1use std::collections::HashMap;
  2
  3use backend::{FFT64, FillUniform, Module, ScratchOwned, Stats, VecZnxOps, ZnxView, ZnxViewMut};
  4use sampling::source::Source;
  5
  6use crate::{AutomorphismKey, GLWECiphertext, GLWEPlaintext, GLWESecret, Infos, div_ceil, test_fft64::var_noise_gglwe_product};
  7
  8#[test]
  9fn trace_inplace() {
 10    let log_n: usize = 8;
 11    (1..4).for_each(|rank| {
 12        println!("test trace_inplace rank: {}", rank);
 13        test_trace_inplace(log_n, 8, 54, 3.2, rank);
 14    });
 15}
 16
 17fn test_trace_inplace(log_n: usize, basek: usize, k: usize, sigma: f64, rank: usize) {
 18    let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);
 19
 20    let k_autokey: usize = k + basek;
 21
 22    let digits: usize = 1;
 23    let rows: usize = div_ceil(k, digits * basek);
 24
 25    let mut ct: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(&module, basek, k, rank);
 26    let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(&module, basek, k);
 27    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(&module, basek, k);
 28
 29    let mut source_xs: Source = Source::new([0u8; 32]);
 30    let mut source_xe: Source = Source::new([0u8; 32]);
 31    let mut source_xa: Source = Source::new([0u8; 32]);
 32
 33    let mut scratch: ScratchOwned = ScratchOwned::new(
 34        GLWECiphertext::encrypt_sk_scratch_space(&module, basek, ct.k())
 35            | GLWECiphertext::decrypt_scratch_space(&module, basek, ct.k())
 36            | AutomorphismKey::generate_from_sk_scratch_space(&module, basek, k_autokey, rank)
 37            | GLWECiphertext::trace_inplace_scratch_space(&module, basek, ct.k(), k_autokey, digits, rank),
 38    );
 39
 40    let mut sk: GLWESecret<Vec<u8>, FFT64> = GLWESecret::alloc(&module, rank);
 41    sk.fill_ternary_prob(&&module, 0.5, &mut source_xs);
 42
 43    let mut data_want: Vec<i64> = vec![0i64; module.n()];
 44
 45    data_want
 46        .iter_mut()
 47        .for_each(|x| *x = source_xa.next_i64() & 0xFF);
 48
 49    pt_have
 50        .data
 51        .fill_uniform(basek, 0, pt_have.size(), &mut source_xa);
 52
 53    ct.encrypt_sk(
 54        &module,
 55        &pt_have,
 56        &sk,
 57        &mut source_xa,
 58        &mut source_xe,
 59        sigma,
 60        scratch.borrow(),
 61    );
 62
 63    let mut auto_keys: HashMap<i64, AutomorphismKey<Vec<u8>, FFT64>> = HashMap::new();
 64    let gal_els: Vec<i64> = GLWECiphertext::trace_galois_elements(&module);
 65    gal_els.iter().for_each(|gal_el| {
 66        let mut key: AutomorphismKey<Vec<u8>, FFT64> = AutomorphismKey::alloc(&module, basek, k_autokey, rows, digits, rank);
 67        key.generate_from_sk(
 68            &module,
 69            *gal_el,
 70            &sk,
 71            &mut source_xa,
 72            &mut source_xe,
 73            sigma,
 74            scratch.borrow(),
 75        );
 76        auto_keys.insert(*gal_el, key);
 77    });
 78
 79    ct.trace_inplace(&module, 0, 5, &auto_keys, scratch.borrow());
 80    ct.trace_inplace(&module, 5, log_n, &auto_keys, scratch.borrow());
 81
 82    (0..pt_want.size()).for_each(|i| pt_want.data.at_mut(0, i)[0] = pt_have.data.at(0, i)[0]);
 83
 84    ct.decrypt(&module, &mut pt_have, &sk, scratch.borrow());
 85
 86    module.vec_znx_sub_ab_inplace(&mut pt_want.data, 0, &pt_have.data, 0);
 87    module.vec_znx_normalize_inplace(basek, &mut pt_want.data, 0, scratch.borrow());
 88
 89    let noise_have = pt_want.data.std(0, basek).log2();
 90
 91    let mut noise_want: f64 = var_noise_gglwe_product(
 92        module.n() as f64,
 93        basek,
 94        0.5,
 95        0.5,
 96        1.0 / 12.0,
 97        sigma * sigma,
 98        0.0,
 99        rank as f64,
100        k,
101        k_autokey,
102    );
103    noise_want += sigma * sigma * (-2.0 * (k) as f64).exp2();
104    noise_want += module.n() as f64 * 1.0 / 12.0 * 0.5 * rank as f64 * (-2.0 * (k) as f64).exp2();
105    noise_want = noise_want.sqrt().log2();
106
107    assert!(
108        (noise_have - noise_want).abs() < 1.0,
109        "{} > {}",
110        noise_have,
111        noise_want
112    );
113}