poulpy/core/src/glwe_ciphertext.rs
core/src/glwe_ciphertext.rsRaw
1use backend::{
2 AddNormal, Backend, FFT64, FillUniform, MatZnxDft, MatZnxDftOps, MatZnxDftScratch, MatZnxDftToRef, Module, ScalarZnxAlloc,
3 ScalarZnxDft, ScalarZnxDftAlloc, ScalarZnxDftOps, ScalarZnxDftToRef, Scratch, VecZnx, VecZnxAlloc, VecZnxBig, VecZnxBigAlloc,
4 VecZnxBigOps, VecZnxBigScratch, VecZnxDft, VecZnxDftAlloc, VecZnxDftOps, VecZnxDftToMut, VecZnxDftToRef, VecZnxOps,
5 VecZnxToMut, VecZnxToRef, ZnxInfos, ZnxZero, copy_vec_znx_from,
6};
7use sampling::source::Source;
8
9use crate::{
10 SIX_SIGMA,
11 automorphism::AutomorphismKey,
12 elem::Infos,
13 ggsw_ciphertext::GGSWCiphertext,
14 glwe_ciphertext_fourier::GLWECiphertextFourier,
15 glwe_plaintext::GLWEPlaintext,
16 keys::{GLWEPublicKey, SecretDistribution, SecretKeyFourier},
17 keyswitch_key::GLWESwitchingKey,
18 utils::derive_size,
19};
20
21pub struct GLWECiphertext<C> {
22 pub data: VecZnx<C>,
23 pub basek: usize,
24 pub k: usize,
25}
26
27impl GLWECiphertext<Vec<u8>> {
28 pub fn alloc<B: Backend>(module: &Module<B>, basek: usize, k: usize, rank: usize) -> Self {
29 Self {
30 data: module.new_vec_znx(rank + 1, derive_size(basek, k)),
31 basek,
32 k,
33 }
34 }
35}
36
37impl<T> Infos for GLWECiphertext<T> {
38 type Inner = VecZnx<T>;
39
40 fn inner(&self) -> &Self::Inner {
41 &self.data
42 }
43
44 fn basek(&self) -> usize {
45 self.basek
46 }
47
48 fn k(&self) -> usize {
49 self.k
50 }
51}
52
53impl<T> GLWECiphertext<T> {
54 pub fn rank(&self) -> usize {
55 self.cols() - 1
56 }
57}
58
59impl<C> VecZnxToMut for GLWECiphertext<C>
60where
61 VecZnx<C>: VecZnxToMut,
62{
63 fn to_mut(&mut self) -> VecZnx<&mut [u8]> {
64 self.data.to_mut()
65 }
66}
67
68impl<C> VecZnxToRef for GLWECiphertext<C>
69where
70 VecZnx<C>: VecZnxToRef,
71{
72 fn to_ref(&self) -> VecZnx<&[u8]> {
73 self.data.to_ref()
74 }
75}
76
77impl<C> GLWECiphertext<C>
78where
79 VecZnx<C>: VecZnxToRef,
80{
81 #[allow(dead_code)]
82 pub(crate) fn dft<R>(&self, module: &Module<FFT64>, res: &mut GLWECiphertextFourier<R, FFT64>)
83 where
84 VecZnxDft<R, FFT64>: VecZnxDftToMut<FFT64> + ZnxInfos,
85 {
86 #[cfg(debug_assertions)]
87 {
88 assert_eq!(self.rank(), res.rank());
89 assert_eq!(self.basek(), res.basek())
90 }
91
92 (0..self.rank() + 1).for_each(|i| {
93 module.vec_znx_dft(res, i, self, i);
94 })
95 }
96}
97
98impl GLWECiphertext<Vec<u8>> {
99 pub fn encrypt_sk_scratch_space(module: &Module<FFT64>, ct_size: usize) -> usize {
100 module.vec_znx_big_normalize_tmp_bytes()
101 + module.bytes_of_vec_znx_dft(1, ct_size)
102 + module.bytes_of_vec_znx_big(1, ct_size)
103 }
104 pub fn encrypt_pk_scratch_space(module: &Module<FFT64>, pk_size: usize) -> usize {
105 ((module.bytes_of_vec_znx_dft(1, pk_size) + module.bytes_of_vec_znx_big(1, pk_size)) | module.bytes_of_scalar_znx(1))
106 + module.bytes_of_scalar_znx_dft(1)
107 + module.vec_znx_big_normalize_tmp_bytes()
108 }
109
110 pub fn decrypt_scratch_space(module: &Module<FFT64>, ct_size: usize) -> usize {
111 (module.vec_znx_big_normalize_tmp_bytes() | module.bytes_of_vec_znx_dft(1, ct_size))
112 + module.bytes_of_vec_znx_big(1, ct_size)
113 }
114
115 pub fn keyswitch_scratch_space(
116 module: &Module<FFT64>,
117 out_size: usize,
118 out_rank: usize,
119 in_size: usize,
120 in_rank: usize,
121 ksk_size: usize,
122 ) -> usize {
123 let res_dft: usize = module.bytes_of_vec_znx_dft(out_rank + 1, ksk_size);
124 let vmp: usize = module.vmp_apply_tmp_bytes(out_size, in_size, in_size, in_rank, out_rank + 1, ksk_size)
125 + module.bytes_of_vec_znx_dft(in_rank, in_size);
126 let normalize: usize = module.vec_znx_big_normalize_tmp_bytes();
127
128 return res_dft + (vmp | normalize);
129 }
130
131 pub fn keyswitch_from_fourier_scratch_space(
132 module: &Module<FFT64>,
133 out_size: usize,
134 out_rank: usize,
135 in_size: usize,
136 in_rank: usize,
137 ksk_size: usize,
138 ) -> usize {
139 let res_dft = module.bytes_of_vec_znx_dft(out_rank + 1, ksk_size);
140
141 let vmp: usize = module.vmp_apply_tmp_bytes(out_size, in_size, in_size, in_rank, out_rank + 1, ksk_size)
142 + module.bytes_of_vec_znx_dft(in_rank, in_size);
143
144 let norm: usize = module.vec_znx_big_normalize_tmp_bytes();
145
146 res_dft + (vmp | norm)
147 }
148
149 pub fn keyswitch_inplace_scratch_space(module: &Module<FFT64>, out_size: usize, out_rank: usize, ksk_size: usize) -> usize {
150 GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, out_size, out_rank, ksk_size)
151 }
152
153 pub fn automorphism_scratch_space(
154 module: &Module<FFT64>,
155 out_size: usize,
156 out_rank: usize,
157 in_size: usize,
158 autokey_size: usize,
159 ) -> usize {
160 GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, in_size, out_rank, autokey_size)
161 }
162
163 pub fn automorphism_inplace_scratch_space(
164 module: &Module<FFT64>,
165 out_size: usize,
166 out_rank: usize,
167 autokey_size: usize,
168 ) -> usize {
169 GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, out_size, out_rank, autokey_size)
170 }
171
172 pub fn external_product_scratch_space(
173 module: &Module<FFT64>,
174 out_size: usize,
175 out_rank: usize,
176 in_size: usize,
177 ggsw_size: usize,
178 ) -> usize {
179 let res_dft: usize = module.bytes_of_vec_znx_dft(out_rank + 1, ggsw_size);
180 let vmp: usize = module.bytes_of_vec_znx_dft(out_rank + 1, in_size)
181 + module.vmp_apply_tmp_bytes(
182 out_size,
183 in_size,
184 in_size, // rows
185 out_rank + 1, // cols in
186 out_rank + 1, // cols out
187 ggsw_size,
188 );
189 let normalize: usize = module.vec_znx_big_normalize_tmp_bytes();
190
191 res_dft + (vmp | normalize)
192 }
193
194 pub fn external_product_inplace_scratch_space(
195 module: &Module<FFT64>,
196 out_size: usize,
197 out_rank: usize,
198 ggsw_size: usize,
199 ) -> usize {
200 GLWECiphertext::external_product_scratch_space(module, out_size, out_rank, out_size, ggsw_size)
201 }
202}
203
204impl<DataSelf> GLWECiphertext<DataSelf>
205where
206 VecZnx<DataSelf>: VecZnxToMut + VecZnxToRef,
207{
208 pub fn encrypt_sk<DataPt, DataSk>(
209 &mut self,
210 module: &Module<FFT64>,
211 pt: &GLWEPlaintext<DataPt>,
212 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
213 source_xa: &mut Source,
214 source_xe: &mut Source,
215 sigma: f64,
216 scratch: &mut Scratch,
217 ) where
218 VecZnx<DataPt>: VecZnxToRef,
219 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
220 {
221 self.encrypt_sk_private(
222 module,
223 Some((pt, 0)),
224 sk_dft,
225 source_xa,
226 source_xe,
227 sigma,
228 scratch,
229 );
230 }
231
232 pub fn encrypt_zero_sk<DataSk>(
233 &mut self,
234 module: &Module<FFT64>,
235 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
236 source_xa: &mut Source,
237 source_xe: &mut Source,
238 sigma: f64,
239 scratch: &mut Scratch,
240 ) where
241 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
242 {
243 self.encrypt_sk_private(module, None, sk_dft, source_xa, source_xe, sigma, scratch);
244 }
245
246 pub fn encrypt_pk<DataPt, DataPk>(
247 &mut self,
248 module: &Module<FFT64>,
249 pt: &GLWEPlaintext<DataPt>,
250 pk: &GLWEPublicKey<DataPk, FFT64>,
251 source_xu: &mut Source,
252 source_xe: &mut Source,
253 sigma: f64,
254 scratch: &mut Scratch,
255 ) where
256 VecZnx<DataPt>: VecZnxToRef,
257 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
258 {
259 self.encrypt_pk_private(
260 module,
261 Some((pt, 0)),
262 pk,
263 source_xu,
264 source_xe,
265 sigma,
266 scratch,
267 );
268 }
269
270 pub fn encrypt_zero_pk<DataPk>(
271 &mut self,
272 module: &Module<FFT64>,
273 pk: &GLWEPublicKey<DataPk, FFT64>,
274 source_xu: &mut Source,
275 source_xe: &mut Source,
276 sigma: f64,
277 scratch: &mut Scratch,
278 ) where
279 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
280 {
281 self.encrypt_pk_private(module, None, pk, source_xu, source_xe, sigma, scratch);
282 }
283
284 pub fn copy<DataOther>(&mut self, other: &GLWECiphertext<DataOther>)
285 where
286 VecZnx<DataOther>: VecZnxToRef,
287 {
288 copy_vec_znx_from(&mut self.data.to_mut(), &other.to_ref());
289 self.k = other.k;
290 self.basek = other.basek;
291 }
292
293 pub fn rsh(&mut self, k: usize, scratch: &mut Scratch) {
294 let basek: usize = self.basek();
295 let mut self_mut: VecZnx<&mut [u8]> = self.data.to_mut();
296 self_mut.rsh(basek, k, scratch);
297 }
298
299 pub fn automorphism<DataLhs, DataRhs>(
300 &mut self,
301 module: &Module<FFT64>,
302 lhs: &GLWECiphertext<DataLhs>,
303 rhs: &AutomorphismKey<DataRhs, FFT64>,
304 scratch: &mut Scratch,
305 ) where
306 VecZnx<DataLhs>: VecZnxToRef,
307 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
308 {
309 self.keyswitch(module, lhs, &rhs.key, scratch);
310 (0..self.rank() + 1).for_each(|i| {
311 module.vec_znx_automorphism_inplace(rhs.p(), self, i);
312 })
313 }
314
315 pub fn automorphism_inplace<DataRhs>(
316 &mut self,
317 module: &Module<FFT64>,
318 rhs: &AutomorphismKey<DataRhs, FFT64>,
319 scratch: &mut Scratch,
320 ) where
321 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
322 {
323 self.keyswitch_inplace(module, &rhs.key, scratch);
324 (0..self.rank() + 1).for_each(|i| {
325 module.vec_znx_automorphism_inplace(rhs.p(), self, i);
326 })
327 }
328
329 pub fn automorphism_add<DataLhs, DataRhs>(
330 &mut self,
331 module: &Module<FFT64>,
332 lhs: &GLWECiphertext<DataLhs>,
333 rhs: &AutomorphismKey<DataRhs, FFT64>,
334 scratch: &mut Scratch,
335 ) where
336 VecZnx<DataLhs>: VecZnxToRef,
337 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
338 {
339 Self::keyswitch_private(self, true, rhs.p(), module, lhs, &rhs.key, scratch);
340 }
341
342 pub fn automorphism_add_inplace<DataRhs>(
343 &mut self,
344 module: &Module<FFT64>,
345 rhs: &AutomorphismKey<DataRhs, FFT64>,
346 scratch: &mut Scratch,
347 ) where
348 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
349 {
350 unsafe {
351 let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
352 Self::keyswitch_private(self, true, rhs.p(), module, &*self_ptr, &rhs.key, scratch);
353 }
354 }
355
356 pub(crate) fn keyswitch_from_fourier<DataLhs, DataRhs>(
357 &mut self,
358 module: &Module<FFT64>,
359 lhs: &GLWECiphertextFourier<DataLhs, FFT64>,
360 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
361 scratch: &mut Scratch,
362 ) where
363 VecZnxDft<DataLhs, FFT64>: VecZnxDftToRef<FFT64>,
364 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
365 {
366 let basek: usize = self.basek();
367
368 #[cfg(debug_assertions)]
369 {
370 assert_eq!(lhs.rank(), rhs.rank_in());
371 assert_eq!(self.rank(), rhs.rank_out());
372 assert_eq!(self.basek(), basek);
373 assert_eq!(lhs.basek(), basek);
374 assert_eq!(rhs.n(), module.n());
375 assert_eq!(self.n(), module.n());
376 assert_eq!(lhs.n(), module.n());
377 assert!(
378 scratch.available()
379 >= GLWECiphertext::keyswitch_from_fourier_scratch_space(
380 module,
381 self.size(),
382 self.rank(),
383 lhs.size(),
384 lhs.rank(),
385 rhs.size(),
386 )
387 );
388 }
389
390 let cols_in: usize = rhs.rank_in();
391 let cols_out: usize = rhs.rank_out() + 1;
392
393 // Buffer of the result of VMP in DFT
394 let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols_out, rhs.size()); // Todo optimise
395
396 {
397 // Applies VMP
398 let (mut ai_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols_in, lhs.size());
399 (0..cols_in).for_each(|col_i| {
400 module.vec_znx_dft_copy(&mut ai_dft, col_i, lhs, col_i + 1);
401 });
402 module.vmp_apply(&mut res_dft, &ai_dft, rhs, scratch2);
403 }
404
405 module.vec_znx_dft_add_inplace(&mut res_dft, 0, lhs, 0);
406
407 // Switches result of VMP outside of DFT
408 let res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume::<&mut [u8]>(res_dft);
409
410 (0..cols_out).for_each(|i| {
411 module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
412 });
413 }
414
415 pub fn keyswitch<DataLhs, DataRhs>(
416 &mut self,
417 module: &Module<FFT64>,
418 lhs: &GLWECiphertext<DataLhs>,
419 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
420 scratch: &mut Scratch,
421 ) where
422 VecZnx<DataLhs>: VecZnxToRef,
423 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
424 {
425 Self::keyswitch_private(self, false, 0, module, lhs, rhs, scratch);
426 }
427
428 pub(crate) fn keyswitch_private<DataLhs, DataRhs>(
429 &mut self,
430 add_self: bool,
431 apply_auto: i64,
432 module: &Module<FFT64>,
433 lhs: &GLWECiphertext<DataLhs>,
434 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
435 scratch: &mut Scratch,
436 ) where
437 VecZnx<DataLhs>: VecZnxToRef,
438 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
439 {
440 let basek: usize = self.basek();
441
442 #[cfg(debug_assertions)]
443 {
444 assert_eq!(lhs.rank(), rhs.rank_in());
445 assert_eq!(self.rank(), rhs.rank_out());
446 assert_eq!(self.basek(), basek);
447 assert_eq!(lhs.basek(), basek);
448 assert_eq!(rhs.n(), module.n());
449 assert_eq!(self.n(), module.n());
450 assert_eq!(lhs.n(), module.n());
451 assert!(
452 scratch.available()
453 >= GLWECiphertext::keyswitch_scratch_space(
454 module,
455 self.size(),
456 self.rank(),
457 lhs.size(),
458 lhs.rank(),
459 rhs.size(),
460 )
461 );
462 }
463
464 let cols_in: usize = rhs.rank_in();
465 let cols_out: usize = rhs.rank_out() + 1;
466
467 let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols_out, rhs.size()); // Todo optimise
468
469 {
470 let (mut ai_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols_in, lhs.size());
471 (0..cols_in).for_each(|col_i| {
472 module.vec_znx_dft(&mut ai_dft, col_i, lhs, col_i + 1);
473 });
474 module.vmp_apply(&mut res_dft, &ai_dft, rhs, scratch2);
475 }
476
477 let mut res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(res_dft);
478
479 module.vec_znx_big_add_small_inplace(&mut res_big, 0, lhs, 0);
480
481 (0..cols_out).for_each(|i| {
482 if apply_auto != 0 {
483 module.vec_znx_big_automorphism_inplace(apply_auto, &mut res_big, i);
484 }
485
486 if add_self {
487 module.vec_znx_big_add_small_inplace(&mut res_big, i, lhs, i);
488 }
489 module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
490 });
491 }
492
493 pub fn keyswitch_inplace<DataRhs>(
494 &mut self,
495 module: &Module<FFT64>,
496 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
497 scratch: &mut Scratch,
498 ) where
499 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
500 {
501 unsafe {
502 let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
503 self.keyswitch(&module, &*self_ptr, rhs, scratch);
504 }
505 }
506
507 pub fn external_product<DataLhs, DataRhs>(
508 &mut self,
509 module: &Module<FFT64>,
510 lhs: &GLWECiphertext<DataLhs>,
511 rhs: &GGSWCiphertext<DataRhs, FFT64>,
512 scratch: &mut Scratch,
513 ) where
514 VecZnx<DataLhs>: VecZnxToRef,
515 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
516 {
517 let basek: usize = self.basek();
518
519 #[cfg(debug_assertions)]
520 {
521 assert_eq!(rhs.rank(), lhs.rank());
522 assert_eq!(rhs.rank(), self.rank());
523 assert_eq!(self.basek(), basek);
524 assert_eq!(lhs.basek(), basek);
525 assert_eq!(rhs.n(), module.n());
526 assert_eq!(self.n(), module.n());
527 assert_eq!(lhs.n(), module.n());
528 }
529
530 let cols: usize = rhs.rank() + 1;
531
532 let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols, rhs.size()); // Todo optimise
533
534 {
535 let (mut a_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols, lhs.size());
536 (0..cols).for_each(|col_i| {
537 module.vec_znx_dft(&mut a_dft, col_i, lhs, col_i);
538 });
539 module.vmp_apply(&mut res_dft, &a_dft, rhs, scratch2);
540 }
541
542 let res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(res_dft);
543
544 (0..cols).for_each(|i| {
545 module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
546 });
547 }
548
549 pub fn external_product_inplace<DataRhs>(
550 &mut self,
551 module: &Module<FFT64>,
552 rhs: &GGSWCiphertext<DataRhs, FFT64>,
553 scratch: &mut Scratch,
554 ) where
555 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
556 {
557 unsafe {
558 let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
559 self.external_product(&module, &*self_ptr, rhs, scratch);
560 }
561 }
562
563 pub(crate) fn encrypt_sk_private<DataPt, DataSk>(
564 &mut self,
565 module: &Module<FFT64>,
566 pt: Option<(&GLWEPlaintext<DataPt>, usize)>,
567 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
568 source_xa: &mut Source,
569 source_xe: &mut Source,
570 sigma: f64,
571 scratch: &mut Scratch,
572 ) where
573 VecZnx<DataPt>: VecZnxToRef,
574 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
575 {
576 #[cfg(debug_assertions)]
577 {
578 assert_eq!(self.rank(), sk_dft.rank());
579 assert_eq!(sk_dft.n(), module.n());
580 assert_eq!(self.n(), module.n());
581 if let Some((pt, col)) = pt {
582 assert_eq!(pt.n(), module.n());
583 assert!(col < self.rank() + 1);
584 }
585 }
586
587 let basek: usize = self.basek();
588 let k: usize = self.k();
589 let size: usize = self.size();
590 let cols: usize = self.rank() + 1;
591
592 let (mut c0_big, scratch_1) = scratch.tmp_vec_znx(module, 1, size);
593 c0_big.zero();
594
595 {
596 // c[i] = uniform
597 // c[0] -= c[i] * s[i],
598 (1..cols).for_each(|i| {
599 let (mut ci_dft, scratch_2) = scratch_1.tmp_vec_znx_dft(module, 1, size);
600
601 // c[i] = uniform
602 self.data.fill_uniform(basek, i, size, source_xa);
603
604 // c[i] = norm(IDFT(DFT(c[i]) * DFT(s[i])))
605 module.vec_znx_dft(&mut ci_dft, 0, self, i);
606 module.svp_apply_inplace(&mut ci_dft, 0, sk_dft, i - 1);
607 let ci_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(ci_dft);
608
609 // use c[0] as buffer, which is overwritten later by the normalization step
610 module.vec_znx_big_normalize(basek, self, 0, &ci_big, 0, scratch_2);
611
612 // c0_tmp = -c[i] * s[i] (use c[0] as buffer)
613 module.vec_znx_sub_ab_inplace(&mut c0_big, 0, self, 0);
614
615 // c[i] += m if col = i
616 if let Some((pt, col)) = pt {
617 if i == col {
618 module.vec_znx_add_inplace(self, i, pt, 0);
619 module.vec_znx_normalize_inplace(basek, self, i, scratch_2);
620 }
621 }
622 });
623 }
624
625 // c[0] += e
626 c0_big.add_normal(basek, 0, k, source_xe, sigma, sigma * SIX_SIGMA);
627
628 // c[0] += m if col = 0
629 if let Some((pt, col)) = pt {
630 if col == 0 {
631 module.vec_znx_add_inplace(&mut c0_big, 0, pt, 0);
632 }
633 }
634
635 // c[0] = norm(c[0])
636 module.vec_znx_normalize(basek, self, 0, &c0_big, 0, scratch_1);
637 }
638
639 pub(crate) fn encrypt_pk_private<DataPt, DataPk>(
640 &mut self,
641 module: &Module<FFT64>,
642 pt: Option<(&GLWEPlaintext<DataPt>, usize)>,
643 pk: &GLWEPublicKey<DataPk, FFT64>,
644 source_xu: &mut Source,
645 source_xe: &mut Source,
646 sigma: f64,
647 scratch: &mut Scratch,
648 ) where
649 VecZnx<DataPt>: VecZnxToRef,
650 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
651 {
652 #[cfg(debug_assertions)]
653 {
654 assert_eq!(self.basek(), pk.basek());
655 assert_eq!(self.n(), module.n());
656 assert_eq!(pk.n(), module.n());
657 assert_eq!(self.rank(), pk.rank());
658 if let Some((pt, _)) = pt {
659 assert_eq!(pt.basek(), pk.basek());
660 assert_eq!(pt.n(), module.n());
661 }
662 }
663
664 let basek: usize = pk.basek();
665 let size_pk: usize = pk.size();
666 let cols: usize = self.rank() + 1;
667
668 // Generates u according to the underlying secret distribution.
669 let (mut u_dft, scratch_1) = scratch.tmp_scalar_znx_dft(module, 1);
670
671 {
672 let (mut u, _) = scratch_1.tmp_scalar_znx(module, 1);
673 match pk.dist {
674 SecretDistribution::NONE => panic!(
675 "invalid public key: SecretDistribution::NONE, ensure it has been correctly intialized through \
676 Self::generate"
677 ),
678 SecretDistribution::TernaryFixed(hw) => u.fill_ternary_hw(0, hw, source_xu),
679 SecretDistribution::TernaryProb(prob) => u.fill_ternary_prob(0, prob, source_xu),
680 SecretDistribution::ZERO => {}
681 }
682
683 module.svp_prepare(&mut u_dft, 0, &u, 0);
684 }
685
686 // ct[i] = pk[i] * u + ei (+ m if col = i)
687 (0..cols).for_each(|i| {
688 let (mut ci_dft, scratch_2) = scratch_1.tmp_vec_znx_dft(module, 1, size_pk);
689 // ci_dft = DFT(u) * DFT(pk[i])
690 module.svp_apply(&mut ci_dft, 0, &u_dft, 0, pk, i);
691
692 // ci_big = u * p[i]
693 let mut ci_big = module.vec_znx_idft_consume(ci_dft);
694
695 // ci_big = u * pk[i] + e
696 ci_big.add_normal(basek, 0, pk.k(), source_xe, sigma, sigma * SIX_SIGMA);
697
698 // ci_big = u * pk[i] + e + m (if col = i)
699 if let Some((pt, col)) = pt {
700 if col == i {
701 module.vec_znx_big_add_small_inplace(&mut ci_big, 0, pt, 0);
702 }
703 }
704
705 // ct[i] = norm(ci_big)
706 module.vec_znx_big_normalize(basek, self, i, &ci_big, 0, scratch_2);
707 });
708 }
709}
710
711impl<DataSelf> GLWECiphertext<DataSelf>
712where
713 VecZnx<DataSelf>: VecZnxToRef,
714{
715 pub fn decrypt<DataPt, DataSk>(
716 &self,
717 module: &Module<FFT64>,
718 pt: &mut GLWEPlaintext<DataPt>,
719 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
720 scratch: &mut Scratch,
721 ) where
722 VecZnx<DataPt>: VecZnxToMut,
723 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
724 {
725 #[cfg(debug_assertions)]
726 {
727 assert_eq!(self.rank(), sk_dft.rank());
728 assert_eq!(self.n(), module.n());
729 assert_eq!(pt.n(), module.n());
730 assert_eq!(sk_dft.n(), module.n());
731 }
732
733 let cols: usize = self.rank() + 1;
734
735 let (mut c0_big, scratch_1) = scratch.tmp_vec_znx_big(module, 1, self.size()); // TODO optimize size when pt << ct
736 c0_big.zero();
737
738 {
739 (1..cols).for_each(|i| {
740 // ci_dft = DFT(a[i]) * DFT(s[i])
741 let (mut ci_dft, _) = scratch_1.tmp_vec_znx_dft(module, 1, self.size()); // TODO optimize size when pt << ct
742 module.vec_znx_dft(&mut ci_dft, 0, self, i);
743 module.svp_apply_inplace(&mut ci_dft, 0, sk_dft, i - 1);
744 let ci_big = module.vec_znx_idft_consume(ci_dft);
745
746 // c0_big += a[i] * s[i]
747 module.vec_znx_big_add_inplace(&mut c0_big, 0, &ci_big, 0);
748 });
749 }
750
751 // c0_big = (a * s) + (-a * s + m + e) = BIG(m + e)
752 module.vec_znx_big_add_small_inplace(&mut c0_big, 0, self, 0);
753
754 // pt = norm(BIG(m + e))
755 module.vec_znx_big_normalize(self.basek(), pt, 0, &mut c0_big, 0, scratch_1);
756
757 pt.basek = self.basek();
758 pt.k = pt.k().min(self.k());
759 }
760}