Added automorphism + test on GGSW

This commit is contained in:
Jean-Philippe Bossuat
2025-05-20 21:38:38 +02:00
parent 640ff9ea61
commit fb35dfa0f7
2 changed files with 101 additions and 71 deletions

View File

@@ -1,6 +1,6 @@
use base2k::{
FFT64, Module, ScalarZnx, ScalarZnxAlloc, ScalarZnxDftOps, ScratchOwned, Stats, VecZnxBig, VecZnxBigAlloc, VecZnxBigOps,
VecZnxDft, VecZnxDftAlloc, VecZnxDftOps, VecZnxOps, VecZnxToMut, ZnxViewMut, ZnxZero,
FFT64, Module, ScalarZnx, ScalarZnxAlloc, ScalarZnxDftOps, ScalarZnxOps, ScratchOwned, Stats, VecZnxBig, VecZnxBigAlloc,
VecZnxBigOps, VecZnxDft, VecZnxDftAlloc, VecZnxDftOps, VecZnxOps, VecZnxToMut, ZnxViewMut, ZnxZero,
};
use sampling::source::Source;
@@ -292,14 +292,22 @@ pub(crate) fn noise_ggsw_keyswitch(
noise.log2().min(-1.0) // max noise is [-2^{-1}, 2^{-1}]
}
#[test]
fn automorphism() {
(1..4).for_each(|rank| {
println!("test automorphism rank: {}", rank);
test_automorphism(-5, 12, 15, 60, rank, 3.2);
});
}
fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize, sigma: f64) {
let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);
let rows: usize = (k + basek - 1) / basek;
let mut ct_in: GGSWCiphertext<Vec<u8>, FFT64> = GGSWCiphertext::new(&module, basek, k, rows, rank);
let mut ct_out: GGSWCiphertext<Vec<u8>, FFT64> = GGSWCiphertext::new(&module, basek, k, rows, rank);
let mut tsk: TensorKey<Vec<u8>, FFT64> = TensorKey::new(&module, basek, k, rows, rank);
let mut ksk: GLWESwitchingKey<Vec<u8>, FFT64> = GLWESwitchingKey::new(&module, basek, k, rows, rank, rank);
let mut tensor_key: TensorKey<Vec<u8>, FFT64> = TensorKey::new(&module, basek, k, rows, rank);
let mut auto_key: AutomorphismKey<Vec<u8>, FFT64> = AutomorphismKey::new(&module, basek, k, rows, rank);
let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k);
let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k);
let mut pt_scalar: ScalarZnx<Vec<u8>> = module.new_scalar_znx(1);
@@ -311,44 +319,38 @@ fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize,
let mut scratch: ScratchOwned = ScratchOwned::new(
GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct_in.size())
| GLWECiphertextFourier::decrypt_scratch_space(&module, ct_out.size())
| GLWESwitchingKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
| TensorKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
| GGSWCiphertext::keyswitch_scratch_space(
| AutomorphismKey::encrypt_sk_scratch_space(&module, rank, auto_key.size())
| TensorKey::encrypt_sk_scratch_space(&module, rank, tensor_key.size())
| GGSWCiphertext::automorphism_scratch_space(
&module,
ct_out.size(),
ct_in.size(),
ksk.size(),
tsk.size(),
auto_key.size(),
tensor_key.size(),
rank,
),
);
let var_xs: f64 = 0.5;
let mut sk_in: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
sk_in.fill_ternary_prob(var_xs, &mut source_xs);
let mut sk: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
sk.fill_ternary_prob(var_xs, &mut source_xs);
let mut sk_in_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
sk_in_dft.dft(&module, &sk_in);
let mut sk_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
sk_dft.dft(&module, &sk);
let mut sk_out: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
sk_out.fill_ternary_prob(var_xs, &mut source_xs);
let mut sk_out_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
sk_out_dft.dft(&module, &sk_out);
ksk.encrypt_sk(
auto_key.encrypt_sk(
&module,
&sk_in,
&sk_out_dft,
p,
&sk,
&mut source_xa,
&mut source_xe,
sigma,
scratch.borrow(),
);
tsk.encrypt_sk(
tensor_key.encrypt_sk(
&module,
&sk_out_dft,
&sk_dft,
&mut source_xa,
&mut source_xe,
sigma,
@@ -360,14 +362,16 @@ fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize,
ct_in.encrypt_sk(
&module,
&pt_scalar,
&sk_in_dft,
&sk_dft,
&mut source_xa,
&mut source_xe,
sigma,
scratch.borrow(),
);
ct_out.keyswitch(&module, &ct_in, &ksk, &tsk, scratch.borrow());
ct_out.automorphism(&module, &ct_in, &auto_key, &tensor_key, scratch.borrow());
module.scalar_znx_automorphism_inplace(p, &mut pt_scalar, 0);
let mut ct_glwe_fourier: GLWECiphertextFourier<Vec<u8>, FFT64> = GLWECiphertextFourier::new(&module, basek, k, rank);
let mut pt_dft: VecZnxDft<Vec<u8>, FFT64> = module.new_vec_znx_dft(1, ct_out.size());
@@ -380,14 +384,14 @@ fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize,
// mul with sk[col_j-1]
if col_j > 0 {
module.vec_znx_dft(&mut pt_dft, 0, &pt_want, 0);
module.svp_apply_inplace(&mut pt_dft, 0, &sk_out_dft, col_j - 1);
module.svp_apply_inplace(&mut pt_dft, 0, &sk_dft, col_j - 1);
module.vec_znx_idft_tmp_a(&mut pt_big, 0, &mut pt_dft, 0);
module.vec_znx_big_normalize(basek, &mut pt_want, 0, &pt_big, 0, scratch.borrow());
}
ct_out.get_row(&module, row_i, col_j, &mut ct_glwe_fourier);
ct_glwe_fourier.decrypt(&module, &mut pt_have, &sk_out_dft, scratch.borrow());
ct_glwe_fourier.decrypt(&module, &mut pt_have, &sk_dft, scratch.borrow());
module.vec_znx_sub_ab_inplace(&mut pt_have, 0, &pt_want, 0);