(X^ai -1) * (DFT(acc) * BRK[i])
(0..cols).for_each(|i|{
module.svp_apply_inplace(&mut vmp_res, i, &xai_minus_one_dft, 0);
module.vec_znx_dft_add_inplace(&mut acc_add_dft.data, i, &vmp_res, i);
});
});
acc_add_dft.idft(module, &mut out_mut, scratch5);
});
let duration: std::time::Duration = start.elapsed();
println!("external products: {} us", duration.as_micros());
}
fn mod_switch_2n(module: &Module<FFT64>, res: &mut [i64], lwe: &LWECiphertext<&[u8]>) {
let basek: usize = lwe.basek();
let log2n: usize = module.log_n() + 1;
res.copy_from_slice(&lwe.data.at(0, 0));
if basek > log2n {
let diff: usize = basek - log2n;
res.iter_mut().for_each(|x| {
*x = div_signed_by_pow2(x, diff);
})
} else {
let rem: usize = basek - (log2n % basek);
let size: usize = log2n.div_ceil(basek);
(1..size).for_each(|i| {
if i == size - 1 && rem != basek {
let k_rem: usize = basek - rem;
izip!(lwe.data.at(0, i).iter(), res.iter_mut()).for_each(|(x, y)| {
*y = (*y << k_rem) + (x >> rem);
});
} else {
izip!(lwe.data.at(0, i).iter(), res.iter_mut()).for_each(|(x, y)| {
*y = (*y << basek) + x;
});
}
})
}
}
#[inline(always)]
fn div_signed_by_pow2(x: &i64, k: usize) -> i64 {
let bias: i64 = (1 << k) - 1;
(x + ((x >> 63) & bias)) >> k
}

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@@ -1,22 +1,22 @@
use backend::{Backend, FFT64, Module, ScalarZnx, ScalarZnxAlloc, ScalarZnxToRef, Scratch, ZnxView, ZnxViewMut};
use sampling::source::Source;
use crate::{Distribution, FourierGLWESecret, GGSWCiphertext, GLWEAutomorphismKey, LWESecret};
use crate::{Distribution, FourierGLWESecret, GGSWCiphertext, Infos, LWESecret};
pub struct BlindRotationKeyCGGI<B: Backend> {
pub(crate) data: Vec<GGSWCiphertext<Vec<u8>, B>>,
pub(crate) dist: Distribution,
}
pub struct BlindRotationKeyFHEW<B: Backend> {
pub(crate) data: Vec<GGSWCiphertext<Vec<u8>, B>>,
pub(crate) auto: Vec<GLWEAutomorphismKey<Vec<u8>, B>>,
}
// pub struct BlindRotationKeyFHEW<B: Backend> {
// pub(crate) data: Vec<GGSWCiphertext<Vec<u8>, B>>,
// pub(crate) auto: Vec<GLWEAutomorphismKey<Vec<u8>, B>>,
//}
impl BlindRotationKeyCGGI<FFT64> {
pub fn allocate(module: &Module<FFT64>, lwe_degree: usize, basek: usize, k: usize, rows: usize, rank: usize) -> Self {
let mut data: Vec<GGSWCiphertext<Vec<u8>, FFT64>> = Vec::with_capacity(lwe_degree);
(0..lwe_degree).for_each(|_| data.push(GGSWCiphertext::alloc(module, basek, k, rows, 1, rank)));
pub fn allocate(module: &Module<FFT64>, n_lwe: usize, basek: usize, k: usize, rows: usize, rank: usize) -> Self {
let mut data: Vec<GGSWCiphertext<Vec<u8>, FFT64>> = Vec::with_capacity(n_lwe);
(0..n_lwe).for_each(|_| data.push(GGSWCiphertext::alloc(module, basek, k, rows, 1, rank)));
Self {
data,
dist: Distribution::NONE,
@@ -61,4 +61,27 @@ impl BlindRotationKeyCGGI<FFT64> {
ggsw.encrypt_sk(module, &pt, sk_glwe, source_xa, source_xe, sigma, scratch);
})
}
pub(crate) fn block_size(&self) -> usize {
match self.dist {
Distribution::BinaryBlock(value) => value,
_ => 1,
}
}
pub(crate) fn rows(&self) -> usize {
self.data[0].rows()
}
pub(crate) fn k(&self) -> usize {
self.data[0].k()
}
pub(crate) fn rank(&self) -> usize {
self.data[0].rank()
}
pub(crate) fn basek(&self) -> usize {
self.data[0].basek()
}
}

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@@ -1,2 +1,6 @@
// pub mod cggi;
pub mod ccgi;
pub mod key;
#[cfg(test)]
pub mod test_fft64;

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@@ -0,0 +1,85 @@
use core::time;
use std::time::Instant;
use backend::{Encoding, Module, ScratchOwned, FFT64};
use sampling::source::Source;
use crate::{
blind_rotation::{ccgi::{cggi_blind_rotate, cggi_blind_rotate_scratch_space}, key::BlindRotationKeyCGGI}, lwe::LWEPlaintext, FourierGLWESecret, GLWECiphertext, GLWEPlaintext, GLWESecret, LWECiphertext, LWESecret
};
#[test]
fn blind_rotation() {
let module: Module<FFT64> = Module::<FFT64>::new(2048);
let basek: usize = 17;
let n_lwe: usize = 1071;
let k_lwe: usize = 22;
let k_brk: usize = 54;
let rows_brk: usize = 1;
let k_lut: usize = 44;
let rank: usize = 1;
let block_size: usize = 7;
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]);
let mut sk_glwe: GLWESecret<Vec<u8>> = GLWESecret::alloc(&module, rank);
sk_glwe.fill_ternary_prob(0.5, &mut source_xs);
let sk_glwe_dft: FourierGLWESecret<Vec<u8>, FFT64> = FourierGLWESecret::from(&module, &sk_glwe);
let mut sk_lwe: LWESecret<Vec<u8>> = LWESecret::alloc(n_lwe);
sk_lwe.fill_binary_block(block_size, &mut source_xs);
let mut scratch: ScratchOwned = ScratchOwned::new(BlindRotationKeyCGGI::generate_from_sk_scratch_space(
&module, basek, k_brk, rank,
) | cggi_blind_rotate_scratch_space(&module, basek, k_lut, k_brk, rows_brk, rank));
let start: Instant = Instant::now();
let mut brk: BlindRotationKeyCGGI<FFT64> = BlindRotationKeyCGGI::allocate(&module, n_lwe, basek, k_brk, rows_brk, rank);
brk.generate_from_sk(
&module,
&sk_glwe_dft,
&sk_lwe,
&mut source_xa,
&mut source_xe,
3.2,
scratch.borrow(),
);
let duration: std::time::Duration = start.elapsed();
println!("brk-gen: {} ms", duration.as_millis());
let mut lwe: LWECiphertext<Vec<u8>> = LWECiphertext::alloc(n_lwe, basek, k_lwe);
let mut pt_lwe: LWEPlaintext<Vec<u8>> = LWEPlaintext::alloc(basek, k_lwe);
pt_lwe.data.encode_coeff_i64(0, basek, 7, 0, 63, 7);
println!("{}", pt_lwe.data);
lwe.encrypt_sk(&pt_lwe, &sk_lwe, &mut source_xa, &mut source_xe, 3.2);
lwe.decrypt(&mut pt_lwe, &sk_lwe);
println!("{}", pt_lwe.data);
let lut: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(&module, basek, k_lut);
let mut res: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(&module, basek, k_lut, rank);
let start: Instant = Instant::now();
(0..32).for_each(|i|{
cggi_blind_rotate(&module, &mut res, &lwe, &lut, &brk, scratch.borrow());
});
let duration: std::time::Duration = start.elapsed();
println!("blind-rotate: {} ms", duration.as_millis());
let mut pt: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(&module, basek, k_lut);
res.decrypt(&module , &mut pt, &sk_glwe_dft, scratch.borrow());
println!("{}", pt.data);
}

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@@ -0,0 +1 @@
pub mod cggi;