1use backend::{
  2    Backend, FFT64, MatZnxDft, MatZnxDftAlloc, MatZnxDftOps, Module, ScalarZnx, Scratch, VecZnxAlloc, VecZnxDftAlloc, VecZnxOps,
  3    ZnxInfos, ZnxZero,
  4};
  5use sampling::source::Source;
  6
  7use crate::{GLWECiphertext, GLWECiphertextFourier, GLWEPlaintext, GetRow, Infos, SecretKeyFourier, SetRow, derive_size};
  8
  9pub struct GGLWECiphertext<C, B: Backend> {
 10    pub(crate) data: MatZnxDft<C, B>,
 11    pub(crate) basek: usize,
 12    pub(crate) k: usize,
 13}
 14
 15impl<B: Backend> GGLWECiphertext<Vec<u8>, B> {
 16    pub fn alloc(module: &Module<B>, basek: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
 17        Self {
 18            data: module.new_mat_znx_dft(rows, rank_in, rank_out + 1, derive_size(basek, k)),
 19            basek: basek,
 20            k,
 21        }
 22    }
 23
 24    pub fn bytes_of(module: &Module<FFT64>, basek: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> usize {
 25        module.bytes_of_mat_znx_dft(rows, rank_in, rank_out + 1, derive_size(basek, k))
 26    }
 27}
 28
 29impl<T, B: Backend> Infos for GGLWECiphertext<T, B> {
 30    type Inner = MatZnxDft<T, B>;
 31
 32    fn inner(&self) -> &Self::Inner {
 33        &self.data
 34    }
 35
 36    fn basek(&self) -> usize {
 37        self.basek
 38    }
 39
 40    fn k(&self) -> usize {
 41        self.k
 42    }
 43}
 44
 45impl<T, B: Backend> GGLWECiphertext<T, B> {
 46    pub fn rank(&self) -> usize {
 47        self.data.cols_out() - 1
 48    }
 49
 50    pub fn rank_in(&self) -> usize {
 51        self.data.cols_in()
 52    }
 53
 54    pub fn rank_out(&self) -> usize {
 55        self.data.cols_out() - 1
 56    }
 57}
 58
 59impl GGLWECiphertext<Vec<u8>, FFT64> {
 60    pub fn generate_from_sk_scratch_space(module: &Module<FFT64>, rank: usize, size: usize) -> usize {
 61        GLWECiphertext::encrypt_sk_scratch_space(module, size)
 62            + module.bytes_of_vec_znx(rank + 1, size)
 63            + module.bytes_of_vec_znx(1, size)
 64            + module.bytes_of_vec_znx_dft(rank + 1, size)
 65    }
 66
 67    pub fn generate_from_pk_scratch_space(_module: &Module<FFT64>, _rank: usize, _pk_size: usize) -> usize {
 68        unimplemented!()
 69    }
 70}
 71
 72impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> GGLWECiphertext<DataSelf, FFT64> {
 73    pub fn encrypt_sk<DataPt: AsRef<[u8]>, DataSk: AsRef<[u8]>>(
 74        &mut self,
 75        module: &Module<FFT64>,
 76        pt: &ScalarZnx<DataPt>,
 77        sk_dft: &SecretKeyFourier<DataSk, FFT64>,
 78        source_xa: &mut Source,
 79        source_xe: &mut Source,
 80        sigma: f64,
 81        scratch: &mut Scratch,
 82    ) {
 83        #[cfg(debug_assertions)]
 84        {
 85            assert_eq!(self.rank_in(), pt.cols());
 86            assert_eq!(self.rank_out(), sk_dft.rank());
 87            assert_eq!(self.n(), module.n());
 88            assert_eq!(sk_dft.n(), module.n());
 89            assert_eq!(pt.n(), module.n());
 90            assert!(
 91                scratch.available() >= GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank(), self.size()),
 92                "scratch.available: {} < GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank()={}, \
 93                 self.size()={}): {}",
 94                scratch.available(),
 95                self.rank(),
 96                self.size(),
 97                GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank(), self.size())
 98            )
 99        }
100
101        let rows: usize = self.rows();
102        let size: usize = self.size();
103        let basek: usize = self.basek();
104        let k: usize = self.k();
105
106        let cols_in: usize = self.rank_in();
107        let cols_out: usize = self.rank_out() + 1;
108
109        let (tmp_znx_pt, scrach_1) = scratch.tmp_vec_znx(module, 1, size);
110        let (tmp_znx_ct, scrach_2) = scrach_1.tmp_vec_znx(module, cols_out, size);
111        let (tmp_znx_dft_ct, scratch_3) = scrach_2.tmp_vec_znx_dft(module, cols_out, size);
112
113        let mut vec_znx_pt: GLWEPlaintext<&mut [u8]> = GLWEPlaintext {
114            data: tmp_znx_pt,
115            basek,
116            k,
117        };
118
119        let mut vec_znx_ct: GLWECiphertext<&mut [u8]> = GLWECiphertext {
120            data: tmp_znx_ct,
121            basek,
122            k,
123        };
124
125        let mut vec_znx_ct_dft: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier {
126            data: tmp_znx_dft_ct,
127            basek,
128            k,
129        };
130
131        // For each input column (i.e. rank) produces a GGLWE ciphertext of rank_out+1 columns
132        //
133        // Example for ksk rank 2 to rank 3:
134        //
135        // (-(a0*s0 + a1*s1 + a2*s2) + s0', a0, a1, a2)
136        // (-(b0*s0 + b1*s1 + b2*s2) + s0', b0, b1, b2)
137        //
138        // Example ksk rank 2 to rank 1
139        //
140        // (-(a*s) + s0, a)
141        // (-(b*s) + s1, b)
142        (0..cols_in).for_each(|col_i| {
143            (0..rows).for_each(|row_i| {
144                // Adds the scalar_znx_pt to the i-th limb of the vec_znx_pt
145                vec_znx_pt.data.zero(); // zeroes for next iteration
146                module.vec_znx_add_scalar_inplace(&mut vec_znx_pt.data, 0, row_i, pt, col_i); // Selects the i-th
147                module.vec_znx_normalize_inplace(basek, &mut vec_znx_pt.data, 0, scratch_3);
148
149                // rlwe encrypt of vec_znx_pt into vec_znx_ct
150                vec_znx_ct.encrypt_sk(
151                    module,
152                    &vec_znx_pt,
153                    sk_dft,
154                    source_xa,
155                    source_xe,
156                    sigma,
157                    scratch_3,
158                );
159
160                // Switch vec_znx_ct into DFT domain
161                vec_znx_ct.dft(module, &mut vec_znx_ct_dft);
162
163                // Stores vec_znx_dft_ct into thw i-th row of the MatZnxDft
164                module.vmp_prepare_row(&mut self.data, row_i, col_i, &vec_znx_ct_dft.data);
165            });
166        });
167    }
168}
169
170impl<C: AsRef<[u8]>> GetRow<FFT64> for GGLWECiphertext<C, FFT64> {
171    fn get_row<R: AsMut<[u8]> + AsRef<[u8]>>(
172        &self,
173        module: &Module<FFT64>,
174        row_i: usize,
175        col_j: usize,
176        res: &mut GLWECiphertextFourier<R, FFT64>,
177    ) {
178        module.vmp_extract_row(&mut res.data, &self.data, row_i, col_j);
179    }
180}
181
182impl<C: AsMut<[u8]> + AsRef<[u8]>> SetRow<FFT64> for GGLWECiphertext<C, FFT64> {
183    fn set_row<R: AsRef<[u8]>>(
184        &mut self,
185        module: &Module<FFT64>,
186        row_i: usize,
187        col_j: usize,
188        a: &GLWECiphertextFourier<R, FFT64>,
189    ) {
190        module.vmp_prepare_row(&mut self.data, row_i, col_j, &a.data);
191    }
192}