poulpy/core/src/lwe/decryption.rs

use backend::{alloc_aligned, ZnxView, ZnxViewMut};

use crate::{lwe::{LWEPlaintext}, Infos, LWECiphertext, LWESecret, SetMetaData};

impl<DataSelf> LWECiphertext<DataSelf> where DataSelf: AsRef<[u8]>{
    pub fn decrypt<DataPt, DataSk>(&self, pt: &mut LWEPlaintext<DataPt>, sk: &LWESecret<DataSk>) where DataPt: AsRef<[u8]> + AsMut<[u8]>, DataSk: AsRef<[u8]>{
        #[cfg(debug_assertions)]{
            assert_eq!(self.n(), sk.n());
        }

        (0..pt.size().min(self.size())).for_each(|i|{
            pt.data.at_mut(0, i)[0] = self.data.at(0, i)[0] + self.data.at(0, i)[1..].iter().zip(sk.data.at(0, 0)).map(|(x, y)| x * y).sum::<i64>();
        });

        let mut tmp_bytes: Vec<u8> = alloc_aligned(size_of::<i64>());
        pt.data.normalize(self.basek(), 0, &mut tmp_bytes);

        pt.set_basek(self.basek());
        pt.set_k(self.k().min(pt.size() * self.basek()));
    }
}