poulpy/core/src/automorphism.rs
core/src/automorphism.rsRaw
1use backend::{Backend, FFT64, MatZnxDft, MatZnxDftOps, Module, ScalarZnxOps, Scratch, VecZnx, VecZnxDftOps, VecZnxOps, ZnxZero};
2use sampling::source::Source;
3
4use crate::{
5 GGLWECiphertext, GGSWCiphertext, GLWECiphertext, GLWECiphertextFourier, GLWESecret, GLWESwitchingKey, GetRow, Infos,
6 ScratchCore, SetRow,
7};
8
9pub struct AutomorphismKey<Data, B: Backend> {
10 pub(crate) key: GLWESwitchingKey<Data, B>,
11 pub(crate) p: i64,
12}
13
14impl AutomorphismKey<Vec<u8>, FFT64> {
15 pub fn alloc(module: &Module<FFT64>, basek: usize, k: usize, rows: usize, digits: usize, rank: usize) -> Self {
16 AutomorphismKey {
17 key: GLWESwitchingKey::alloc(module, basek, k, rows, digits, rank, rank),
18 p: 0,
19 }
20 }
21
22 pub fn bytes_of(module: &Module<FFT64>, basek: usize, k: usize, rows: usize, digits: usize, rank: usize) -> usize {
23 GLWESwitchingKey::<Vec<u8>, FFT64>::bytes_of(module, basek, k, rows, digits,rank, rank)
24 }
25}
26
27impl<T, B: Backend> Infos for AutomorphismKey<T, B> {
28 type Inner = MatZnxDft<T, B>;
29
30 fn inner(&self) -> &Self::Inner {
31 &self.key.inner()
32 }
33
34 fn basek(&self) -> usize {
35 self.key.basek()
36 }
37
38 fn k(&self) -> usize {
39 self.key.k()
40 }
41}
42
43impl<T, B: Backend> AutomorphismKey<T, B> {
44 pub fn p(&self) -> i64 {
45 self.p
46 }
47
48 pub fn digits(&self) -> usize {
49 self.key.digits()
50 }
51
52 pub fn rank(&self) -> usize {
53 self.key.rank()
54 }
55
56 pub fn rank_in(&self) -> usize {
57 self.key.rank_in()
58 }
59
60 pub fn rank_out(&self) -> usize {
61 self.key.rank_out()
62 }
63}
64
65impl<C: AsRef<[u8]>> GetRow<FFT64> for AutomorphismKey<C, FFT64> {
66 fn get_row<R: AsMut<[u8]> + AsRef<[u8]>>(
67 &self,
68 module: &Module<FFT64>,
69 row_i: usize,
70 col_j: usize,
71 res: &mut GLWECiphertextFourier<R, FFT64>,
72 ) {
73 module.vmp_extract_row(&mut res.data, &self.key.0.data, row_i, col_j);
74 }
75}
76
77impl<C: AsMut<[u8]> + AsRef<[u8]>> SetRow<FFT64> for AutomorphismKey<C, FFT64> {
78 fn set_row<R: AsRef<[u8]>>(
79 &mut self,
80 module: &Module<FFT64>,
81 row_i: usize,
82 col_j: usize,
83 a: &GLWECiphertextFourier<R, FFT64>,
84 ) {
85 module.vmp_prepare_row(&mut self.key.0.data, row_i, col_j, &a.data);
86 }
87}
88
89impl AutomorphismKey<Vec<u8>, FFT64> {
90 pub fn generate_from_sk_scratch_space(module: &Module<FFT64>, basek: usize, k: usize, rank: usize) -> usize {
91 GGLWECiphertext::generate_from_sk_scratch_space(module, basek, k, rank) + GLWESecret::bytes_of(module, rank)
92 }
93
94 pub fn generate_from_pk_scratch_space(module: &Module<FFT64>, _basek: usize, _k: usize, _rank: usize) -> usize {
95 GGLWECiphertext::generate_from_pk_scratch_space(module, _basek, _k, _rank)
96 }
97
98 pub fn keyswitch_scratch_space(
99 module: &Module<FFT64>,
100 basek: usize,
101 out_k: usize,
102 in_k: usize,
103 ksk_k: usize,
104 rank: usize,
105 ) -> usize {
106 GLWESwitchingKey::keyswitch_scratch_space(module, basek, out_k, rank, in_k, rank, ksk_k)
107 }
108
109 pub fn keyswitch_inplace_scratch_space(
110 module: &Module<FFT64>,
111 basek: usize,
112 out_k: usize,
113 out_rank: usize,
114 ksk_k: usize,
115 ) -> usize {
116 GLWESwitchingKey::keyswitch_inplace_scratch_space(module, basek, out_k, out_rank, ksk_k)
117 }
118
119 pub fn automorphism_scratch_space(
120 module: &Module<FFT64>,
121 basek: usize,
122 out_k: usize,
123 in_k: usize,
124 atk_k: usize,
125 rank: usize,
126 ) -> usize {
127 let tmp_dft: usize = GLWECiphertextFourier::bytes_of(module, basek, in_k, rank);
128 let tmp_idft: usize = GLWECiphertextFourier::bytes_of(module, basek, out_k, rank);
129 let idft: usize = module.vec_znx_idft_tmp_bytes();
130 let keyswitch: usize = GLWECiphertext::keyswitch_inplace_scratch_space(module, basek, out_k, rank, atk_k);
131 tmp_dft + tmp_idft + idft + keyswitch
132 }
133
134 pub fn automorphism_inplace_scratch_space(
135 module: &Module<FFT64>,
136 basek: usize,
137 out_k: usize,
138 ksk_k: usize,
139 rank: usize,
140 ) -> usize {
141 AutomorphismKey::automorphism_scratch_space(module, basek, out_k, out_k, ksk_k, rank)
142 }
143
144 pub fn external_product_scratch_space(
145 module: &Module<FFT64>,
146 basek: usize,
147 out_k: usize,
148 in_k: usize,
149 ggsw_k: usize,
150 rank: usize,
151 ) -> usize {
152 GLWESwitchingKey::external_product_scratch_space(module, basek, out_k, in_k, ggsw_k, rank)
153 }
154
155 pub fn external_product_inplace_scratch_space(
156 module: &Module<FFT64>,
157 basek: usize,
158 out_k: usize,
159 ggsw_k: usize,
160 rank: usize,
161 ) -> usize {
162 GLWESwitchingKey::external_product_inplace_scratch_space(module, basek, out_k, ggsw_k, rank)
163 }
164}
165
166impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> AutomorphismKey<DataSelf, FFT64> {
167 pub fn generate_from_sk<DataSk: AsRef<[u8]>>(
168 &mut self,
169 module: &Module<FFT64>,
170 p: i64,
171 sk: &GLWESecret<DataSk, FFT64>,
172 source_xa: &mut Source,
173 source_xe: &mut Source,
174 sigma: f64,
175 scratch: &mut Scratch,
176 ) {
177 #[cfg(debug_assertions)]
178 {
179 assert_eq!(self.n(), module.n());
180 assert_eq!(sk.n(), module.n());
181 assert_eq!(self.rank_out(), self.rank_in());
182 assert_eq!(sk.rank(), self.rank());
183 assert!(
184 scratch.available()
185 >= AutomorphismKey::generate_from_sk_scratch_space(module, self.basek(), self.k(), self.rank()),
186 "scratch.available(): {} < AutomorphismKey::generate_from_sk_scratch_space(module, self.rank()={}, \
187 self.size()={}): {}",
188 scratch.available(),
189 self.rank(),
190 self.size(),
191 AutomorphismKey::generate_from_sk_scratch_space(module, self.basek(), self.k(), self.rank())
192 )
193 }
194
195 let (mut sk_out, scratch_1) = scratch.tmp_sk(module, sk.rank());
196 (0..self.rank()).for_each(|i| {
197 module.scalar_znx_automorphism(
198 module.galois_element_inv(p),
199 &mut sk_out.data,
200 i,
201 &sk.data,
202 i,
203 );
204 });
205
206 sk_out.prep_fourier(module);
207
208 self.key
209 .generate_from_sk(module, &sk, &sk_out, source_xa, source_xe, sigma, scratch_1);
210
211 self.p = p;
212 }
213}
214
215impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> AutomorphismKey<DataSelf, FFT64> {
216 pub fn automorphism<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
217 &mut self,
218 module: &Module<FFT64>,
219 lhs: &AutomorphismKey<DataLhs, FFT64>,
220 rhs: &AutomorphismKey<DataRhs, FFT64>,
221 scratch: &mut Scratch,
222 ) {
223 #[cfg(debug_assertions)]
224 {
225 assert_eq!(
226 self.rank_in(),
227 lhs.rank_in(),
228 "ksk_out input rank: {} != ksk_in input rank: {}",
229 self.rank_in(),
230 lhs.rank_in()
231 );
232 assert_eq!(
233 lhs.rank_out(),
234 rhs.rank_in(),
235 "ksk_in output rank: {} != ksk_apply input rank: {}",
236 self.rank_out(),
237 rhs.rank_in()
238 );
239 assert_eq!(
240 self.rank_out(),
241 rhs.rank_out(),
242 "ksk_out output rank: {} != ksk_apply output rank: {}",
243 self.rank_out(),
244 rhs.rank_out()
245 );
246 }
247
248 let cols_out: usize = rhs.rank_out() + 1;
249
250 let (mut tmp_dft, scratch1) = scratch.tmp_glwe_fourier(module, lhs.basek(), lhs.k(), lhs.rank());
251
252 (0..self.rank_in()).for_each(|col_i| {
253 (0..self.rows()).for_each(|row_j| {
254 // Extracts relevant row
255 lhs.get_row(module, row_j, col_i, &mut tmp_dft);
256
257 // Get a VecZnxBig from scratch space
258 let (mut tmp_idft_data, scratch2) = scratch1.tmp_vec_znx_big(module, cols_out, self.size());
259
260 // Switches input outside of DFT
261 (0..cols_out).for_each(|i| {
262 module.vec_znx_idft(&mut tmp_idft_data, i, &tmp_dft.data, i, scratch2);
263 });
264
265 // Consumes to small vec znx
266 let mut tmp_idft_small_data: VecZnx<&mut [u8]> = tmp_idft_data.to_vec_znx_small();
267
268 // Reverts the automorphis key from (-pi^{-1}_{k}(s)a + s, a) to (-sa + pi_{k}(s), a)
269 (0..cols_out).for_each(|i| {
270 module.vec_znx_automorphism_inplace(lhs.p(), &mut tmp_idft_small_data, i);
271 });
272
273 // Wraps into ciphertext
274 let mut tmp_idft: GLWECiphertext<&mut [u8]> = GLWECiphertext::<&mut [u8]> {
275 data: tmp_idft_small_data,
276 basek: self.basek(),
277 k: self.k(),
278 };
279
280 // Key-switch (-sa + pi_{k}(s), a) to (-pi^{-1}_{k'}(s)a + pi_{k}(s), a)
281 tmp_idft.keyswitch_inplace(module, &rhs.key, scratch2);
282
283 // Applies back the automorphism X^{k}: (-pi^{-1}_{k'}(s)a + pi_{k}(s), a) -> (-pi^{-1}_{k'+k}(s)a + s, a)
284 // and switches back to DFT domain
285 (0..self.rank_out() + 1).for_each(|i| {
286 module.vec_znx_automorphism_inplace(lhs.p(), &mut tmp_idft.data, i);
287 module.vec_znx_dft(&mut tmp_dft.data, i, &tmp_idft.data, i);
288 });
289
290 // Sets back the relevant row
291 self.set_row(module, row_j, col_i, &tmp_dft);
292 });
293 });
294
295 tmp_dft.data.zero();
296
297 (self.rows().min(lhs.rows())..self.rows()).for_each(|row_i| {
298 (0..self.rank_in()).for_each(|col_j| {
299 self.set_row(module, row_i, col_j, &tmp_dft);
300 });
301 });
302
303 self.p = (lhs.p * rhs.p) % (module.cyclotomic_order() as i64);
304 }
305
306 pub fn automorphism_inplace<DataRhs: AsRef<[u8]>>(
307 &mut self,
308 module: &Module<FFT64>,
309 rhs: &AutomorphismKey<DataRhs, FFT64>,
310 scratch: &mut Scratch,
311 ) {
312 unsafe {
313 let self_ptr: *mut AutomorphismKey<DataSelf, FFT64> = self as *mut AutomorphismKey<DataSelf, FFT64>;
314 self.automorphism(&module, &*self_ptr, rhs, scratch);
315 }
316 }
317
318 pub fn keyswitch<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
319 &mut self,
320 module: &Module<FFT64>,
321 lhs: &AutomorphismKey<DataLhs, FFT64>,
322 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
323 scratch: &mut Scratch,
324 ) {
325 self.key.keyswitch(module, &lhs.key, rhs, scratch);
326 }
327
328 pub fn keyswitch_inplace<DataRhs: AsRef<[u8]>>(
329 &mut self,
330 module: &Module<FFT64>,
331 rhs: &AutomorphismKey<DataRhs, FFT64>,
332 scratch: &mut Scratch,
333 ) {
334 self.key.keyswitch_inplace(module, &rhs.key, scratch);
335 }
336
337 pub fn external_product<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
338 &mut self,
339 module: &Module<FFT64>,
340 lhs: &AutomorphismKey<DataLhs, FFT64>,
341 rhs: &GGSWCiphertext<DataRhs, FFT64>,
342 scratch: &mut Scratch,
343 ) {
344 self.key.external_product(module, &lhs.key, rhs, scratch);
345 }
346
347 pub fn external_product_inplace<DataRhs: AsRef<[u8]>>(
348 &mut self,
349 module: &Module<FFT64>,
350 rhs: &GGSWCiphertext<DataRhs, FFT64>,
351 scratch: &mut Scratch,
352 ) {
353 self.key.external_product_inplace(module, rhs, scratch);
354 }
355}