poulpy/bin_fhe/blind_rotation/tests/generic_cggi.rs

use backend::hal::{
    api::{
        ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxAddNormal, VecZnxAddScalarInplace, VecZnxEncodeCoeffsi64, VecZnxFillUniform,
        VecZnxRotateInplace, VecZnxSub, VecZnxSwithcDegree, VmpPMatAlloc, VmpPMatPrepare, ZnxView,
    },
    layouts::{Backend, Module, ScratchOwned},
    oep::{
        ScratchAvailableImpl, ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl, TakeVecZnxBigImpl, TakeVecZnxDftImpl,
        TakeVecZnxDftSliceImpl, TakeVecZnxImpl, TakeVecZnxSliceImpl, VecZnxBigAllocBytesImpl, VecZnxDftAllocBytesImpl,
    },
};
use sampling::source::Source;

use crate::{
    BlindRotationKeyCGGI, BlindRotationKeyCGGIExec, BlindRotationKeyCGGIExecLayoutFamily, CCGIBlindRotationFamily, Infos,
    LookUpTable, cggi_blind_rotate, cggi_blind_rotate_scratch_space,
    layouts::{
        GLWECiphertext, GLWEPlaintext, GLWESecret, LWECiphertext, LWECiphertextToRef, LWEPlaintext, LWESecret,
        prepared::GLWESecretExec,
    },
    mod_switch_2n,
};

use crate::trait_families::{GLWEDecryptFamily, GLWESecretExecModuleFamily};

pub(crate) trait CGGITestModuleFamily<B: Backend> = CCGIBlindRotationFamily<B>
    + GLWESecretExecModuleFamily<B>
    + GLWEDecryptFamily<B>
    + BlindRotationKeyCGGIExecLayoutFamily<B>
    + VecZnxFillUniform
    + VecZnxAddNormal
    + VecZnxAddScalarInplace
    + VecZnxEncodeCoeffsi64
    + VecZnxRotateInplace
    + VecZnxSwithcDegree
    + VecZnxSub
    + VmpPMatAlloc<B>
    + VmpPMatPrepare<B>;
pub(crate) trait CGGITestScratchFamily<B: Backend> = VecZnxDftAllocBytesImpl<B>
    + VecZnxBigAllocBytesImpl<B>
    + ScratchOwnedAllocImpl<B>
    + ScratchOwnedBorrowImpl<B>
    + TakeVecZnxDftImpl<B>
    + TakeVecZnxBigImpl<B>
    + TakeVecZnxDftSliceImpl<B>
    + ScratchAvailableImpl<B>
    + TakeVecZnxImpl<B>
    + TakeVecZnxSliceImpl<B>;

pub(crate) fn blind_rotatio_test<B: Backend>(module: &Module<B>, n_lwe: usize, block_size: usize, extension_factor: usize)
where
    Module<B>: CGGITestModuleFamily<B>,
    B: CGGITestScratchFamily<B>,
{
    let n: usize = module.n();
    let basek: usize = 19;
    let k_lwe: usize = 24;
    let k_brk: usize = 3 * basek;
    let rows_brk: usize = 2; // Ensures first limb is noise-free.
    let k_lut: usize = 1 * basek;
    let k_res: usize = 2 * basek;
    let rank: usize = 1;

    let message_modulus: usize = 1 << 4;

    let mut source_xs: Source = Source::new([2u8; 32]);
    let mut source_xe: Source = Source::new([2u8; 32]);
    let mut source_xa: Source = Source::new([1u8; 32]);

    let mut sk_glwe: GLWESecret<Vec<u8>> = GLWESecret::alloc(n, rank);
    sk_glwe.fill_ternary_prob(0.5, &mut source_xs);
    let sk_glwe_dft: GLWESecretExec<Vec<u8>, B> = GLWESecretExec::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<B> = ScratchOwned::<B>::alloc(BlindRotationKeyCGGI::generate_from_sk_scratch_space(
        module, n, basek, k_brk, rank,
    ));

    let mut scratch_br: ScratchOwned<B> = ScratchOwned::<B>::alloc(cggi_blind_rotate_scratch_space(
        module,
        n,
        block_size,
        extension_factor,
        basek,
        k_res,
        k_brk,
        rows_brk,
        rank,
    ));

    let mut brk: BlindRotationKeyCGGI<Vec<u8>> = BlindRotationKeyCGGI::alloc(n, 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 mut lwe: LWECiphertext<Vec<u8>> = LWECiphertext::alloc(n_lwe, basek, k_lwe);

    let mut pt_lwe: LWEPlaintext<Vec<u8>> = LWEPlaintext::alloc(basek, k_lwe);

    let x: i64 = 2;
    let bits: usize = 8;

    module.encode_coeff_i64(basek, &mut pt_lwe.data, 0, bits, 0, x, bits);

    lwe.encrypt_sk(
        module,
        &pt_lwe,
        &sk_lwe,
        &mut source_xa,
        &mut source_xe,
        3.2,
    );

    let mut f: Vec<i64> = vec![0i64; message_modulus];
    f.iter_mut()
        .enumerate()
        .for_each(|(i, x)| *x = 2 * (i as i64) + 1);

    let mut lut: LookUpTable = LookUpTable::alloc(n, basek, k_lut, extension_factor);
    lut.set(module, &f, message_modulus);

    let mut res: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(n, basek, k_res, rank);

    let brk_exec: BlindRotationKeyCGGIExec<Vec<u8>, B> = BlindRotationKeyCGGIExec::from(module, &brk, scratch_br.borrow());

    cggi_blind_rotate(module, &mut res, &lwe, &lut, &brk_exec, scratch_br.borrow());

    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(n, basek, k_res);

    res.decrypt(module, &mut pt_have, &sk_glwe_dft, scratch.borrow());

    let mut lwe_2n: Vec<i64> = vec![0i64; lwe.n() + 1]; // TODO: from scratch space

    mod_switch_2n(
        2 * lut.domain_size(),
        &mut lwe_2n,
        &lwe.to_ref(),
        lut.rotation_direction(),
    );

    let pt_want: i64 = (lwe_2n[0]
        + lwe_2n[1..]
            .iter()
            .zip(sk_lwe.data.at(0, 0))
            .map(|(x, y)| x * y)
            .sum::<i64>())
        & (2 * lut.domain_size() - 1) as i64;

    lut.rotate(module, pt_want);

    // First limb should be exactly equal (test are parameterized such that the noise does not reach
    // the first limb)
    assert_eq!(pt_have.data.at(0, 0), lut.data[0].at(0, 0));
}