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::{
  8    elem::{GetRow, Infos, SetRow},
  9    glwe_ciphertext::GLWECiphertext,
 10    glwe_ciphertext_fourier::GLWECiphertextFourier,
 11    glwe_plaintext::GLWEPlaintext,
 12    keys::SecretKeyFourier,
 13    utils::derive_size,
 14};
 15
 16pub struct GGLWECiphertext<C, B: Backend> {
 17    pub(crate) data: MatZnxDft<C, B>,
 18    pub(crate) basek: usize,
 19    pub(crate) k: usize,
 20}
 21
 22impl<B: Backend> GGLWECiphertext<Vec<u8>, B> {
 23    pub fn alloc(module: &Module<B>, basek: usize, k: usize, rows: usize, rank_in: usize, rank_out: usize) -> Self {
 24        Self {
 25            data: module.new_mat_znx_dft(rows, rank_in, rank_out + 1, derive_size(basek, k)),
 26            basek: basek,
 27            k,
 28        }
 29    }
 30}
 31
 32impl<T, B: Backend> Infos for GGLWECiphertext<T, B> {
 33    type Inner = MatZnxDft<T, B>;
 34
 35    fn inner(&self) -> &Self::Inner {
 36        &self.data
 37    }
 38
 39    fn basek(&self) -> usize {
 40        self.basek
 41    }
 42
 43    fn k(&self) -> usize {
 44        self.k
 45    }
 46}
 47
 48impl<T, B: Backend> GGLWECiphertext<T, B> {
 49    pub fn rank(&self) -> usize {
 50        self.data.cols_out() - 1
 51    }
 52
 53    pub fn rank_in(&self) -> usize {
 54        self.data.cols_in()
 55    }
 56
 57    pub fn rank_out(&self) -> usize {
 58        self.data.cols_out() - 1
 59    }
 60}
 61
 62impl GGLWECiphertext<Vec<u8>, FFT64> {
 63    pub fn generate_from_sk_scratch_space(module: &Module<FFT64>, rank: usize, size: usize) -> usize {
 64        GLWECiphertext::encrypt_sk_scratch_space(module, size)
 65            + module.bytes_of_vec_znx(rank + 1, size)
 66            + module.bytes_of_vec_znx(1, size)
 67            + module.bytes_of_vec_znx_dft(rank + 1, size)
 68    }
 69
 70    pub fn generate_from_pk_scratch_space(_module: &Module<FFT64>, _rank: usize, _pk_size: usize) -> usize {
 71        unimplemented!()
 72    }
 73}
 74
 75impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> GGLWECiphertext<DataSelf, FFT64> {
 76    pub fn encrypt_sk<DataPt: AsRef<[u8]>, DataSk: AsRef<[u8]>>(
 77        &mut self,
 78        module: &Module<FFT64>,
 79        pt: &ScalarZnx<DataPt>,
 80        sk_dft: &SecretKeyFourier<DataSk, FFT64>,
 81        source_xa: &mut Source,
 82        source_xe: &mut Source,
 83        sigma: f64,
 84        scratch: &mut Scratch,
 85    ) {
 86        #[cfg(debug_assertions)]
 87        {
 88            assert_eq!(self.rank_in(), pt.cols());
 89            assert_eq!(self.rank_out(), sk_dft.rank());
 90            assert_eq!(self.n(), module.n());
 91            assert_eq!(sk_dft.n(), module.n());
 92            assert_eq!(pt.n(), module.n());
 93            assert!(
 94                scratch.available() >= GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank(), self.size()),
 95                "scratch.available: {} < GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank()={}, \
 96                 self.size()={}): {}",
 97                scratch.available(),
 98                self.rank(),
 99                self.size(),
100                GGLWECiphertext::generate_from_sk_scratch_space(module, self.rank(), self.size())
101            )
102        }
103
104        let rows: usize = self.rows();
105        let size: usize = self.size();
106        let basek: usize = self.basek();
107        let k: usize = self.k();
108
109        let cols_in: usize = self.rank_in();
110        let cols_out: usize = self.rank_out() + 1;
111
112        let (tmp_znx_pt, scrach_1) = scratch.tmp_vec_znx(module, 1, size);
113        let (tmp_znx_ct, scrach_2) = scrach_1.tmp_vec_znx(module, cols_out, size);
114        let (tmp_znx_dft_ct, scratch_3) = scrach_2.tmp_vec_znx_dft(module, cols_out, size);
115
116        let mut vec_znx_pt: GLWEPlaintext<&mut [u8]> = GLWEPlaintext {
117            data: tmp_znx_pt,
118            basek,
119            k,
120        };
121
122        let mut vec_znx_ct: GLWECiphertext<&mut [u8]> = GLWECiphertext {
123            data: tmp_znx_ct,
124            basek,
125            k,
126        };
127
128        let mut vec_znx_ct_dft: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier {
129            data: tmp_znx_dft_ct,
130            basek,
131            k,
132        };
133
134        // For each input column (i.e. rank) produces a GGLWE ciphertext of rank_out+1 columns
135        //
136        // Example for ksk rank 2 to rank 3:
137        //
138        // (-(a0*s0 + a1*s1 + a2*s2) + s0', a0, a1, a2)
139        // (-(b0*s0 + b1*s1 + b2*s2) + s0', b0, b1, b2)
140        //
141        // Example ksk rank 2 to rank 1
142        //
143        // (-(a*s) + s0, a)
144        // (-(b*s) + s1, b)
145        (0..cols_in).for_each(|col_i| {
146            (0..rows).for_each(|row_i| {
147                // Adds the scalar_znx_pt to the i-th limb of the vec_znx_pt
148                vec_znx_pt.data.zero(); // zeroes for next iteration
149                module.vec_znx_add_scalar_inplace(&mut vec_znx_pt.data, 0, row_i, pt, col_i); // Selects the i-th
150                module.vec_znx_normalize_inplace(basek, &mut vec_znx_pt.data, 0, scratch_3);
151
152                // rlwe encrypt of vec_znx_pt into vec_znx_ct
153                vec_znx_ct.encrypt_sk(
154                    module,
155                    &vec_znx_pt,
156                    sk_dft,
157                    source_xa,
158                    source_xe,
159                    sigma,
160                    scratch_3,
161                );
162
163                // Switch vec_znx_ct into DFT domain
164                vec_znx_ct.dft(module, &mut vec_znx_ct_dft);
165
166                // Stores vec_znx_dft_ct into thw i-th row of the MatZnxDft
167                module.vmp_prepare_row(&mut self.data, row_i, col_i, &vec_znx_ct_dft.data);
168            });
169        });
170    }
171}
172
173impl<C: AsRef<[u8]>> GetRow<FFT64> for GGLWECiphertext<C, FFT64> {
174    fn get_row<R: AsMut<[u8]> + AsRef<[u8]>>(
175        &self,
176        module: &Module<FFT64>,
177        row_i: usize,
178        col_j: usize,
179        res: &mut GLWECiphertextFourier<R, FFT64>,
180    ) {
181        module.vmp_extract_row(&mut res.data, &self.data, row_i, col_j);
182    }
183}
184
185impl<C: AsMut<[u8]> + AsRef<[u8]>> SetRow<FFT64> for GGLWECiphertext<C, FFT64> {
186    fn set_row<R: AsRef<[u8]>>(
187        &mut self,
188        module: &Module<FFT64>,
189        row_i: usize,
190        col_j: usize,
191        a: &GLWECiphertextFourier<R, FFT64>,
192    ) {
193        module.vmp_prepare_row(&mut self.data, row_i, col_j, &a.data);
194    }
195}