poulpy/core/src/glwe_ciphertext.rs
core/src/glwe_ciphertext.rsRaw
1use base2k::{
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,
6};
7use sampling::source::Source;
8
9use crate::{
10 SIX_SIGMA,
11 elem::Infos,
12 ggsw_ciphertext::GGSWCiphertext,
13 glwe_ciphertext_fourier::GLWECiphertextFourier,
14 glwe_plaintext::GLWEPlaintext,
15 keys::{GLWEPublicKey, SecretDistribution, SecretKeyFourier},
16 keyswitch_key::GLWESwitchingKey,
17 utils::derive_size,
18};
19
20pub struct GLWECiphertext<C> {
21 pub data: VecZnx<C>,
22 pub basek: usize,
23 pub k: usize,
24}
25
26impl GLWECiphertext<Vec<u8>> {
27 pub fn new<B: Backend>(module: &Module<B>, basek: usize, k: usize, rank: usize) -> Self {
28 Self {
29 data: module.new_vec_znx(rank + 1, derive_size(basek, k)),
30 basek,
31 k,
32 }
33 }
34}
35
36impl<T> Infos for GLWECiphertext<T> {
37 type Inner = VecZnx<T>;
38
39 fn inner(&self) -> &Self::Inner {
40 &self.data
41 }
42
43 fn basek(&self) -> usize {
44 self.basek
45 }
46
47 fn k(&self) -> usize {
48 self.k
49 }
50}
51
52impl<T> GLWECiphertext<T> {
53 pub fn rank(&self) -> usize {
54 self.cols() - 1
55 }
56}
57
58impl<C> VecZnxToMut for GLWECiphertext<C>
59where
60 VecZnx<C>: VecZnxToMut,
61{
62 fn to_mut(&mut self) -> VecZnx<&mut [u8]> {
63 self.data.to_mut()
64 }
65}
66
67impl<C> VecZnxToRef for GLWECiphertext<C>
68where
69 VecZnx<C>: VecZnxToRef,
70{
71 fn to_ref(&self) -> VecZnx<&[u8]> {
72 self.data.to_ref()
73 }
74}
75
76impl<C> GLWECiphertext<C>
77where
78 VecZnx<C>: VecZnxToRef,
79{
80 #[allow(dead_code)]
81 pub(crate) fn dft<R>(&self, module: &Module<FFT64>, res: &mut GLWECiphertextFourier<R, FFT64>)
82 where
83 VecZnxDft<R, FFT64>: VecZnxDftToMut<FFT64> + ZnxInfos,
84 {
85 #[cfg(debug_assertions)]
86 {
87 assert_eq!(self.rank(), res.rank());
88 assert_eq!(self.basek(), res.basek())
89 }
90
91 (0..self.rank() + 1).for_each(|i| {
92 module.vec_znx_dft(res, i, self, i);
93 })
94 }
95}
96
97impl GLWECiphertext<Vec<u8>> {
98 pub fn encrypt_sk_scratch_space(module: &Module<FFT64>, ct_size: usize) -> usize {
99 module.vec_znx_big_normalize_tmp_bytes()
100 + module.bytes_of_vec_znx_dft(1, ct_size)
101 + module.bytes_of_vec_znx_big(1, ct_size)
102 }
103 pub fn encrypt_pk_scratch_space(module: &Module<FFT64>, pk_size: usize) -> usize {
104 ((module.bytes_of_vec_znx_dft(1, pk_size) + module.bytes_of_vec_znx_big(1, pk_size)) | module.bytes_of_scalar_znx(1))
105 + module.bytes_of_scalar_znx_dft(1)
106 + module.vec_znx_big_normalize_tmp_bytes()
107 }
108
109 pub fn decrypt_scratch_space(module: &Module<FFT64>, ct_size: usize) -> usize {
110 (module.vec_znx_big_normalize_tmp_bytes() | module.bytes_of_vec_znx_dft(1, ct_size))
111 + module.bytes_of_vec_znx_big(1, ct_size)
112 }
113
114 pub fn keyswitch_scratch_space(
115 module: &Module<FFT64>,
116 out_size: usize,
117 out_rank: usize,
118 in_size: usize,
119 in_rank: usize,
120 ksk_size: usize,
121 ) -> usize {
122 module.bytes_of_vec_znx_dft(out_rank + 1, ksk_size)
123 + (module.vec_znx_big_normalize_tmp_bytes()
124 | (module.vmp_apply_tmp_bytes(
125 out_size,
126 in_size,
127 in_size,
128 in_rank + 1,
129 out_rank + 1,
130 ksk_size,
131 ) + module.bytes_of_vec_znx_dft(in_size, in_size)))
132 }
133
134 pub fn keyswitch_inplace_scratch_space(module: &Module<FFT64>, out_size: usize, out_rank: usize, ksk_size: usize) -> usize {
135 GLWECiphertext::keyswitch_scratch_space(module, out_size, out_rank, out_size, out_rank, ksk_size)
136 }
137
138 pub fn external_product_scratch_space(
139 module: &Module<FFT64>,
140 out_size: usize,
141 in_size: usize,
142 ggsw_size: usize,
143 rank: usize,
144 ) -> usize {
145 module.bytes_of_vec_znx_dft(rank + 1, ggsw_size)
146 + ((module.bytes_of_vec_znx_dft(rank + 1, in_size)
147 + module.vmp_apply_tmp_bytes(
148 out_size,
149 in_size,
150 in_size, // rows
151 rank + 1, // cols in
152 rank + 1, // cols out
153 ggsw_size,
154 ))
155 | module.vec_znx_big_normalize_tmp_bytes())
156 }
157
158 pub fn external_product_inplace_scratch_space(module: &Module<FFT64>, res_size: usize, rhs: usize, rank: usize) -> usize {
159 GLWECiphertext::external_product_scratch_space(module, res_size, res_size, rhs, rank)
160 }
161}
162
163impl<DataSelf> GLWECiphertext<DataSelf>
164where
165 VecZnx<DataSelf>: VecZnxToMut + VecZnxToRef,
166{
167 pub fn encrypt_sk<DataPt, DataSk>(
168 &mut self,
169 module: &Module<FFT64>,
170 pt: &GLWEPlaintext<DataPt>,
171 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
172 source_xa: &mut Source,
173 source_xe: &mut Source,
174 sigma: f64,
175 scratch: &mut Scratch,
176 ) where
177 VecZnx<DataPt>: VecZnxToRef,
178 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
179 {
180 self.encrypt_sk_private(
181 module,
182 Some((pt, 0)),
183 sk_dft,
184 source_xa,
185 source_xe,
186 sigma,
187 scratch,
188 );
189 }
190
191 pub fn encrypt_zero_sk<DataSk>(
192 &mut self,
193 module: &Module<FFT64>,
194 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
195 source_xa: &mut Source,
196 source_xe: &mut Source,
197 sigma: f64,
198 scratch: &mut Scratch,
199 ) where
200 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
201 {
202 self.encrypt_sk_private(module, None, sk_dft, source_xa, source_xe, sigma, scratch);
203 }
204
205 pub fn encrypt_pk<DataPt, DataPk>(
206 &mut self,
207 module: &Module<FFT64>,
208 pt: &GLWEPlaintext<DataPt>,
209 pk: &GLWEPublicKey<DataPk, FFT64>,
210 source_xu: &mut Source,
211 source_xe: &mut Source,
212 sigma: f64,
213 scratch: &mut Scratch,
214 ) where
215 VecZnx<DataPt>: VecZnxToRef,
216 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
217 {
218 self.encrypt_pk_private(
219 module,
220 Some((pt, 0)),
221 pk,
222 source_xu,
223 source_xe,
224 sigma,
225 scratch,
226 );
227 }
228
229 pub fn encrypt_zero_pk<DataPk>(
230 &mut self,
231 module: &Module<FFT64>,
232 pk: &GLWEPublicKey<DataPk, FFT64>,
233 source_xu: &mut Source,
234 source_xe: &mut Source,
235 sigma: f64,
236 scratch: &mut Scratch,
237 ) where
238 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
239 {
240 self.encrypt_pk_private(module, None, pk, source_xu, source_xe, sigma, scratch);
241 }
242
243 pub fn keyswitch<DataLhs, DataRhs>(
244 &mut self,
245 module: &Module<FFT64>,
246 lhs: &GLWECiphertext<DataLhs>,
247 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
248 scratch: &mut Scratch,
249 ) where
250 VecZnx<DataLhs>: VecZnxToRef,
251 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
252 {
253 let basek: usize = self.basek();
254
255 #[cfg(debug_assertions)]
256 {
257 assert_eq!(lhs.rank(), rhs.rank_in());
258 assert_eq!(self.rank(), rhs.rank_out());
259 assert_eq!(self.basek(), basek);
260 assert_eq!(lhs.basek(), basek);
261 assert_eq!(rhs.n(), module.n());
262 assert_eq!(self.n(), module.n());
263 assert_eq!(lhs.n(), module.n());
264 assert!(
265 scratch.available()
266 >= GLWECiphertext::keyswitch_scratch_space(
267 module,
268 self.size(),
269 self.rank(),
270 lhs.size(),
271 lhs.rank(),
272 rhs.size(),
273 )
274 );
275 }
276
277 let cols_in: usize = rhs.rank_in();
278 let cols_out: usize = rhs.rank_out() + 1;
279
280 let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols_out, rhs.size()); // Todo optimise
281
282 {
283 let (mut ai_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols_in, lhs.size());
284 (0..cols_in).for_each(|col_i| {
285 module.vec_znx_dft(&mut ai_dft, col_i, lhs, col_i + 1);
286 });
287 module.vmp_apply(&mut res_dft, &ai_dft, rhs, scratch2);
288 }
289
290 let mut res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(res_dft);
291
292 module.vec_znx_big_add_small_inplace(&mut res_big, 0, lhs, 0);
293
294 (0..cols_out).for_each(|i| {
295 module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
296 });
297 }
298
299 pub fn keyswitch_inplace<DataRhs>(
300 &mut self,
301 module: &Module<FFT64>,
302 rhs: &GLWESwitchingKey<DataRhs, FFT64>,
303 scratch: &mut Scratch,
304 ) where
305 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
306 {
307 unsafe {
308 let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
309 self.keyswitch(&module, &*self_ptr, rhs, scratch);
310 }
311 }
312
313 pub fn external_product<DataLhs, DataRhs>(
314 &mut self,
315 module: &Module<FFT64>,
316 lhs: &GLWECiphertext<DataLhs>,
317 rhs: &GGSWCiphertext<DataRhs, FFT64>,
318 scratch: &mut Scratch,
319 ) where
320 VecZnx<DataLhs>: VecZnxToRef,
321 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
322 {
323 let basek: usize = self.basek();
324
325 #[cfg(debug_assertions)]
326 {
327 assert_eq!(rhs.rank(), lhs.rank());
328 assert_eq!(rhs.rank(), self.rank());
329 assert_eq!(self.basek(), basek);
330 assert_eq!(lhs.basek(), basek);
331 assert_eq!(rhs.n(), module.n());
332 assert_eq!(self.n(), module.n());
333 assert_eq!(lhs.n(), module.n());
334 }
335
336 let cols: usize = rhs.rank() + 1;
337
338 let (mut res_dft, scratch1) = scratch.tmp_vec_znx_dft(module, cols, rhs.size()); // Todo optimise
339
340 {
341 let (mut a_dft, scratch2) = scratch1.tmp_vec_znx_dft(module, cols, lhs.size());
342 (0..cols).for_each(|col_i| {
343 module.vec_znx_dft(&mut a_dft, col_i, lhs, col_i);
344 });
345 module.vmp_apply(&mut res_dft, &a_dft, rhs, scratch2);
346 }
347
348 let res_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(res_dft);
349
350 (0..cols).for_each(|i| {
351 module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
352 });
353 }
354
355 pub fn external_product_inplace<DataRhs>(
356 &mut self,
357 module: &Module<FFT64>,
358 rhs: &GGSWCiphertext<DataRhs, FFT64>,
359 scratch: &mut Scratch,
360 ) where
361 MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
362 {
363 unsafe {
364 let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
365 self.external_product(&module, &*self_ptr, rhs, scratch);
366 }
367 }
368
369 pub(crate) fn encrypt_sk_private<DataPt, DataSk>(
370 &mut self,
371 module: &Module<FFT64>,
372 pt: Option<(&GLWEPlaintext<DataPt>, usize)>,
373 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
374 source_xa: &mut Source,
375 source_xe: &mut Source,
376 sigma: f64,
377 scratch: &mut Scratch,
378 ) where
379 VecZnx<DataPt>: VecZnxToRef,
380 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
381 {
382 #[cfg(debug_assertions)]
383 {
384 assert_eq!(self.rank(), sk_dft.rank());
385 assert_eq!(sk_dft.n(), module.n());
386 assert_eq!(self.n(), module.n());
387 if let Some((pt, col)) = pt {
388 assert_eq!(pt.n(), module.n());
389 assert!(col < self.rank() + 1);
390 }
391 }
392
393 let log_base2k: usize = self.basek();
394 let log_k: usize = self.k();
395 let size: usize = self.size();
396 let cols: usize = self.rank() + 1;
397
398 let (mut c0_big, scratch_1) = scratch.tmp_vec_znx(module, 1, size);
399 c0_big.zero();
400
401 {
402 // c[i] = uniform
403 // c[0] -= c[i] * s[i],
404 (1..cols).for_each(|i| {
405 let (mut ci_dft, scratch_2) = scratch_1.tmp_vec_znx_dft(module, 1, size);
406
407 // c[i] = uniform
408 self.data.fill_uniform(log_base2k, i, size, source_xa);
409
410 // c[i] = norm(IDFT(DFT(c[i]) * DFT(s[i])))
411 module.vec_znx_dft(&mut ci_dft, 0, self, i);
412 module.svp_apply_inplace(&mut ci_dft, 0, sk_dft, i - 1);
413 let ci_big: VecZnxBig<&mut [u8], FFT64> = module.vec_znx_idft_consume(ci_dft);
414
415 // use c[0] as buffer, which is overwritten later by the normalization step
416 module.vec_znx_big_normalize(log_base2k, self, 0, &ci_big, 0, scratch_2);
417
418 // c0_tmp = -c[i] * s[i] (use c[0] as buffer)
419 module.vec_znx_sub_ab_inplace(&mut c0_big, 0, self, 0);
420
421 // c[i] += m if col = i
422 if let Some((pt, col)) = pt {
423 if i == col {
424 module.vec_znx_add_inplace(self, i, pt, 0);
425 module.vec_znx_normalize_inplace(log_base2k, self, i, scratch_2);
426 }
427 }
428 });
429 }
430
431 // c[0] += e
432 c0_big.add_normal(log_base2k, 0, log_k, source_xe, sigma, sigma * SIX_SIGMA);
433
434 // c[0] += m if col = 0
435 if let Some((pt, col)) = pt {
436 if col == 0 {
437 module.vec_znx_add_inplace(&mut c0_big, 0, pt, 0);
438 }
439 }
440
441 // c[0] = norm(c[0])
442 module.vec_znx_normalize(log_base2k, self, 0, &c0_big, 0, scratch_1);
443 }
444
445 pub(crate) fn encrypt_pk_private<DataPt, DataPk>(
446 &mut self,
447 module: &Module<FFT64>,
448 pt: Option<(&GLWEPlaintext<DataPt>, usize)>,
449 pk: &GLWEPublicKey<DataPk, FFT64>,
450 source_xu: &mut Source,
451 source_xe: &mut Source,
452 sigma: f64,
453 scratch: &mut Scratch,
454 ) where
455 VecZnx<DataPt>: VecZnxToRef,
456 VecZnxDft<DataPk, FFT64>: VecZnxDftToRef<FFT64>,
457 {
458 #[cfg(debug_assertions)]
459 {
460 assert_eq!(self.basek(), pk.basek());
461 assert_eq!(self.n(), module.n());
462 assert_eq!(pk.n(), module.n());
463 assert_eq!(self.rank(), pk.rank());
464 if let Some((pt, _)) = pt {
465 assert_eq!(pt.basek(), pk.basek());
466 assert_eq!(pt.n(), module.n());
467 }
468 }
469
470 let log_base2k: usize = pk.basek();
471 let size_pk: usize = pk.size();
472 let cols: usize = self.rank() + 1;
473
474 // Generates u according to the underlying secret distribution.
475 let (mut u_dft, scratch_1) = scratch.tmp_scalar_znx_dft(module, 1);
476
477 {
478 let (mut u, _) = scratch_1.tmp_scalar_znx(module, 1);
479 match pk.dist {
480 SecretDistribution::NONE => panic!(
481 "invalid public key: SecretDistribution::NONE, ensure it has been correctly intialized through \
482 Self::generate"
483 ),
484 SecretDistribution::TernaryFixed(hw) => u.fill_ternary_hw(0, hw, source_xu),
485 SecretDistribution::TernaryProb(prob) => u.fill_ternary_prob(0, prob, source_xu),
486 SecretDistribution::ZERO => {}
487 }
488
489 module.svp_prepare(&mut u_dft, 0, &u, 0);
490 }
491
492 // ct[i] = pk[i] * u + ei (+ m if col = i)
493 (0..cols).for_each(|i| {
494 let (mut ci_dft, scratch_2) = scratch_1.tmp_vec_znx_dft(module, 1, size_pk);
495 // ci_dft = DFT(u) * DFT(pk[i])
496 module.svp_apply(&mut ci_dft, 0, &u_dft, 0, pk, i);
497
498 // ci_big = u * p[i]
499 let mut ci_big = module.vec_znx_idft_consume(ci_dft);
500
501 // ci_big = u * pk[i] + e
502 ci_big.add_normal(log_base2k, 0, pk.k(), source_xe, sigma, sigma * SIX_SIGMA);
503
504 // ci_big = u * pk[i] + e + m (if col = i)
505 if let Some((pt, col)) = pt {
506 if col == i {
507 module.vec_znx_big_add_small_inplace(&mut ci_big, 0, pt, 0);
508 }
509 }
510
511 // ct[i] = norm(ci_big)
512 module.vec_znx_big_normalize(log_base2k, self, i, &ci_big, 0, scratch_2);
513 });
514 }
515}
516
517impl<DataSelf> GLWECiphertext<DataSelf>
518where
519 VecZnx<DataSelf>: VecZnxToRef,
520{
521 pub fn decrypt<DataPt, DataSk>(
522 &self,
523 module: &Module<FFT64>,
524 pt: &mut GLWEPlaintext<DataPt>,
525 sk_dft: &SecretKeyFourier<DataSk, FFT64>,
526 scratch: &mut Scratch,
527 ) where
528 VecZnx<DataPt>: VecZnxToMut,
529 ScalarZnxDft<DataSk, FFT64>: ScalarZnxDftToRef<FFT64>,
530 {
531 #[cfg(debug_assertions)]
532 {
533 assert_eq!(self.rank(), sk_dft.rank());
534 assert_eq!(self.n(), module.n());
535 assert_eq!(pt.n(), module.n());
536 assert_eq!(sk_dft.n(), module.n());
537 }
538
539 let cols: usize = self.rank() + 1;
540
541 let (mut c0_big, scratch_1) = scratch.tmp_vec_znx_big(module, 1, self.size()); // TODO optimize size when pt << ct
542 c0_big.zero();
543
544 {
545 (1..cols).for_each(|i| {
546 // ci_dft = DFT(a[i]) * DFT(s[i])
547 let (mut ci_dft, _) = scratch_1.tmp_vec_znx_dft(module, 1, self.size()); // TODO optimize size when pt << ct
548 module.vec_znx_dft(&mut ci_dft, 0, self, i);
549 module.svp_apply_inplace(&mut ci_dft, 0, sk_dft, i - 1);
550 let ci_big = module.vec_znx_idft_consume(ci_dft);
551
552 // c0_big += a[i] * s[i]
553 module.vec_znx_big_add_inplace(&mut c0_big, 0, &ci_big, 0);
554 });
555 }
556
557 // c0_big = (a * s) + (-a * s + m + e) = BIG(m + e)
558 module.vec_znx_big_add_small_inplace(&mut c0_big, 0, self, 0);
559
560 // pt = norm(BIG(m + e))
561 module.vec_znx_big_normalize(self.basek(), pt, 0, &mut c0_big, 0, scratch_1);
562
563 pt.basek = self.basek();
564 pt.k = pt.k().min(self.k());
565 }
566}