poulpy/core/src/automorphism.rs
core/src/automorphism.rsRaw
1use backend::{
2 Backend, FFT64, MatZnxDft, MatZnxDftOps, Module, ScalarZnxDftAlloc, ScalarZnxDftOps, ScalarZnxOps, Scratch, VecZnx,
3 VecZnxBigAlloc, VecZnxDftAlloc, VecZnxDftOps, VecZnxOps, ZnxZero,
4};
5use sampling::source::Source;
6
7use crate::{
8 elem::{GetRow, Infos, SetRow},
9 gglwe_ciphertext::GGLWECiphertext,
10 ggsw_ciphertext::GGSWCiphertext,
11 glwe_ciphertext::GLWECiphertext,
12 glwe_ciphertext_fourier::GLWECiphertextFourier,
13 keys::{SecretKey, SecretKeyFourier},
14 keyswitch_key::GLWESwitchingKey,
15};
16
17pub struct AutomorphismKey<Data, B: Backend> {
18 pub(crate) key: GLWESwitchingKey<Data, B>,
19 pub(crate) p: i64,
20}
21
22impl AutomorphismKey<Vec<u8>, FFT64> {
23 pub fn alloc(module: &Module<FFT64>, basek: usize, k: usize, rows: usize, rank: usize) -> Self {
24 AutomorphismKey {
25 key: GLWESwitchingKey::alloc(module, basek, k, rows, rank, rank),
26 p: 0,
27 }
28 }
29}
30
31impl<T, B: Backend> Infos for AutomorphismKey<T, B> {
32 type Inner = MatZnxDft<T, B>;
33
34 fn inner(&self) -> &Self::Inner {
35 &self.key.inner()
36 }
37
38 fn basek(&self) -> usize {
39 self.key.basek()
40 }
41
42 fn k(&self) -> usize {
43 self.key.k()
44 }
45}
46
47impl<T, B: Backend> AutomorphismKey<T, B> {
48 pub fn p(&self) -> i64 {
49 self.p
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>, rank: usize, size: usize) -> usize {
91 GGLWECiphertext::generate_from_sk_scratch_space(module, rank, size) + module.bytes_of_scalar_znx_dft(rank)
92 }
93
94 pub fn generate_from_pk_scratch_space(module: &Module<FFT64>, rank: usize, pk_size: usize) -> usize {
95 GGLWECiphertext::generate_from_pk_scratch_space(module, rank, pk_size)
96 }
97
98 pub fn keyswitch_scratch_space(
99 module: &Module<FFT64>,
100 out_size: usize,
101 in_size: usize,
102 ksk_size: usize,
103 rank: usize,
104 ) -> usize {
105 GLWESwitchingKey::keyswitch_scratch_space(module, out_size, rank, in_size, rank, ksk_size)
106 }
107
108 pub fn keyswitch_inplace_scratch_space(module: &Module<FFT64>, out_size: usize, out_rank: usize, ksk_size: usize) -> usize {
109 GLWESwitchingKey::keyswitch_inplace_scratch_space(module, out_size, out_rank, ksk_size)
110 }
111
112 pub fn automorphism_scratch_space(
113 module: &Module<FFT64>,
114 out_size: usize,
115 in_size: usize,
116 ksk_size: usize,
117 rank: usize,
118 ) -> usize {
119 let tmp_dft: usize = module.bytes_of_vec_znx_dft(rank + 1, in_size);
120 let tmp_idft: usize = module.bytes_of_vec_znx_big(rank + 1, out_size);
121 let idft: usize = module.vec_znx_idft_tmp_bytes();
122 let keyswitch: usize = GLWECiphertext::keyswitch_inplace_scratch_space(module, out_size, rank, ksk_size);
123 tmp_dft + tmp_idft + idft + keyswitch
124 }
125
126 pub fn automorphism_inplace_scratch_space(module: &Module<FFT64>, out_size: usize, ksk_size: usize, rank: usize) -> usize {
127 AutomorphismKey::automorphism_scratch_space(module, out_size, out_size, ksk_size, rank)
128 }
129
130 pub fn external_product_scratch_space(
131 module: &Module<FFT64>,
132 out_size: usize,
133 in_size: usize,
134 ggsw_size: usize,
135 rank: usize,
136 ) -> usize {
137 GLWESwitchingKey::external_product_scratch_space(module, out_size, in_size, ggsw_size, rank)
138 }
139
140 pub fn external_product_inplace_scratch_space(
141 module: &Module<FFT64>,
142 out_size: usize,
143 ggsw_size: usize,
144 rank: usize,
145 ) -> usize {
146 GLWESwitchingKey::external_product_inplace_scratch_space(module, out_size, ggsw_size, rank)
147 }
148}
149
150impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> AutomorphismKey<DataSelf, FFT64> {
151 pub fn generate_from_sk<DataSk: AsRef<[u8]>>(
152 &mut self,
153 module: &Module<FFT64>,
154 p: i64,
155 sk: &SecretKey<DataSk>,
156 source_xa: &mut Source,
157 source_xe: &mut Source,
158 sigma: f64,
159 scratch: &mut Scratch,
160 ) {
161 #[cfg(debug_assertions)]
162 {
163 assert_eq!(self.n(), module.n());
164 assert_eq!(sk.n(), module.n());
165 assert_eq!(self.rank_out(), self.rank_in());
166 assert_eq!(sk.rank(), self.rank());
167 assert!(
168 scratch.available() >= AutomorphismKey::generate_from_sk_scratch_space(module, self.rank(), self.size()),
169 "scratch.available(): {} < AutomorphismKey::generate_from_sk_scratch_space(module, self.rank()={}, \
170 self.size()={}): {}",
171 scratch.available(),
172 self.rank(),
173 self.size(),
174 AutomorphismKey::generate_from_sk_scratch_space(module, self.rank(), self.size())
175 )
176 }
177
178 let (sk_out_dft_data, scratch_1) = scratch.tmp_scalar_znx_dft(module, sk.rank());
179
180 let mut sk_out_dft: SecretKeyFourier<&mut [u8], FFT64> = SecretKeyFourier {
181 data: sk_out_dft_data,
182 dist: sk.dist,
183 };
184
185 {
186 (0..self.rank()).for_each(|i| {
187 let (mut sk_inv_auto, _) = scratch_1.tmp_scalar_znx(module, 1);
188 module.scalar_znx_automorphism(
189 module.galois_element_inv(p),
190 &mut sk_inv_auto,
191 0,
192 &sk.data,
193 i,
194 );
195 module.svp_prepare(&mut sk_out_dft.data, i, &sk_inv_auto, 0);
196 });
197 }
198
199 self.key.generate_from_sk(
200 module,
201 &sk,
202 &sk_out_dft,
203 source_xa,
204 source_xe,
205 sigma,
206 scratch_1,
207 );
208
209 self.p = p;
210 }
211}
212
213impl<DataSelf: AsMut<[u8]> + AsRef<[u8]>> AutomorphismKey<DataSelf, FFT64> {
214 pub fn automorphism<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
215 &mut self,
216 module: &Module<FFT64>,
217 lhs: &AutomorphismKey<DataLhs, FFT64>,
218 rhs: &AutomorphismKey<DataRhs, FFT64>,
219 scratch: &mut Scratch,
220 ) {
221 #[cfg(debug_assertions)]
222 {
223 assert_eq!(
224 self.rank_in(),
225 lhs.rank_in(),
226 "ksk_out input rank: {} != ksk_in input rank: {}",
227 self.rank_in(),
228 lhs.rank_in()
229 );
230 assert_eq!(
231 lhs.rank_out(),
232 rhs.rank_in(),
233 "ksk_in output rank: {} != ksk_apply input rank: {}",
234 self.rank_out(),
235 rhs.rank_in()
236 );
237 assert_eq!(
238 self.rank_out(),
239 rhs.rank_out(),
240 "ksk_out output rank: {} != ksk_apply output rank: {}",
241 self.rank_out(),
242 rhs.rank_out()
243 );
244 }
245
246 let cols_out: usize = rhs.rank_out() + 1;
247
248 let (tmp_dft_data, scratch1) = scratch.tmp_vec_znx_dft(module, cols_out, lhs.size());
249
250 let mut tmp_dft: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
251 data: tmp_dft_data,
252 basek: lhs.basek(),
253 k: lhs.k(),
254 };
255
256 (0..self.rank_in()).for_each(|col_i| {
257 (0..self.rows()).for_each(|row_j| {
258 // Extracts relevant row
259 lhs.get_row(module, row_j, col_i, &mut tmp_dft);
260
261 // Get a VecZnxBig from scratch space
262 let (mut tmp_idft_data, scratch2) = scratch1.tmp_vec_znx_big(module, cols_out, self.size());
263
264 // Switches input outside of DFT
265 (0..cols_out).for_each(|i| {
266 module.vec_znx_idft(&mut tmp_idft_data, i, &tmp_dft.data, i, scratch2);
267 });
268
269 // Consumes to small vec znx
270 let mut tmp_idft_small_data: VecZnx<&mut [u8]> = tmp_idft_data.to_vec_znx_small();
271
272 // Reverts the automorphis key from (-pi^{-1}_{k}(s)a + s, a) to (-sa + pi_{k}(s), a)
273 (0..cols_out).for_each(|i| {
274 module.vec_znx_automorphism_inplace(lhs.p(), &mut tmp_idft_small_data, i);
275 });
276
277 // Wraps into ciphertext
278 let mut tmp_idft: GLWECiphertext<&mut [u8]> = GLWECiphertext::<&mut [u8]> {
279 data: tmp_idft_small_data,
280 basek: self.basek(),
281 k: self.k(),
282 };
283
284 // Key-switch (-sa + pi_{k}(s), a) to (-pi^{-1}_{k'}(s)a + pi_{k}(s), a)
285 tmp_idft.keyswitch_inplace(module, &rhs.key, scratch2);
286
287 // Applies back the automorphism X^{k}: (-pi^{-1}_{k'}(s)a + pi_{k}(s), a) -> (-pi^{-1}_{k'+k}(s)a + s, a)
288 // and switches back to DFT domain
289 (0..self.rank_out() + 1).for_each(|i| {
290 module.vec_znx_automorphism_inplace(lhs.p(), &mut tmp_idft.data, i);
291 module.vec_znx_dft(&mut tmp_dft.data, i, &tmp_idft.data, i);
292 });
293
294 // Sets back the relevant row
295 self.set_row(module, row_j, col_i, &tmp_dft);
296 });
297 });
298
299 tmp_dft.data.zero();
300
301 (self.rows().min(lhs.rows())..self.rows()).for_each(|row_i| {
302 (0..self.rank_in()).for_each(|col_j| {
303 self.set_row(module, row_i, col_j, &tmp_dft);
304 });
305 });
306
307 self.p = (lhs.p * rhs.p) % (module.cyclotomic_order() as i64);
308 }
309
310 pub fn automorphism_inplace<DataRhs: AsRef<[u8]>>(
311 &mut self,
312 module: &Module<FFT64>,
313 rhs: &AutomorphismKey<DataRhs, FFT64>,
314 scratch: &mut Scratch,
315 ) {
316 unsafe {
317 let self_ptr: *mut AutomorphismKey<DataSelf, FFT64> = self as *mut AutomorphismKey<DataSelf, FFT64>;
318 self.automorphism(&module, &*self_ptr, rhs, scratch);
319 }
320 }
321
322 pub fn keyswitch<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
323 &mut self,
324 module: &Module<FFT64>,
325 lhs: &AutomorphismKey<DataLhs, FFT64>,
326 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
327 scratch: &mut Scratch,
328 ) {
329 self.key.keyswitch(module, &lhs.key, rhs, scratch);
330 }
331
332 pub fn keyswitch_inplace<DataRhs: AsRef<[u8]>>(
333 &mut self,
334 module: &Module<FFT64>,
335 rhs: &AutomorphismKey<DataRhs, FFT64>,
336 scratch: &mut Scratch,
337 ) {
338 self.key.keyswitch_inplace(module, &rhs.key, scratch);
339 }
340
341 pub fn external_product<DataLhs: AsRef<[u8]>, DataRhs: AsRef<[u8]>>(
342 &mut self,
343 module: &Module<FFT64>,
344 lhs: &AutomorphismKey<DataLhs, FFT64>,
345 rhs: &GGSWCiphertext<DataRhs, FFT64>,
346 scratch: &mut Scratch,
347 ) {
348 self.key.external_product(module, &lhs.key, rhs, scratch);
349 }
350
351 pub fn external_product_inplace<DataRhs: AsRef<[u8]>>(
352 &mut self,
353 module: &Module<FFT64>,
354 rhs: &GGSWCiphertext<DataRhs, FFT64>,
355 scratch: &mut Scratch,
356 ) {
357 self.key.external_product_inplace(module, rhs, scratch);
358 }
359}