phantom-zone/src/bool/evaluator.rs
src/bool/evaluator.rsRaw
1use std::{
2 collections::HashMap,
3 fmt::{Debug, Display},
4 marker::PhantomData,
5 usize,
6};
7
8use itertools::{izip, Itertools};
9use num_traits::{FromPrimitive, One, PrimInt, ToPrimitive, WrappingAdd, WrappingSub, Zero};
10use rand_distr::uniform::SampleUniform;
11
12use crate::{
13 backend::{ArithmeticOps, GetModulus, ModInit, Modulus, ShoupMatrixFMA, VectorOps},
14 bool::parameters::ParameterVariant,
15 decomposer::{Decomposer, DefaultDecomposer, NumInfo, RlweDecomposer},
16 lwe::{decrypt_lwe, encrypt_lwe, seeded_lwe_ksk_keygen},
17 multi_party::{
18 non_interactive_ksk_gen, non_interactive_ksk_zero_encryptions_for_other_party_i,
19 public_key_share,
20 },
21 ntt::{Ntt, NttInit},
22 pbs::{pbs, PbsInfo, PbsKey, WithShoupRepr},
23 random::{
24 DefaultSecureRng, NewWithSeed, RandomFill, RandomFillGaussianInModulus,
25 RandomFillUniformInModulus, RandomGaussianElementInModulus,
26 },
27 rgsw::{
28 generate_auto_map, public_key_encrypt_rgsw, rgsw_by_rgsw_inplace, rgsw_x_rgsw_scratch_rows,
29 rlwe_auto_scratch_rows, rlwe_x_rgsw_scratch_rows, secret_key_encrypt_rgsw,
30 seeded_auto_key_gen, RgswCiphertextMutRef, RgswCiphertextRef, RuntimeScratchMutRef,
31 },
32 utils::{
33 encode_x_pow_si_with_emebedding_factor, mod_exponent, puncture_p_rng, TryConvertFrom1,
34 WithLocal,
35 },
36 Encoder, Matrix, MatrixEntity, MatrixMut, RowEntity, RowMut,
37};
38
39use super::{
40 keys::{
41 ClientKey, CommonReferenceSeededCollectivePublicKeyShare,
42 CommonReferenceSeededInteractiveMultiPartyServerKeyShare,
43 CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare,
44 InteractiveMultiPartyClientKey, NonInteractiveMultiPartyClientKey,
45 SeededInteractiveMultiPartyServerKey, SeededNonInteractiveMultiPartyServerKey,
46 SeededSinglePartyServerKey, SinglePartyClientKey,
47 },
48 parameters::{BoolParameters, CiphertextModulus, DecompositionCount, DoubleDecomposerParams},
49};
50
51/// Common reference seed used for Interactive multi-party,
52///
53/// Seeds for public key shares and differents parts of server key shares are
54/// derived from common reference seed with different puncture rountines.
55///
56/// ## Punctures
57///
58/// Initial Seed:
59/// Puncture 1 -> Public key share seed
60/// Puncture 2 -> Main server key share seed
61/// Puncture 1 -> Auto keys cipertexts seed
62/// Puncture 2 -> LWE ksk seed
63#[derive(Clone, PartialEq)]
64pub struct InteractiveMultiPartyCrs<S> {
65 pub(super) seed: S,
66}
67
68impl InteractiveMultiPartyCrs<[u8; 32]> {
69 pub(super) fn random() -> Self {
70 DefaultSecureRng::with_local_mut(|rng| {
71 let mut seed = [0u8; 32];
72 rng.fill_bytes(&mut seed);
73 Self { seed }
74 })
75 }
76}
77
78impl<S: Default + Copy> InteractiveMultiPartyCrs<S> {
79 /// Seed to generate public key share
80 fn public_key_share_seed<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
81 let mut prng = Rng::new_with_seed(self.seed);
82 puncture_p_rng(&mut prng, 1)
83 }
84
85 /// Main server key share seed
86 fn key_seed<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
87 let mut prng = Rng::new_with_seed(self.seed);
88 puncture_p_rng(&mut prng, 2)
89 }
90
91 pub(super) fn auto_keys_cts_seed<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
92 let mut key_prng = Rng::new_with_seed(self.key_seed::<Rng>());
93 puncture_p_rng(&mut key_prng, 1)
94 }
95
96 pub(super) fn lwe_ksk_cts_seed_seed<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
97 let mut key_prng = Rng::new_with_seed(self.key_seed::<Rng>());
98 puncture_p_rng(&mut key_prng, 2)
99 }
100}
101
102/// Common reference seed used for non-interactive multi-party.
103///
104/// Initial Seed
105/// Puncture 1 -> Key Seed
106/// Puncture 1 -> Rgsw ciphertext seed
107/// Puncture l+1 -> Seed for zero encs and non-interactive
108/// multi-party RGSW ciphertexts of
109/// l^th LWE index.
110/// Puncture 2 -> auto keys seed
111/// Puncture 3 -> Lwe key switching key seed
112/// Puncture 2 -> user specific seed for u_j to s ksk
113/// Punture j+1 -> user j's seed
114#[derive(Clone, PartialEq)]
115pub struct NonInteractiveMultiPartyCrs<S> {
116 pub(super) seed: S,
117}
118
119impl NonInteractiveMultiPartyCrs<[u8; 32]> {
120 pub(super) fn random() -> Self {
121 DefaultSecureRng::with_local_mut(|rng| {
122 let mut seed = [0u8; 32];
123 rng.fill_bytes(&mut seed);
124 Self { seed }
125 })
126 }
127}
128
129impl<S: Default + Copy> NonInteractiveMultiPartyCrs<S> {
130 fn key_seed<R: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
131 let mut p_rng = R::new_with_seed(self.seed);
132 puncture_p_rng(&mut p_rng, 1)
133 }
134
135 pub(crate) fn ni_rgsw_cts_main_seed<R: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
136 let mut p_rng = R::new_with_seed(self.key_seed::<R>());
137 puncture_p_rng(&mut p_rng, 1)
138 }
139
140 pub(crate) fn ni_rgsw_ct_seed_for_index<R: NewWithSeed<Seed = S> + RandomFill<S>>(
141 &self,
142 lwe_index: usize,
143 ) -> S {
144 let mut p_rng = R::new_with_seed(self.ni_rgsw_cts_main_seed::<R>());
145 puncture_p_rng(&mut p_rng, lwe_index + 1)
146 }
147
148 pub(crate) fn auto_keys_cts_seed<R: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
149 let mut p_rng = R::new_with_seed(self.key_seed::<R>());
150 puncture_p_rng(&mut p_rng, 2)
151 }
152
153 pub(crate) fn lwe_ksk_cts_seed<R: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
154 let mut p_rng = R::new_with_seed(self.key_seed::<R>());
155 puncture_p_rng(&mut p_rng, 3)
156 }
157
158 fn ui_to_s_ks_seed<R: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
159 let mut p_rng = R::new_with_seed(self.seed);
160 puncture_p_rng(&mut p_rng, 2)
161 }
162
163 pub(crate) fn ui_to_s_ks_seed_for_user_i<R: NewWithSeed<Seed = S> + RandomFill<S>>(
164 &self,
165 user_i: usize,
166 ) -> S {
167 let ks_seed = self.ui_to_s_ks_seed::<R>();
168 let mut p_rng = R::new_with_seed(ks_seed);
169
170 puncture_p_rng(&mut p_rng, user_i + 1)
171 }
172}
173
174pub(crate) trait BooleanGates {
175 type Ciphertext: RowEntity;
176 type Key;
177
178 fn and_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
179 fn nand_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
180 fn or_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
181 fn nor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
182 fn xor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
183 fn xnor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key);
184 fn not_inplace(&mut self, c: &mut Self::Ciphertext);
185
186 fn and(
187 &mut self,
188 c0: &Self::Ciphertext,
189 c1: &Self::Ciphertext,
190 key: &Self::Key,
191 ) -> Self::Ciphertext;
192 fn nand(
193 &mut self,
194 c0: &Self::Ciphertext,
195 c1: &Self::Ciphertext,
196 key: &Self::Key,
197 ) -> Self::Ciphertext;
198 fn or(
199 &mut self,
200 c0: &Self::Ciphertext,
201 c1: &Self::Ciphertext,
202 key: &Self::Key,
203 ) -> Self::Ciphertext;
204 fn nor(
205 &mut self,
206 c0: &Self::Ciphertext,
207 c1: &Self::Ciphertext,
208 key: &Self::Key,
209 ) -> Self::Ciphertext;
210 fn xor(
211 &mut self,
212 c0: &Self::Ciphertext,
213 c1: &Self::Ciphertext,
214 key: &Self::Key,
215 ) -> Self::Ciphertext;
216 fn xnor(
217 &mut self,
218 c0: &Self::Ciphertext,
219 c1: &Self::Ciphertext,
220 key: &Self::Key,
221 ) -> Self::Ciphertext;
222 fn not(&mut self, c: &Self::Ciphertext) -> Self::Ciphertext;
223}
224
225struct ScratchMemory<M>
226where
227 M: Matrix,
228{
229 lwe_vector: M::R,
230 decomposition_matrix: M,
231}
232
233impl<M: MatrixEntity> ScratchMemory<M>
234where
235 M::R: RowEntity,
236{
237 fn new(parameters: &BoolParameters<M::MatElement>) -> Self {
238 // Vector to store LWE ciphertext with LWE dimesnion n
239 let lwe_vector = M::R::zeros(parameters.lwe_n().0 + 1);
240
241 // PBS perform two operations at runtime: RLWE x RGW and RLWE auto. Since the
242 // operations are performed serially same scratch space can be used for both.
243 // Hence we create scratch space that contains maximum amount of rows that
244 // suffices for RLWE x RGSW and RLWE auto
245 let decomposition_matrix = M::zeros(
246 std::cmp::max(
247 rlwe_x_rgsw_scratch_rows(parameters.rlwe_by_rgsw_decomposition_params()),
248 rlwe_auto_scratch_rows(parameters.auto_decomposition_param()),
249 ),
250 parameters.rlwe_n().0,
251 );
252
253 Self {
254 lwe_vector,
255 decomposition_matrix,
256 }
257 }
258}
259
260pub(super) trait BoolEncoding {
261 type Element;
262 fn true_el(&self) -> Self::Element;
263 fn false_el(&self) -> Self::Element;
264 fn qby4(&self) -> Self::Element;
265 fn decode(&self, m: Self::Element) -> bool;
266}
267
268impl<T> BoolEncoding for CiphertextModulus<T>
269where
270 CiphertextModulus<T>: Modulus<Element = T>,
271 T: PrimInt + NumInfo,
272{
273 type Element = T;
274
275 fn qby4(&self) -> Self::Element {
276 if self.is_native() {
277 T::one() << ((T::BITS as usize) - 2)
278 } else {
279 self.q().unwrap() >> 2
280 }
281 }
282 /// Q/8
283 fn true_el(&self) -> Self::Element {
284 if self.is_native() {
285 T::one() << ((T::BITS as usize) - 3)
286 } else {
287 self.q().unwrap() >> 3
288 }
289 }
290 /// -Q/8
291 fn false_el(&self) -> Self::Element {
292 self.largest_unsigned_value() - self.true_el() + T::one()
293 }
294 fn decode(&self, m: Self::Element) -> bool {
295 let qby8 = self.true_el();
296 let m = (((m + qby8).to_f64().unwrap() * 4.0f64) / self.q_as_f64().unwrap()).round()
297 as usize
298 % 4usize;
299
300 if m == 0 {
301 return false;
302 } else if m == 1 {
303 return true;
304 } else {
305 panic!("Incorrect bool decryption. Got m={m} but expected m to be 0 or 1")
306 }
307 }
308}
309
310impl<B> Encoder<bool, B::Element> for B
311where
312 B: BoolEncoding,
313{
314 fn encode(&self, v: bool) -> B::Element {
315 if v {
316 self.true_el()
317 } else {
318 self.false_el()
319 }
320 }
321}
322
323pub(super) struct BoolPbsInfo<M: Matrix, Ntt, RlweModOp, LweModOp> {
324 auto_decomposer: DefaultDecomposer<M::MatElement>,
325 rlwe_rgsw_decomposer: (
326 DefaultDecomposer<M::MatElement>,
327 DefaultDecomposer<M::MatElement>,
328 ),
329 lwe_decomposer: DefaultDecomposer<M::MatElement>,
330 g_k_dlog_map: Vec<usize>,
331 rlwe_nttop: Ntt,
332 rlwe_modop: RlweModOp,
333 lwe_modop: LweModOp,
334 embedding_factor: usize,
335 rlwe_qby4: M::MatElement,
336 rlwe_auto_maps: Vec<(Vec<usize>, Vec<bool>)>,
337 parameters: BoolParameters<M::MatElement>,
338}
339
340impl<M: Matrix, NttOp, RlweModOp, LweModOp> PbsInfo for BoolPbsInfo<M, NttOp, RlweModOp, LweModOp>
341where
342 M::MatElement: PrimInt
343 + WrappingSub
344 + NumInfo
345 + FromPrimitive
346 + From<bool>
347 + Display
348 + WrappingAdd
349 + Debug,
350 RlweModOp: ArithmeticOps<Element = M::MatElement> + ShoupMatrixFMA<M::R>,
351 LweModOp: ArithmeticOps<Element = M::MatElement> + VectorOps<Element = M::MatElement>,
352 NttOp: Ntt<Element = M::MatElement>,
353{
354 type M = M;
355 type Modulus = CiphertextModulus<M::MatElement>;
356 type D = DefaultDecomposer<M::MatElement>;
357 type RlweModOp = RlweModOp;
358 type LweModOp = LweModOp;
359 type NttOp = NttOp;
360 fn rlwe_auto_map(&self, k: usize) -> &(Vec<usize>, Vec<bool>) {
361 &self.rlwe_auto_maps[k]
362 }
363 fn br_q(&self) -> usize {
364 *self.parameters.br_q()
365 }
366 fn lwe_decomposer(&self) -> &Self::D {
367 &self.lwe_decomposer
368 }
369 fn rlwe_rgsw_decomposer(&self) -> &(Self::D, Self::D) {
370 &self.rlwe_rgsw_decomposer
371 }
372 fn auto_decomposer(&self) -> &Self::D {
373 &self.auto_decomposer
374 }
375 fn embedding_factor(&self) -> usize {
376 self.embedding_factor
377 }
378 fn g(&self) -> isize {
379 self.parameters.g() as isize
380 }
381 fn w(&self) -> usize {
382 self.parameters.w()
383 }
384 fn g_k_dlog_map(&self) -> &[usize] {
385 &self.g_k_dlog_map
386 }
387 fn lwe_n(&self) -> usize {
388 self.parameters.lwe_n().0
389 }
390 fn lwe_q(&self) -> &Self::Modulus {
391 self.parameters.lwe_q()
392 }
393 fn rlwe_n(&self) -> usize {
394 self.parameters.rlwe_n().0
395 }
396 fn rlwe_q(&self) -> &Self::Modulus {
397 self.parameters.rlwe_q()
398 }
399 fn modop_lweq(&self) -> &Self::LweModOp {
400 &self.lwe_modop
401 }
402 fn modop_rlweq(&self) -> &Self::RlweModOp {
403 &self.rlwe_modop
404 }
405 fn nttop_rlweq(&self) -> &Self::NttOp {
406 &self.rlwe_nttop
407 }
408}
409
410pub(crate) struct BoolEvaluator<M, Ntt, RlweModOp, LweModOp, SKey>
411where
412 M: Matrix,
413{
414 pbs_info: BoolPbsInfo<M, Ntt, RlweModOp, LweModOp>,
415 scratch_memory: ScratchMemory<M>,
416 nand_test_vec: M::R,
417 and_test_vec: M::R,
418 or_test_vec: M::R,
419 nor_test_vec: M::R,
420 xor_test_vec: M::R,
421 xnor_test_vec: M::R,
422 /// Non-interactive u_i -> s key switch decomposer
423 ni_ui_to_s_ks_decomposer: Option<DefaultDecomposer<M::MatElement>>,
424 _phantom: PhantomData<SKey>,
425}
426
427impl<M: Matrix, NttOp, RlweModOp, LweModOp, Skey>
428 BoolEvaluator<M, NttOp, RlweModOp, LweModOp, Skey>
429{
430 pub(crate) fn parameters(&self) -> &BoolParameters<M::MatElement> {
431 &self.pbs_info.parameters
432 }
433
434 pub(super) fn pbs_info(&self) -> &BoolPbsInfo<M, NttOp, RlweModOp, LweModOp> {
435 &self.pbs_info
436 }
437
438 pub(super) fn ni_ui_to_s_ks_decomposer(&self) -> &Option<DefaultDecomposer<M::MatElement>> {
439 &self.ni_ui_to_s_ks_decomposer
440 }
441}
442
443fn trim_rgsw_ct_matrix_from_rgrg_to_rlrg<
444 M: MatrixMut + MatrixEntity,
445 D: DoubleDecomposerParams<Count = DecompositionCount>,
446>(
447 rgsw_ct_in: M,
448 rgrg_params: D,
449 rlrg_params: D,
450) -> M
451where
452 M::R: RowMut,
453 M::MatElement: Copy,
454{
455 let (rgswrgsw_d_a, rgswrgsw_d_b) = (
456 rgrg_params.decomposition_count_a(),
457 rgrg_params.decomposition_count_b(),
458 );
459 let (rlrg_d_a, rlrg_d_b) = (
460 rlrg_params.decomposition_count_a(),
461 rlrg_params.decomposition_count_b(),
462 );
463 let rgsw_ct_rows_in = rgswrgsw_d_a.0 * 2 + rgswrgsw_d_b.0 * 2;
464 let rgsw_ct_rows_out = rlrg_d_a.0 * 2 + rlrg_d_b.0 * 2;
465 assert!(rgsw_ct_in.dimension().0 == rgsw_ct_rows_in);
466 assert!(rgswrgsw_d_a.0 >= rlrg_d_a.0, "RGSWxRGSW part A decomposition count {} must be >= RLWExRGSW part A decomposition count {}", rgswrgsw_d_a.0 , rlrg_d_a.0);
467 assert!(rgswrgsw_d_b.0 >= rlrg_d_b.0, "RGSWxRGSW part B decomposition count {} must be >= RLWExRGSW part B decomposition count {}", rgswrgsw_d_b.0 , rlrg_d_b.0);
468
469 let mut reduced_ct_i_out = M::zeros(rgsw_ct_rows_out, rgsw_ct_in.dimension().1);
470
471 // RLWE'(-sm) part A
472 izip!(
473 reduced_ct_i_out.iter_rows_mut().take(rlrg_d_a.0),
474 rgsw_ct_in
475 .iter_rows()
476 .skip(rgswrgsw_d_a.0 - rlrg_d_a.0)
477 .take(rlrg_d_a.0)
478 )
479 .for_each(|(to_ri, from_ri)| {
480 to_ri.as_mut().copy_from_slice(from_ri.as_ref());
481 });
482
483 // RLWE'(-sm) part B
484 izip!(
485 reduced_ct_i_out
486 .iter_rows_mut()
487 .skip(rlrg_d_a.0)
488 .take(rlrg_d_a.0),
489 rgsw_ct_in
490 .iter_rows()
491 .skip(rgswrgsw_d_a.0 + (rgswrgsw_d_a.0 - rlrg_d_a.0))
492 .take(rlrg_d_a.0)
493 )
494 .for_each(|(to_ri, from_ri)| {
495 to_ri.as_mut().copy_from_slice(from_ri.as_ref());
496 });
497
498 // RLWE'(m) Part A
499 izip!(
500 reduced_ct_i_out
501 .iter_rows_mut()
502 .skip(rlrg_d_a.0 * 2)
503 .take(rlrg_d_b.0),
504 rgsw_ct_in
505 .iter_rows()
506 .skip(rgswrgsw_d_a.0 * 2 + (rgswrgsw_d_b.0 - rlrg_d_b.0))
507 .take(rlrg_d_b.0)
508 )
509 .for_each(|(to_ri, from_ri)| {
510 to_ri.as_mut().copy_from_slice(from_ri.as_ref());
511 });
512
513 // RLWE'(m) Part B
514 izip!(
515 reduced_ct_i_out
516 .iter_rows_mut()
517 .skip(rlrg_d_a.0 * 2 + rlrg_d_b.0)
518 .take(rlrg_d_b.0),
519 rgsw_ct_in
520 .iter_rows()
521 .skip(rgswrgsw_d_a.0 * 2 + rgswrgsw_d_b.0 + (rgswrgsw_d_b.0 - rlrg_d_b.0))
522 .take(rlrg_d_b.0)
523 )
524 .for_each(|(to_ri, from_ri)| {
525 to_ri.as_mut().copy_from_slice(from_ri.as_ref());
526 });
527
528 reduced_ct_i_out
529}
530
531fn produce_rgsw_ciphertext_from_ni_rgsw<
532 M: MatrixMut + MatrixEntity,
533 D: RlweDecomposer,
534 ModOp: VectorOps<Element = M::MatElement>,
535 NttOp: Ntt<Element = M::MatElement>,
536>(
537 ni_rgsw_ct: &M,
538 aggregated_decomposed_ni_rgsw_zero_encs: &[M],
539 decomposed_neg_ais: &[M],
540 decomposer: &D,
541 parameters: &BoolParameters<M::MatElement>,
542 uj_to_s_ksk: (&M, &M),
543 rlwe_modop: &ModOp,
544 nttop: &NttOp,
545 out_eval: bool,
546) -> M
547where
548 <M as Matrix>::R: RowMut + Clone,
549{
550 let max_decomposer =
551 if decomposer.a().decomposition_count().0 > decomposer.b().decomposition_count().0 {
552 decomposer.a()
553 } else {
554 decomposer.b()
555 };
556
557 assert!(
558 ni_rgsw_ct.dimension()
559 == (
560 max_decomposer.decomposition_count().0,
561 parameters.rlwe_n().0
562 )
563 );
564 assert!(
565 aggregated_decomposed_ni_rgsw_zero_encs.len() == decomposer.a().decomposition_count().0,
566 );
567 assert!(decomposed_neg_ais.len() == decomposer.b().decomposition_count().0);
568
569 let mut rgsw_i = M::zeros(
570 decomposer.a().decomposition_count().0 * 2 + decomposer.b().decomposition_count().0 * 2,
571 parameters.rlwe_n().0,
572 );
573 let (rlwe_dash_nsm, rlwe_dash_m) =
574 rgsw_i.split_at_row_mut(decomposer.a().decomposition_count().0 * 2);
575
576 // RLWE'_{s}(-sm)
577 // Key switch `s * a_{i, l} + e` using ksk(u_j -> s) to produce RLWE(s *
578 // u_{j=user_id} * a_{i, l}).
579 //
580 // Then set RLWE_{s}(-s B^i m) = (0, u_{j=user_id} * a_{i, l} + e + B^i m) +
581 // RLWE(s * u_{j=user_id} * a_{i, l})
582 {
583 let (rlwe_dash_nsm_parta, rlwe_dash_nsm_partb) =
584 rlwe_dash_nsm.split_at_mut(decomposer.a().decomposition_count().0);
585 izip!(
586 rlwe_dash_nsm_parta.iter_mut(),
587 rlwe_dash_nsm_partb.iter_mut(),
588 ni_rgsw_ct.iter_rows().skip(
589 max_decomposer.decomposition_count().0 - decomposer.a().decomposition_count().0
590 ),
591 aggregated_decomposed_ni_rgsw_zero_encs.iter()
592 )
593 .for_each(|(rlwe_a, rlwe_b, ni_rlwe_ct, decomp_zero_enc)| {
594 // KS(s * a_{i, l} + e) = RLWE(s * u_j *
595 // a_{i, l}) using user j's Ksk
596 izip!(
597 decomp_zero_enc.iter_rows(),
598 uj_to_s_ksk.0.iter_rows(),
599 uj_to_s_ksk.1.iter_rows()
600 )
601 .for_each(|(c, pb, pa)| {
602 rlwe_modop.elwise_fma_mut(rlwe_b.as_mut(), pb.as_ref(), c.as_ref());
603 rlwe_modop.elwise_fma_mut(rlwe_a.as_mut(), pa.as_ref(), c.as_ref());
604 });
605
606 // RLWE(-s beta^i m) = (0, u_j * a_{j, l} +
607 // e + beta^i m) + RLWE(s * u_j * a_{i, l})
608 if out_eval {
609 let mut ni_rlwe_ct = ni_rlwe_ct.clone();
610 nttop.forward(ni_rlwe_ct.as_mut());
611 rlwe_modop.elwise_add_mut(rlwe_a.as_mut(), ni_rlwe_ct.as_ref());
612 } else {
613 nttop.backward(rlwe_a.as_mut());
614 nttop.backward(rlwe_b.as_mut());
615 rlwe_modop.elwise_add_mut(rlwe_a.as_mut(), ni_rlwe_ct.as_ref());
616 }
617 });
618 }
619
620 // RLWE'_{s}(m)
621 {
622 let (rlwe_dash_m_parta, rlwe_dash_partb) =
623 rlwe_dash_m.split_at_mut(decomposer.b().decomposition_count().0);
624 izip!(
625 rlwe_dash_m_parta.iter_mut(),
626 rlwe_dash_partb.iter_mut(),
627 ni_rgsw_ct.iter_rows().skip(
628 max_decomposer.decomposition_count().0 - decomposer.b().decomposition_count().0
629 ),
630 decomposed_neg_ais.iter()
631 )
632 .for_each(|(rlwe_a, rlwe_b, ni_rlwe_ct, decomp_neg_ai)| {
633 // KS(-a_{i, l}) = RLWE(u_i * -a_{i,l}) using user j's Ksk
634 izip!(
635 decomp_neg_ai.iter_rows(),
636 uj_to_s_ksk.0.iter_rows(),
637 uj_to_s_ksk.1.iter_rows()
638 )
639 .for_each(|(c, pb, pa)| {
640 rlwe_modop.elwise_fma_mut(rlwe_b.as_mut(), pb.as_ref(), c.as_ref());
641 rlwe_modop.elwise_fma_mut(rlwe_a.as_mut(), pa.as_ref(), c.as_ref());
642 });
643
644 // RLWE_{s}(beta^i m) = (u_j * a_{i, l} + e + beta^i m, 0) -
645 // RLWE(-a_{i, l} u_j)
646 if out_eval {
647 let mut ni_rlwe_ct = ni_rlwe_ct.clone();
648 nttop.forward(ni_rlwe_ct.as_mut());
649 rlwe_modop.elwise_add_mut(rlwe_b.as_mut(), ni_rlwe_ct.as_ref());
650 } else {
651 nttop.backward(rlwe_a.as_mut());
652 nttop.backward(rlwe_b.as_mut());
653 rlwe_modop.elwise_add_mut(rlwe_b.as_mut(), ni_rlwe_ct.as_ref());
654 }
655 });
656 }
657
658 rgsw_i
659}
660
661/// Assigns user with user_id segement of LWE secret indices for which they
662/// generate RGSW(X^{s[i]}) as the leader (i.e. for RLWExRGSW). If returned
663/// tuple is (start, end), user's segment is [start, end)
664pub(super) fn multi_party_user_id_lwe_segment(
665 user_id: usize,
666 total_users: usize,
667 lwe_n: usize,
668) -> (usize, usize) {
669 let per_user = (lwe_n as f64 / total_users as f64)
670 .ceil()
671 .to_usize()
672 .unwrap();
673 (
674 per_user * user_id,
675 std::cmp::min(per_user * (user_id + 1), lwe_n),
676 )
677}
678
679impl<M: Matrix, NttOp, RlweModOp, LweModOp, SKey> BoolEvaluator<M, NttOp, RlweModOp, LweModOp, SKey>
680where
681 M: MatrixEntity + MatrixMut,
682 M::MatElement: PrimInt
683 + Debug
684 + Display
685 + NumInfo
686 + FromPrimitive
687 + WrappingSub
688 + WrappingAdd
689 + SampleUniform
690 + From<bool>,
691 NttOp: Ntt<Element = M::MatElement>,
692 RlweModOp: ArithmeticOps<Element = M::MatElement>
693 + VectorOps<Element = M::MatElement>
694 + GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>
695 + ShoupMatrixFMA<M::R>,
696 LweModOp: ArithmeticOps<Element = M::MatElement>
697 + VectorOps<Element = M::MatElement>
698 + GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
699 M::R: TryConvertFrom1<[i32], CiphertextModulus<M::MatElement>> + RowEntity + Debug,
700 <M as Matrix>::R: RowMut,
701{
702 pub(super) fn new(parameters: BoolParameters<M::MatElement>) -> Self
703 where
704 RlweModOp: ModInit<M = CiphertextModulus<M::MatElement>>,
705 LweModOp: ModInit<M = CiphertextModulus<M::MatElement>>,
706 NttOp: NttInit<CiphertextModulus<M::MatElement>>,
707 {
708 //TODO(Jay): Run sanity checks for modulus values in parameters
709
710 // generates dlog map s.t. (+/-)g^{k} % q = a, for all a \in Z*_{q} and k \in
711 // [0, q/4). We store the dlog `k` at index `a`. This makes it easier to
712 // simply look up `k` at runtime as vec[a]. If a = g^{k} then dlog is
713 // stored as k. If a = -g^{k} then dlog is stored as k = q/4. This is done to
714 // differentiate sign.
715 let g = parameters.g();
716 let q = *parameters.br_q();
717 let mut g_k_dlog_map = vec![0usize; q];
718 for i in 0..q / 4 {
719 let v = mod_exponent(g as u64, i as u64, q as u64) as usize;
720 // g^i
721 g_k_dlog_map[v] = i;
722 // -(g^i)
723 g_k_dlog_map[q - v] = i + (q / 4);
724 }
725
726 let embedding_factor = (2 * parameters.rlwe_n().0) / q;
727
728 let rlwe_nttop = NttOp::new(parameters.rlwe_q(), parameters.rlwe_n().0);
729 let rlwe_modop = RlweModOp::new(*parameters.rlwe_q());
730 let lwe_modop = LweModOp::new(*parameters.lwe_q());
731
732 let q = *parameters.br_q();
733 let qby2 = q >> 1;
734 let qby8 = q >> 3;
735 // Q/8 (Q: rlwe_q)
736 let true_m_el = parameters.rlwe_q().true_el();
737 // -Q/8
738 let false_m_el = parameters.rlwe_q().false_el();
739 let (auto_map_index, auto_map_sign) = generate_auto_map(qby2, -(g as isize));
740
741 let init_test_vec = |partition_el: usize,
742 before_partition_el: M::MatElement,
743 after_partition_el: M::MatElement| {
744 let mut test_vec = M::R::zeros(qby2);
745 for i in 0..qby2 {
746 if i < partition_el {
747 test_vec.as_mut()[i] = before_partition_el;
748 } else {
749 test_vec.as_mut()[i] = after_partition_el;
750 }
751 }
752
753 // v(X) -> v(X^{-g})
754 let mut test_vec_autog = M::R::zeros(qby2);
755 izip!(
756 test_vec.as_ref().iter(),
757 auto_map_index.iter(),
758 auto_map_sign.iter()
759 )
760 .for_each(|(v, to_index, to_sign)| {
761 if !to_sign {
762 // negate
763 test_vec_autog.as_mut()[*to_index] = rlwe_modop.neg(v);
764 } else {
765 test_vec_autog.as_mut()[*to_index] = *v;
766 }
767 });
768
769 return test_vec_autog;
770 };
771
772 let nand_test_vec = init_test_vec(3 * qby8, true_m_el, false_m_el);
773 let and_test_vec = init_test_vec(3 * qby8, false_m_el, true_m_el);
774 let or_test_vec = init_test_vec(qby8, false_m_el, true_m_el);
775 let nor_test_vec = init_test_vec(qby8, true_m_el, false_m_el);
776 let xor_test_vec = init_test_vec(qby8, false_m_el, true_m_el);
777 let xnor_test_vec = init_test_vec(qby8, true_m_el, false_m_el);
778
779 // auto map indices and sign
780 // Auto maps are stored as [-g, g^{1}, g^{2}, ..., g^{w}]
781 let mut rlwe_auto_maps = vec![];
782 let ring_size = parameters.rlwe_n().0;
783 let g = parameters.g();
784 let br_q = parameters.br_q();
785 let auto_element_dlogs = parameters.auto_element_dlogs();
786 assert!(auto_element_dlogs[0] == 0);
787 for i in auto_element_dlogs.into_iter() {
788 let el = if i == 0 {
789 -(g as isize)
790 } else {
791 (g.pow(i as u32) % br_q) as isize
792 };
793 rlwe_auto_maps.push(generate_auto_map(ring_size, el))
794 }
795
796 let rlwe_qby4 = parameters.rlwe_q().qby4();
797
798 let scratch_memory = ScratchMemory::new(¶meters);
799
800 let ni_ui_to_s_ks_decomposer = if parameters.variant()
801 == &ParameterVariant::NonInteractiveMultiParty
802 {
803 Some(parameters
804 .non_interactive_ui_to_s_key_switch_decomposer::<DefaultDecomposer<M::MatElement>>())
805 } else {
806 None
807 };
808
809 let pbs_info = BoolPbsInfo {
810 auto_decomposer: parameters.auto_decomposer(),
811 lwe_decomposer: parameters.lwe_decomposer(),
812 rlwe_rgsw_decomposer: parameters.rlwe_rgsw_decomposer(),
813 g_k_dlog_map,
814 embedding_factor,
815 lwe_modop,
816 rlwe_modop,
817 rlwe_nttop,
818 rlwe_qby4,
819 rlwe_auto_maps,
820 parameters: parameters,
821 };
822
823 BoolEvaluator {
824 pbs_info,
825 scratch_memory,
826 nand_test_vec,
827 and_test_vec,
828 or_test_vec,
829 nor_test_vec,
830 xnor_test_vec,
831 xor_test_vec,
832 ni_ui_to_s_ks_decomposer,
833 _phantom: PhantomData,
834 }
835 }
836
837 pub(crate) fn client_key(
838 &self,
839 ) -> ClientKey<<DefaultSecureRng as NewWithSeed>::Seed, M::MatElement> {
840 ClientKey::new(self.parameters().clone())
841 }
842
843 pub(super) fn single_party_server_key<K: SinglePartyClientKey<Element = i32>>(
844 &self,
845 client_key: &K,
846 ) -> SeededSinglePartyServerKey<M, BoolParameters<M::MatElement>, [u8; 32]> {
847 assert_eq!(self.parameters().variant(), &ParameterVariant::SingleParty);
848
849 DefaultSecureRng::with_local_mut(|rng| {
850 let mut main_seed = [0u8; 32];
851 rng.fill_bytes(&mut main_seed);
852
853 let mut main_prng = DefaultSecureRng::new_seeded(main_seed);
854
855 let rlwe_n = self.pbs_info.parameters.rlwe_n().0;
856 let sk_rlwe = client_key.sk_rlwe();
857 let sk_lwe = client_key.sk_lwe();
858
859 // generate auto keys
860 let mut auto_keys = HashMap::new();
861 let auto_gadget = self.pbs_info.auto_decomposer.gadget_vector();
862 let g = self.pbs_info.parameters.g();
863 let br_q = self.pbs_info.parameters.br_q();
864 let auto_els = self.pbs_info.parameters.auto_element_dlogs();
865 for i in auto_els.into_iter() {
866 let g_pow = if i == 0 {
867 -(g as isize)
868 } else {
869 (g.pow(i as u32) % br_q) as isize
870 };
871 let mut gk = M::zeros(
872 self.pbs_info.auto_decomposer.decomposition_count().0,
873 rlwe_n,
874 );
875 seeded_auto_key_gen(
876 &mut gk,
877 &sk_rlwe,
878 g_pow,
879 &auto_gadget,
880 &self.pbs_info.rlwe_modop,
881 &self.pbs_info.rlwe_nttop,
882 &mut main_prng,
883 rng,
884 );
885 auto_keys.insert(i, gk);
886 }
887
888 // generate rgsw ciphertexts RGSW(si) where si is i^th LWE secret element
889 let ring_size = self.pbs_info.parameters.rlwe_n().0;
890 let rlwe_q = self.pbs_info.parameters.rlwe_q();
891 let (rlrg_d_a, rlrg_d_b) = (
892 self.pbs_info.rlwe_rgsw_decomposer.0.decomposition_count().0,
893 self.pbs_info.rlwe_rgsw_decomposer.1.decomposition_count().0,
894 );
895 let rlrg_gadget_a = self.pbs_info.rlwe_rgsw_decomposer.0.gadget_vector();
896 let rlrg_gadget_b = self.pbs_info.rlwe_rgsw_decomposer.1.gadget_vector();
897 let rgsw_cts = sk_lwe
898 .iter()
899 .map(|si| {
900 // X^{si}; assume |emebedding_factor * si| < N
901 let mut m = M::R::zeros(ring_size);
902 let si = (self.pbs_info.embedding_factor as i32) * si;
903 // dbg!(si);
904 if si < 0 {
905 // X^{-i} = X^{2N - i} = -X^{N-i}
906 m.as_mut()[ring_size - (si.abs() as usize)] = rlwe_q.neg_one();
907 } else {
908 // X^{i}
909 m.as_mut()[si.abs() as usize] = M::MatElement::one();
910 }
911
912 let mut rgsw_si = M::zeros(rlrg_d_a * 2 + rlrg_d_b, ring_size);
913 secret_key_encrypt_rgsw(
914 &mut rgsw_si,
915 m.as_ref(),
916 &rlrg_gadget_a,
917 &rlrg_gadget_b,
918 &sk_rlwe,
919 &self.pbs_info.rlwe_modop,
920 &self.pbs_info.rlwe_nttop,
921 &mut main_prng,
922 rng,
923 );
924
925 rgsw_si
926 })
927 .collect_vec();
928
929 // LWE KSK from RLWE secret s -> LWE secret z
930 let d_lwe_gadget = self.pbs_info.lwe_decomposer.gadget_vector();
931 let lwe_ksk = seeded_lwe_ksk_keygen(
932 &sk_rlwe,
933 &sk_lwe,
934 &d_lwe_gadget,
935 &self.pbs_info.lwe_modop,
936 &mut main_prng,
937 rng,
938 );
939
940 SeededSinglePartyServerKey::from_raw(
941 auto_keys,
942 rgsw_cts,
943 lwe_ksk,
944 self.pbs_info.parameters.clone(),
945 main_seed,
946 )
947 })
948 }
949
950 pub(super) fn gen_interactive_multi_party_server_key_share<
951 K: InteractiveMultiPartyClientKey<Element = i32>,
952 >(
953 &self,
954 user_id: usize,
955 total_users: usize,
956 cr_seed: &InteractiveMultiPartyCrs<[u8; 32]>,
957 collective_pk: &M,
958 client_key: &K,
959 ) -> CommonReferenceSeededInteractiveMultiPartyServerKeyShare<
960 M,
961 BoolParameters<M::MatElement>,
962 InteractiveMultiPartyCrs<[u8; 32]>,
963 > {
964 assert_eq!(self.parameters().variant(), &ParameterVariant::MultiParty);
965 assert!(user_id < total_users);
966
967 let sk_rlwe = client_key.sk_rlwe();
968 let sk_lwe = client_key.sk_lwe();
969
970 let g = self.pbs_info.parameters.g();
971 let ring_size = self.pbs_info.parameters.rlwe_n().0;
972 let rlwe_q = self.pbs_info.parameters.rlwe_q();
973 let lwe_q = self.pbs_info.parameters.lwe_q();
974
975 let rlweq_modop = &self.pbs_info.rlwe_modop;
976 let rlweq_nttop = &self.pbs_info.rlwe_nttop;
977
978 // sanity check
979 assert!(sk_rlwe.len() == ring_size);
980 assert!(sk_lwe.len() == self.pbs_info.parameters.lwe_n().0);
981
982 // auto keys
983 let auto_keys = self._common_rountine_multi_party_auto_keys_share_gen(
984 cr_seed.auto_keys_cts_seed::<DefaultSecureRng>(),
985 &sk_rlwe,
986 );
987
988 // rgsw ciphertexts of lwe secret elements
989 let (self_leader_rgsws, not_self_leader_rgsws) = DefaultSecureRng::with_local_mut(|rng| {
990 let mut self_leader_rgsw = vec![];
991 let mut not_self_leader_rgsws = vec![];
992
993 let (segment_start, segment_end) =
994 multi_party_user_id_lwe_segment(user_id, total_users, self.pbs_info().lwe_n());
995
996 // self LWE secret indices
997 {
998 // LWE secret indices for which user is the leader they need to send RGSW(m) for
999 // RLWE x RGSW multiplication
1000 let rlrg_decomposer = self.pbs_info().rlwe_rgsw_decomposer();
1001 let (rlrg_d_a, rlrg_d_b) = (
1002 rlrg_decomposer.a().decomposition_count(),
1003 rlrg_decomposer.b().decomposition_count(),
1004 );
1005 let (gadget_a, gadget_b) = (
1006 rlrg_decomposer.a().gadget_vector(),
1007 rlrg_decomposer.b().gadget_vector(),
1008 );
1009 for s_index in segment_start..segment_end {
1010 let mut out_rgsw = M::zeros(rlrg_d_a.0 * 2 + rlrg_d_b.0 * 2, ring_size);
1011 public_key_encrypt_rgsw(
1012 &mut out_rgsw,
1013 &encode_x_pow_si_with_emebedding_factor::<
1014 M::R,
1015 CiphertextModulus<M::MatElement>,
1016 >(
1017 sk_lwe[s_index],
1018 self.pbs_info().embedding_factor(),
1019 ring_size,
1020 self.pbs_info().rlwe_q(),
1021 )
1022 .as_ref(),
1023 collective_pk,
1024 &gadget_a,
1025 &gadget_b,
1026 rlweq_modop,
1027 rlweq_nttop,
1028 rng,
1029 );
1030 self_leader_rgsw.push(out_rgsw);
1031 }
1032 }
1033
1034 // not self LWE secret indices
1035 {
1036 // LWE secret indices for which user isn't the leader, they need to send RGSW(m)
1037 // for RGSW x RGSW multiplcation
1038 let rgsw_rgsw_decomposer = self
1039 .pbs_info
1040 .parameters
1041 .rgsw_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1042 let (rgrg_d_a, rgrg_d_b) = (
1043 rgsw_rgsw_decomposer.a().decomposition_count(),
1044 rgsw_rgsw_decomposer.b().decomposition_count(),
1045 );
1046 let (rgrg_gadget_a, rgrg_gadget_b) = (
1047 rgsw_rgsw_decomposer.a().gadget_vector(),
1048 rgsw_rgsw_decomposer.b().gadget_vector(),
1049 );
1050
1051 for s_index in (0..segment_start).chain(segment_end..self.parameters().lwe_n().0) {
1052 let mut out_rgsw = M::zeros(rgrg_d_a.0 * 2 + rgrg_d_b.0 * 2, ring_size);
1053 public_key_encrypt_rgsw(
1054 &mut out_rgsw,
1055 &encode_x_pow_si_with_emebedding_factor::<
1056 M::R,
1057 CiphertextModulus<M::MatElement>,
1058 >(
1059 sk_lwe[s_index],
1060 self.pbs_info().embedding_factor(),
1061 ring_size,
1062 self.pbs_info().rlwe_q(),
1063 )
1064 .as_ref(),
1065 collective_pk,
1066 &rgrg_gadget_a,
1067 &rgrg_gadget_b,
1068 rlweq_modop,
1069 rlweq_nttop,
1070 rng,
1071 );
1072
1073 not_self_leader_rgsws.push(out_rgsw);
1074 }
1075 }
1076
1077 (self_leader_rgsw, not_self_leader_rgsws)
1078 });
1079
1080 // LWE Ksk
1081 let lwe_ksk = self._common_rountine_multi_party_lwe_ksk_share_gen(
1082 cr_seed.lwe_ksk_cts_seed_seed::<DefaultSecureRng>(),
1083 &sk_rlwe,
1084 &sk_lwe,
1085 );
1086
1087 CommonReferenceSeededInteractiveMultiPartyServerKeyShare::new(
1088 self_leader_rgsws,
1089 not_self_leader_rgsws,
1090 auto_keys,
1091 lwe_ksk,
1092 cr_seed.clone(),
1093 self.pbs_info.parameters.clone(),
1094 user_id,
1095 )
1096 }
1097
1098 pub(super) fn aggregate_interactive_multi_party_server_key_shares<S>(
1099 &self,
1100 shares: &[CommonReferenceSeededInteractiveMultiPartyServerKeyShare<
1101 M,
1102 BoolParameters<M::MatElement>,
1103 InteractiveMultiPartyCrs<S>,
1104 >],
1105 ) -> SeededInteractiveMultiPartyServerKey<
1106 M,
1107 InteractiveMultiPartyCrs<S>,
1108 BoolParameters<M::MatElement>,
1109 >
1110 where
1111 S: PartialEq + Clone,
1112 M: Clone,
1113 {
1114 assert_eq!(self.parameters().variant(), &ParameterVariant::MultiParty);
1115 assert!(shares.len() > 0);
1116
1117 let total_users = shares.len();
1118
1119 let parameters = shares[0].parameters().clone();
1120 let cr_seed = shares[0].cr_seed();
1121
1122 let rlwe_n = parameters.rlwe_n().0;
1123
1124 // sanity checks
1125 shares.iter().skip(1).for_each(|s| {
1126 assert!(s.parameters() == ¶meters);
1127 assert!(s.cr_seed() == cr_seed);
1128 });
1129
1130 let rlweq_modop = &self.pbs_info.rlwe_modop;
1131 let rlweq_nttop = &self.pbs_info.rlwe_nttop;
1132
1133 // auto keys
1134 let mut auto_keys = HashMap::new();
1135 let auto_elements_dlog = parameters.auto_element_dlogs();
1136 for i in auto_elements_dlog.into_iter() {
1137 let mut key = M::zeros(parameters.auto_decomposition_count().0, rlwe_n);
1138
1139 shares.iter().for_each(|s| {
1140 let auto_key_share_i = s.auto_keys().get(&i).expect("Auto key {i} missing");
1141 assert!(
1142 auto_key_share_i.dimension()
1143 == (parameters.auto_decomposition_count().0, rlwe_n)
1144 );
1145 izip!(key.iter_rows_mut(), auto_key_share_i.iter_rows()).for_each(
1146 |(partb_out, partb_share)| {
1147 rlweq_modop.elwise_add_mut(partb_out.as_mut(), partb_share.as_ref());
1148 },
1149 );
1150 });
1151
1152 auto_keys.insert(i, key);
1153 }
1154
1155 // rgsw ciphertext (most expensive part!)
1156 let rgsw_cts = {
1157 let rgsw_x_rgsw_decomposer =
1158 parameters.rgsw_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1159 let rlwe_x_rgsw_decomposer = self.pbs_info().rlwe_rgsw_decomposer();
1160 let rgsw_x_rgsw_dimension = (
1161 rgsw_x_rgsw_decomposer.a().decomposition_count().0 * 2
1162 + rgsw_x_rgsw_decomposer.b().decomposition_count().0 * 2,
1163 rlwe_n,
1164 );
1165 let rlwe_x_rgsw_dimension = (
1166 rlwe_x_rgsw_decomposer.a().decomposition_count().0 * 2
1167 + rlwe_x_rgsw_decomposer.b().decomposition_count().0 * 2,
1168 rlwe_n,
1169 );
1170
1171 let mut rgsw_x_rgsw_scratch = M::zeros(
1172 rgsw_x_rgsw_scratch_rows(rlwe_x_rgsw_decomposer, &rgsw_x_rgsw_decomposer),
1173 rlwe_n,
1174 );
1175
1176 let shares_in_correct_order = (0..total_users)
1177 .map(|i| shares.iter().find(|s| s.user_id() == i).unwrap())
1178 .collect_vec();
1179
1180 let lwe_n = self.parameters().lwe_n().0;
1181 let (users_segments, users_segments_sizes): (Vec<(usize, usize)>, Vec<usize>) = (0
1182 ..total_users)
1183 .map(|(user_id)| {
1184 let (start_index, end_index) =
1185 multi_party_user_id_lwe_segment(user_id, total_users, lwe_n);
1186 ((start_index, end_index), end_index - start_index)
1187 })
1188 .unzip();
1189
1190 let mut rgsw_cts = Vec::with_capacity(lwe_n);
1191 users_segments
1192 .iter()
1193 .enumerate()
1194 .for_each(|(user_id, user_segment)| {
1195 let share = shares_in_correct_order[user_id];
1196 for secret_index in user_segment.0..user_segment.1 {
1197 let mut rgsw_i =
1198 share.self_leader_rgsws()[secret_index - user_segment.0].clone();
1199 // assert already exists in RGSW x RGSW rountine
1200 assert!(rgsw_i.dimension() == rlwe_x_rgsw_dimension);
1201
1202 // multiply leader's RGSW ct at `secret_index` with RGSW cts of other users
1203 // for lwe index `secret_index`
1204 (0..total_users)
1205 .filter(|i| i != &user_id)
1206 .for_each(|other_user_id| {
1207 let mut offset = 0;
1208 if other_user_id < user_id {
1209 offset = users_segments_sizes[other_user_id];
1210 }
1211
1212 let mut other_rgsw_i = shares_in_correct_order[other_user_id]
1213 .not_self_leader_rgsws()
1214 [secret_index.checked_sub(offset).unwrap()]
1215 .clone();
1216 // assert already exists in RGSW x RGSW rountine
1217 assert!(other_rgsw_i.dimension() == rgsw_x_rgsw_dimension);
1218
1219 // send to evaluation domain for RGSwxRGSW mul
1220 other_rgsw_i
1221 .iter_rows_mut()
1222 .for_each(|r| rlweq_nttop.forward(r.as_mut()));
1223
1224 rgsw_by_rgsw_inplace(
1225 &mut RgswCiphertextMutRef::new(
1226 rgsw_i.as_mut(),
1227 rlwe_x_rgsw_decomposer.a().decomposition_count().0,
1228 rlwe_x_rgsw_decomposer.b().decomposition_count().0,
1229 ),
1230 &RgswCiphertextRef::new(
1231 other_rgsw_i.as_ref(),
1232 rgsw_x_rgsw_decomposer.a().decomposition_count().0,
1233 rgsw_x_rgsw_decomposer.b().decomposition_count().0,
1234 ),
1235 rlwe_x_rgsw_decomposer,
1236 &rgsw_x_rgsw_decomposer,
1237 &mut RuntimeScratchMutRef::new(rgsw_x_rgsw_scratch.as_mut()),
1238 rlweq_nttop,
1239 rlweq_modop,
1240 );
1241 });
1242
1243 rgsw_cts.push(rgsw_i);
1244 }
1245 });
1246
1247 rgsw_cts
1248 };
1249
1250 // LWE ksks
1251 let mut lwe_ksk = M::R::zeros(rlwe_n * parameters.lwe_decomposition_count().0);
1252 let lweq_modop = &self.pbs_info.lwe_modop;
1253 shares.iter().for_each(|si| {
1254 assert!(si.lwe_ksk().as_ref().len() == rlwe_n * parameters.lwe_decomposition_count().0);
1255 lweq_modop.elwise_add_mut(lwe_ksk.as_mut(), si.lwe_ksk().as_ref())
1256 });
1257
1258 SeededInteractiveMultiPartyServerKey::new(
1259 rgsw_cts,
1260 auto_keys,
1261 lwe_ksk,
1262 cr_seed.clone(),
1263 parameters,
1264 )
1265 }
1266
1267 pub(super) fn aggregate_non_interactive_multi_party_server_key_shares(
1268 &self,
1269 cr_seed: &NonInteractiveMultiPartyCrs<[u8; 32]>,
1270 key_shares: &[CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare<
1271 M,
1272 BoolParameters<M::MatElement>,
1273 NonInteractiveMultiPartyCrs<[u8; 32]>,
1274 >],
1275 ) -> SeededNonInteractiveMultiPartyServerKey<
1276 M,
1277 NonInteractiveMultiPartyCrs<[u8; 32]>,
1278 BoolParameters<M::MatElement>,
1279 >
1280 where
1281 M: Clone + Debug,
1282 <M as Matrix>::R: RowMut + Clone,
1283 {
1284 assert_eq!(
1285 self.parameters().variant(),
1286 &ParameterVariant::NonInteractiveMultiParty
1287 );
1288
1289 let total_users = key_shares.len();
1290 let key_shares = (0..total_users)
1291 .map(|user_id| {
1292 // find share of user_id
1293 key_shares
1294 .iter()
1295 .find(|share| share.user_index() == user_id)
1296 .expect(&format!("Key Share for user_id={user_id} missing"))
1297 })
1298 .collect_vec();
1299
1300 // check parameters and cr seed are equal
1301 {
1302 key_shares.iter().for_each(|k| {
1303 assert!(k.parameters() == self.parameters());
1304 assert!(k.cr_seed() == cr_seed);
1305 });
1306 }
1307
1308 let rlwe_modop = &self.pbs_info().rlwe_modop;
1309 let nttop = &self.pbs_info().rlwe_nttop;
1310 let ring_size = self.parameters().rlwe_n().0;
1311 let rlwe_q = self.parameters().rlwe_q();
1312 let lwe_modop = self.pbs_info().modop_lweq();
1313
1314 // Generate Key switching key from u_j to s, where u_j user j's RLWE secret and
1315 // s is the ideal RLWE secret.
1316 //
1317 // User j gives [s_j * a_{i, j} + e + \beta^i u_j] where a_{i, j} is user j
1318 // specific publicly know polynomial sampled from user j's pseudo random seed
1319 // defined in the protocol.
1320 //
1321 // User k, k != j, gives [s_k * a_{i, j} + e].
1322 //
1323 // We set Ksk(u_j -> s) = [s_j * a_{i, j} + e + \beta^i u_j + \sum_{k \in P, k
1324 // != j} s_k * a_{i, j} + e]
1325 let ni_uj_to_s_decomposer = self
1326 .parameters()
1327 .non_interactive_ui_to_s_key_switch_decomposer::<DefaultDecomposer<M::MatElement>>();
1328 let mut uj_to_s_ksks = key_shares
1329 .iter()
1330 .map(|share| {
1331 let mut useri_ui_to_s_ksk = share.ui_to_s_ksk().clone();
1332 assert!(
1333 useri_ui_to_s_ksk.dimension()
1334 == (ni_uj_to_s_decomposer.decomposition_count().0, ring_size)
1335 );
1336 key_shares
1337 .iter()
1338 .filter(|x| x.user_index() != share.user_index())
1339 .for_each(|other_share| {
1340 let op2 = other_share.ui_to_s_ksk_zero_encs_for_user_i(share.user_index());
1341 assert!(
1342 op2.dimension()
1343 == (ni_uj_to_s_decomposer.decomposition_count().0, ring_size)
1344 );
1345 izip!(useri_ui_to_s_ksk.iter_rows_mut(), op2.iter_rows()).for_each(
1346 |(add_to, add_from)| {
1347 rlwe_modop.elwise_add_mut(add_to.as_mut(), add_from.as_ref())
1348 },
1349 );
1350 });
1351 useri_ui_to_s_ksk
1352 })
1353 .collect_vec();
1354
1355 let rgsw_cts = {
1356 // Send u_j -> s ksk in evaluation domain and sample corresponding a's using
1357 // user j's ksk seed to prepare for upcoming key switches
1358 uj_to_s_ksks.iter_mut().for_each(|ksk_i| {
1359 ksk_i
1360 .iter_rows_mut()
1361 .for_each(|r| nttop.forward(r.as_mut()))
1362 });
1363 let uj_to_s_ksks_part_a_eval = key_shares
1364 .iter()
1365 .map(|share| {
1366 let mut ksk_prng = DefaultSecureRng::new_seeded(
1367 cr_seed.ui_to_s_ks_seed_for_user_i::<DefaultSecureRng>(share.user_index()),
1368 );
1369 let mut ais =
1370 M::zeros(ni_uj_to_s_decomposer.decomposition_count().0, ring_size);
1371
1372 ais.iter_rows_mut().for_each(|r_ai| {
1373 RandomFillUniformInModulus::random_fill(
1374 &mut ksk_prng,
1375 rlwe_q,
1376 r_ai.as_mut(),
1377 );
1378
1379 nttop.forward(r_ai.as_mut())
1380 });
1381 ais
1382 })
1383 .collect_vec();
1384
1385 let rgsw_x_rgsw_decomposer = self
1386 .parameters()
1387 .rgsw_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1388 let rlwe_x_rgsw_decomposer = self
1389 .parameters()
1390 .rlwe_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1391
1392 let d_max = if rgsw_x_rgsw_decomposer.a().decomposition_count().0
1393 > rgsw_x_rgsw_decomposer.b().decomposition_count().0
1394 {
1395 rgsw_x_rgsw_decomposer.a().decomposition_count().0
1396 } else {
1397 rgsw_x_rgsw_decomposer.b().decomposition_count().0
1398 };
1399
1400 let mut scratch_rgsw_x_rgsw = M::zeros(
1401 rgsw_x_rgsw_scratch_rows(&rlwe_x_rgsw_decomposer, &rgsw_x_rgsw_decomposer),
1402 self.parameters().rlwe_n().0,
1403 );
1404
1405 // Recall that given u_j * a_{i, l} + e + \beta^i X^{s_j[l]} from user j
1406 //
1407 // We generate:
1408 //
1409 // - RLWE(-s \beta^i X^{s_j[l]}) = KS_{u_j -> s}(a_{i, l} * s + e) + (0 , u_j *
1410 // a_{i, l} + e + \beta^i X^{s_j[l]}), where KS_{u_j -> s}(a_{i, l} * s + e) =
1411 // RLWE_s(a_{i, l} * u_j)
1412 // - RLWE(\beta^i X^{s_j[l]}) = KS_{u_j -> s}(-a_{i,l}) + (u_j * a_{i, l} + e +
1413 // \beta^i X^{s_j[l]}, 0), where KS_{u_j -> s}(-a_{i,l}) = RLWE_s(-a_{i,l} *
1414 // u_j)
1415 //
1416 // a_{i, l} * s + e = \sum_{j \in P} a_{i, l} * s_{j} + e
1417 let user_segments = (0..total_users)
1418 .map(|user_id| {
1419 multi_party_user_id_lwe_segment(
1420 user_id,
1421 total_users,
1422 self.parameters().lwe_n().0,
1423 )
1424 })
1425 .collect_vec();
1426 // Note: Each user is assigned a contigous LWE segement and the LWE dimension is
1427 // split approximately uniformly across all users. Hence, concatenation of all
1428 // user specific lwe segments will give LWE dimension.
1429 let rgsw_cts = user_segments
1430 .into_iter()
1431 .enumerate()
1432 .flat_map(|(user_id, lwe_segment)| {
1433 (lwe_segment.0..lwe_segment.1)
1434 .into_iter()
1435 .map(|lwe_index| {
1436 // We sample d_b `-a_i`s to key switch and generate RLWE'(m). But before
1437 // we sampling we need to puncture a_prng d_max - d_b times to align
1438 // a_i's. After sampling we decompose `-a_i`s and send them to
1439 // evaluation domain for upcoming key switches.
1440 let mut a_prng = DefaultSecureRng::new_seeded(
1441 cr_seed.ni_rgsw_ct_seed_for_index::<DefaultSecureRng>(lwe_index),
1442 );
1443
1444 let mut scratch = M::R::zeros(self.parameters().rlwe_n().0);
1445 (0..d_max - rgsw_x_rgsw_decomposer.b().decomposition_count().0)
1446 .for_each(|_| {
1447 RandomFillUniformInModulus::random_fill(
1448 &mut a_prng,
1449 rlwe_q,
1450 scratch.as_mut(),
1451 );
1452 });
1453
1454 let decomp_neg_ais = (0..rgsw_x_rgsw_decomposer
1455 .b()
1456 .decomposition_count()
1457 .0)
1458 .map(|_| {
1459 RandomFillUniformInModulus::random_fill(
1460 &mut a_prng,
1461 rlwe_q,
1462 scratch.as_mut(),
1463 );
1464 rlwe_modop.elwise_neg_mut(scratch.as_mut());
1465
1466 let mut decomp_neg_ai = M::zeros(
1467 ni_uj_to_s_decomposer.decomposition_count().0,
1468 self.parameters().rlwe_n().0,
1469 );
1470 scratch.as_ref().iter().enumerate().for_each(|(index, el)| {
1471 ni_uj_to_s_decomposer
1472 .decompose_iter(el)
1473 .enumerate()
1474 .for_each(|(row_j, d_el)| {
1475 (decomp_neg_ai.as_mut()[row_j]).as_mut()[index] =
1476 d_el;
1477 });
1478 });
1479
1480 decomp_neg_ai
1481 .iter_rows_mut()
1482 .for_each(|ri| nttop.forward(ri.as_mut()));
1483
1484 decomp_neg_ai
1485 })
1486 .collect_vec();
1487
1488 // Aggregate zero encryptions to produce a_{i, l} * s + e =
1489 // \sum_{k in P} a_{i, l} * s_{k} + e where s is the ideal RLWE
1490 // secret. Aggregated a_{i, l} * s + e are key switched using
1491 // Ksk(u_j -> s) to produce RLWE_{s}(a_{i, l} * s) which are
1492 // then use to produce RLWE'(-sX^{s_{lwe}[l]}).
1493 // Hence, after aggregation we decompose a_{i, l} * s + e to
1494 // prepare for key switching
1495 let ni_rgsw_zero_encs = (0..rgsw_x_rgsw_decomposer
1496 .a()
1497 .decomposition_count()
1498 .0)
1499 .map(|i| {
1500 let mut sum = M::R::zeros(self.parameters().rlwe_n().0);
1501 key_shares.iter().for_each(|k| {
1502 let to_add_ref = k
1503 .ni_rgsw_zero_enc_for_lwe_index(lwe_index)
1504 .get_row_slice(i);
1505 assert!(to_add_ref.len() == self.parameters().rlwe_n().0);
1506 rlwe_modop.elwise_add_mut(sum.as_mut(), to_add_ref);
1507 });
1508
1509 // decompose
1510 let mut decomp_sum = M::zeros(
1511 ni_uj_to_s_decomposer.decomposition_count().0,
1512 self.parameters().rlwe_n().0,
1513 );
1514 sum.as_ref().iter().enumerate().for_each(|(index, el)| {
1515 ni_uj_to_s_decomposer
1516 .decompose_iter(el)
1517 .enumerate()
1518 .for_each(|(row_j, d_el)| {
1519 (decomp_sum.as_mut()[row_j]).as_mut()[index] = d_el;
1520 });
1521 });
1522
1523 decomp_sum
1524 .iter_rows_mut()
1525 .for_each(|r| nttop.forward(r.as_mut()));
1526
1527 decomp_sum
1528 })
1529 .collect_vec();
1530
1531 // Produce RGSW(X^{s_{j=user_id, lwe}[l]}) for the
1532 // leader, ie user's id = user_id.
1533 // Recall leader's RGSW ciphertext must be constructed
1534 // for RLWE x RGSW multiplication, and is then used
1535 // to accumulate, using RGSW x RGSW multiplication,
1536 // X^{s_{j != user_id, lwe}[l]} from other users.
1537 let mut rgsw_i = produce_rgsw_ciphertext_from_ni_rgsw(
1538 key_shares[user_id]
1539 .ni_rgsw_cts_for_self_leader_lwe_index(lwe_index),
1540 &ni_rgsw_zero_encs[rgsw_x_rgsw_decomposer
1541 .a()
1542 .decomposition_count()
1543 .0
1544 - rlwe_x_rgsw_decomposer.a().decomposition_count().0..],
1545 &decomp_neg_ais[rgsw_x_rgsw_decomposer
1546 .b()
1547 .decomposition_count()
1548 .0
1549 - rlwe_x_rgsw_decomposer.b().decomposition_count().0..],
1550 &rlwe_x_rgsw_decomposer,
1551 self.parameters(),
1552 (&uj_to_s_ksks[user_id], &uj_to_s_ksks_part_a_eval[user_id]),
1553 rlwe_modop,
1554 nttop,
1555 false,
1556 );
1557
1558 // RGSW for lwe_index of users that are not leader.
1559 //
1560 // Recall that for users that are not leader for the
1561 // lwe_index we require to produce RGSW ciphertext for
1562 // RGSW x RGSW product
1563 (0..total_users)
1564 .filter(|i| *i != user_id)
1565 .for_each(|other_user_id| {
1566 let mut other_rgsw_i = produce_rgsw_ciphertext_from_ni_rgsw(
1567 key_shares[other_user_id]
1568 .ni_rgsw_cts_for_self_not_leader_lwe_index(lwe_index),
1569 &ni_rgsw_zero_encs,
1570 &decomp_neg_ais,
1571 &rgsw_x_rgsw_decomposer,
1572 self.parameters(),
1573 (
1574 &uj_to_s_ksks[other_user_id],
1575 &uj_to_s_ksks_part_a_eval[other_user_id],
1576 ),
1577 rlwe_modop,
1578 nttop,
1579 true,
1580 );
1581
1582 rgsw_by_rgsw_inplace(
1583 &mut RgswCiphertextMutRef::new(
1584 rgsw_i.as_mut(),
1585 rlwe_x_rgsw_decomposer.a().decomposition_count().0,
1586 rlwe_x_rgsw_decomposer.b().decomposition_count().0,
1587 ),
1588 &RgswCiphertextRef::new(
1589 other_rgsw_i.as_ref(),
1590 rgsw_x_rgsw_decomposer.a().decomposition_count().0,
1591 rgsw_x_rgsw_decomposer.b().decomposition_count().0,
1592 ),
1593 &rlwe_x_rgsw_decomposer,
1594 &rgsw_x_rgsw_decomposer,
1595 &mut RuntimeScratchMutRef::new(
1596 scratch_rgsw_x_rgsw.as_mut(),
1597 ),
1598 nttop,
1599 rlwe_modop,
1600 )
1601 });
1602
1603 rgsw_i
1604 })
1605 .collect_vec()
1606 })
1607 .collect_vec();
1608
1609 // put u_j to s ksk in coefficient domain
1610 uj_to_s_ksks.iter_mut().for_each(|ksk_i| {
1611 ksk_i
1612 .iter_rows_mut()
1613 .for_each(|r| nttop.backward(r.as_mut()))
1614 });
1615
1616 rgsw_cts
1617 };
1618
1619 // auto keys
1620 let auto_keys = {
1621 let mut auto_keys = HashMap::new();
1622 let auto_elements_dlog = self.parameters().auto_element_dlogs();
1623 for i in auto_elements_dlog.into_iter() {
1624 let mut key = M::zeros(self.parameters().auto_decomposition_count().0, ring_size);
1625
1626 key_shares.iter().for_each(|s| {
1627 let auto_key_share_i =
1628 s.auto_keys_share().get(&i).expect("Auto key {i} missing");
1629 assert!(
1630 auto_key_share_i.dimension()
1631 == (self.parameters().auto_decomposition_count().0, ring_size)
1632 );
1633 izip!(key.iter_rows_mut(), auto_key_share_i.iter_rows()).for_each(
1634 |(partb_out, partb_share)| {
1635 rlwe_modop.elwise_add_mut(partb_out.as_mut(), partb_share.as_ref());
1636 },
1637 );
1638 });
1639
1640 auto_keys.insert(i, key);
1641 }
1642 auto_keys
1643 };
1644
1645 // LWE ksk
1646 let lwe_ksk = {
1647 let mut lwe_ksk =
1648 M::R::zeros(self.parameters().lwe_decomposition_count().0 * ring_size);
1649 key_shares.iter().for_each(|s| {
1650 assert!(
1651 s.lwe_ksk_share().as_ref().len()
1652 == self.parameters().lwe_decomposition_count().0 * ring_size
1653 );
1654 lwe_modop.elwise_add_mut(lwe_ksk.as_mut(), s.lwe_ksk_share().as_ref());
1655 });
1656 lwe_ksk
1657 };
1658
1659 SeededNonInteractiveMultiPartyServerKey::new(
1660 uj_to_s_ksks,
1661 rgsw_cts,
1662 auto_keys,
1663 lwe_ksk,
1664 cr_seed.clone(),
1665 self.parameters().clone(),
1666 )
1667 }
1668
1669 pub(super) fn gen_non_interactive_multi_party_key_share<
1670 K: NonInteractiveMultiPartyClientKey<Element = i32>,
1671 >(
1672 &self,
1673 cr_seed: &NonInteractiveMultiPartyCrs<[u8; 32]>,
1674 self_index: usize,
1675 total_users: usize,
1676 client_key: &K,
1677 ) -> CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare<
1678 M,
1679 BoolParameters<M::MatElement>,
1680 NonInteractiveMultiPartyCrs<[u8; 32]>,
1681 > {
1682 assert_eq!(
1683 self.parameters().variant(),
1684 &ParameterVariant::NonInteractiveMultiParty
1685 );
1686
1687 // TODO: check whether parameters support `total_users`
1688 let nttop = self.pbs_info().nttop_rlweq();
1689 let rlwe_modop = self.pbs_info().modop_rlweq();
1690 let ring_size = self.pbs_info().rlwe_n();
1691 let rlwe_q = self.parameters().rlwe_q();
1692
1693 let sk_rlwe = client_key.sk_rlwe();
1694 let sk_u_rlwe = client_key.sk_u_rlwe();
1695 let sk_lwe = client_key.sk_lwe();
1696
1697 let (ui_to_s_ksk, ksk_zero_encs_for_others) = DefaultSecureRng::with_local_mut(|rng| {
1698 // ui_to_s_ksk
1699 let non_interactive_decomposer = self
1700 .parameters()
1701 .non_interactive_ui_to_s_key_switch_decomposer::<DefaultDecomposer<M::MatElement>>(
1702 );
1703 let non_interactive_gadget_vec = non_interactive_decomposer.gadget_vector();
1704 let ui_to_s_ksk = {
1705 let mut p_rng = DefaultSecureRng::new_seeded(
1706 cr_seed.ui_to_s_ks_seed_for_user_i::<DefaultSecureRng>(self_index),
1707 );
1708
1709 non_interactive_ksk_gen::<M, _, _, _, _, _>(
1710 &sk_rlwe,
1711 &sk_u_rlwe,
1712 &non_interactive_gadget_vec,
1713 &mut p_rng,
1714 rng,
1715 nttop,
1716 rlwe_modop,
1717 )
1718 };
1719
1720 // zero encryptions for others uj_to_s ksk
1721 let all_users_except_self = (0..total_users).filter(|x| *x != self_index);
1722 let zero_encs_for_others = all_users_except_self
1723 .map(|other_user_index| {
1724 let mut p_rng = DefaultSecureRng::new_seeded(
1725 cr_seed.ui_to_s_ks_seed_for_user_i::<DefaultSecureRng>(other_user_index),
1726 );
1727 let zero_encs =
1728 non_interactive_ksk_zero_encryptions_for_other_party_i::<M, _, _, _, _, _>(
1729 &sk_rlwe,
1730 &non_interactive_gadget_vec,
1731 &mut p_rng,
1732 rng,
1733 nttop,
1734 rlwe_modop,
1735 );
1736 zero_encs
1737 })
1738 .collect_vec();
1739
1740 (ui_to_s_ksk, zero_encs_for_others)
1741 });
1742
1743 // Non-interactive RGSW cts
1744 let (ni_rgsw_zero_encs, self_leader_ni_rgsw_cts, not_self_leader_rgsw_cts) = {
1745 let rgsw_x_rgsw_decomposer = self
1746 .parameters()
1747 .rgsw_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1748 let rlwe_x_rgsw_decomposer = self
1749 .parameters()
1750 .rlwe_rgsw_decomposer::<DefaultDecomposer<M::MatElement>>();
1751
1752 // We assume that d_{a/b} for RGSW x RGSW are always < d'_{a/b} for RLWE x RGSW
1753 assert!(
1754 rlwe_x_rgsw_decomposer.a().decomposition_count().0
1755 < rgsw_x_rgsw_decomposer.a().decomposition_count().0
1756 );
1757 assert!(
1758 rlwe_x_rgsw_decomposer.b().decomposition_count().0
1759 < rgsw_x_rgsw_decomposer.b().decomposition_count().0
1760 );
1761
1762 let sj_poly_eval = {
1763 let mut s = M::R::try_convert_from(&sk_rlwe, rlwe_q);
1764 nttop.forward(s.as_mut());
1765 s
1766 };
1767
1768 let d_rgsw_a = rgsw_x_rgsw_decomposer.a().decomposition_count().0;
1769 let d_rgsw_b = rgsw_x_rgsw_decomposer.b().decomposition_count().0;
1770 let d_max = std::cmp::max(d_rgsw_a, d_rgsw_b);
1771
1772 // Zero encyptions for each LWE index. We generate d_a zero encryptions for each
1773 // LWE index using a_{i, l} with i \in {d_max - d_a , d_max) and l = lwe_index
1774 let zero_encs = {
1775 (0..self.parameters().lwe_n().0)
1776 .map(|lwe_index| {
1777 let mut p_rng = DefaultSecureRng::new_seeded(
1778 cr_seed.ni_rgsw_ct_seed_for_index::<DefaultSecureRng>(lwe_index),
1779 );
1780
1781 let mut scratch = M::R::zeros(self.parameters().rlwe_n().0);
1782
1783 // puncture seeded prng d_max - d_a times
1784 (0..(d_max - d_rgsw_a)).into_iter().for_each(|_| {
1785 RandomFillUniformInModulus::random_fill(
1786 &mut p_rng,
1787 rlwe_q,
1788 scratch.as_mut(),
1789 );
1790 });
1791
1792 let mut zero_enc = M::zeros(d_rgsw_a, self.parameters().rlwe_n().0);
1793 zero_enc.iter_rows_mut().for_each(|out| {
1794 // sample a_i
1795 RandomFillUniformInModulus::random_fill(
1796 &mut p_rng,
1797 rlwe_q,
1798 out.as_mut(),
1799 );
1800
1801 // a_i * s_j
1802 nttop.forward(out.as_mut());
1803 rlwe_modop.elwise_mul_mut(out.as_mut(), sj_poly_eval.as_ref());
1804 nttop.backward(out.as_mut());
1805
1806 // a_j * s_j + e
1807 DefaultSecureRng::with_local_mut_mut(&mut |rng| {
1808 RandomFillGaussianInModulus::random_fill(
1809 rng,
1810 rlwe_q,
1811 scratch.as_mut(),
1812 );
1813 });
1814
1815 rlwe_modop.elwise_add_mut(out.as_mut(), scratch.as_ref());
1816 });
1817
1818 zero_enc
1819 })
1820 .collect_vec()
1821 };
1822
1823 let uj_poly_eval = {
1824 let mut u = M::R::try_convert_from(&sk_u_rlwe, rlwe_q);
1825 nttop.forward(u.as_mut());
1826 u
1827 };
1828
1829 // Generate non-interactive RGSW ciphertexts a_{i, l} u_j + e + \beta X^{s_j[l]}
1830 // for i \in (0, d_max]
1831 let (self_start_index, self_end_index) = multi_party_user_id_lwe_segment(
1832 self_index,
1833 total_users,
1834 self.parameters().lwe_n().0,
1835 );
1836
1837 // For LWE indices [self_start_index, self_end_index) user generates
1838 // non-interactive RGSW cts for RLWE x RGSW product. We refer to
1839 // such indices as where user is the leader. For the rest of
1840 // the indices user generates non-interactive RGWS cts for RGSW x
1841 // RGSW multiplication. We refer to such indices as where user is
1842 // not the leader.
1843 let self_leader_ni_rgsw_cts = {
1844 let max_rlwe_x_rgsw_decomposer =
1845 if rlwe_x_rgsw_decomposer.a().decomposition_count().0
1846 > rlwe_x_rgsw_decomposer.b().decomposition_count().0
1847 {
1848 rlwe_x_rgsw_decomposer.a()
1849 } else {
1850 rlwe_x_rgsw_decomposer.b()
1851 };
1852
1853 let gadget_vec = max_rlwe_x_rgsw_decomposer.gadget_vector();
1854
1855 (self_start_index..self_end_index)
1856 .map(|lwe_index| {
1857 let mut p_rng = DefaultSecureRng::new_seeded(
1858 cr_seed.ni_rgsw_ct_seed_for_index::<DefaultSecureRng>(lwe_index),
1859 );
1860
1861 // puncture p_rng d_max - d'_max time to align with `a_{i, l}`s used to
1862 // produce RGSW cts for RGSW x RGSW
1863 let mut scratch = M::R::zeros(self.parameters().rlwe_n().0);
1864 (0..(d_max - max_rlwe_x_rgsw_decomposer.decomposition_count().0))
1865 .into_iter()
1866 .for_each(|_| {
1867 RandomFillUniformInModulus::random_fill(
1868 &mut p_rng,
1869 rlwe_q,
1870 scratch.as_mut(),
1871 );
1872 });
1873
1874 let mut ni_rgsw_cts = M::zeros(
1875 max_rlwe_x_rgsw_decomposer.decomposition_count().0,
1876 self.parameters().rlwe_n().0,
1877 );
1878
1879 // X^{s_{j, lwe}[l]}
1880 let m_poly = encode_x_pow_si_with_emebedding_factor::<M::R, _>(
1881 sk_lwe[lwe_index],
1882 self.pbs_info().embedding_factor(),
1883 self.parameters().rlwe_n().0,
1884 rlwe_q,
1885 );
1886
1887 izip!(ni_rgsw_cts.iter_rows_mut(), gadget_vec.iter()).for_each(
1888 |(out, beta)| {
1889 // sample a_i
1890 RandomFillUniformInModulus::random_fill(
1891 &mut p_rng,
1892 rlwe_q,
1893 out.as_mut(),
1894 );
1895
1896 // u_j * a_i
1897 nttop.forward(out.as_mut());
1898 rlwe_modop.elwise_mul_mut(out.as_mut(), uj_poly_eval.as_ref());
1899 nttop.backward(out.as_mut());
1900
1901 // u_j + a_i + e
1902 DefaultSecureRng::with_local_mut_mut(&mut |rng| {
1903 RandomFillGaussianInModulus::random_fill(
1904 rng,
1905 rlwe_q,
1906 scratch.as_mut(),
1907 );
1908 });
1909 rlwe_modop.elwise_add_mut(out.as_mut(), scratch.as_ref());
1910
1911 // u_j + a_i + e + beta m
1912 rlwe_modop.elwise_scalar_mul(
1913 scratch.as_mut(),
1914 m_poly.as_ref(),
1915 beta,
1916 );
1917 rlwe_modop.elwise_add_mut(out.as_mut(), scratch.as_ref());
1918 },
1919 );
1920
1921 ni_rgsw_cts
1922 })
1923 .collect_vec()
1924 };
1925
1926 let not_self_leader_rgsw_cts = {
1927 let max_rgsw_x_rgsw_decomposer =
1928 if rgsw_x_rgsw_decomposer.a().decomposition_count().0
1929 > rgsw_x_rgsw_decomposer.b().decomposition_count().0
1930 {
1931 rgsw_x_rgsw_decomposer.a()
1932 } else {
1933 rgsw_x_rgsw_decomposer.b()
1934 };
1935 let gadget_vec = max_rgsw_x_rgsw_decomposer.gadget_vector();
1936
1937 ((0..self_start_index).chain(self_end_index..self.parameters().lwe_n().0))
1938 .map(|lwe_index| {
1939 let mut p_rng = DefaultSecureRng::new_seeded(
1940 cr_seed.ni_rgsw_ct_seed_for_index::<DefaultSecureRng>(lwe_index),
1941 );
1942 let mut ni_rgsw_cts = M::zeros(
1943 max_rgsw_x_rgsw_decomposer.decomposition_count().0,
1944 self.parameters().rlwe_n().0,
1945 );
1946 let mut scratch = M::R::zeros(self.parameters().rlwe_n().0);
1947
1948 // X^{s_{j, lwe}[l]}
1949 let m_poly = encode_x_pow_si_with_emebedding_factor::<M::R, _>(
1950 sk_lwe[lwe_index],
1951 self.pbs_info().embedding_factor(),
1952 self.parameters().rlwe_n().0,
1953 rlwe_q,
1954 );
1955
1956 izip!(ni_rgsw_cts.iter_rows_mut(), gadget_vec.iter()).for_each(
1957 |(out, beta)| {
1958 // sample a_i
1959 RandomFillUniformInModulus::random_fill(
1960 &mut p_rng,
1961 rlwe_q,
1962 out.as_mut(),
1963 );
1964
1965 // u_j * a_i
1966 nttop.forward(out.as_mut());
1967 rlwe_modop.elwise_mul_mut(out.as_mut(), uj_poly_eval.as_ref());
1968 nttop.backward(out.as_mut());
1969
1970 // u_j + a_i + e
1971 DefaultSecureRng::with_local_mut_mut(&mut |rng| {
1972 RandomFillGaussianInModulus::random_fill(
1973 rng,
1974 rlwe_q,
1975 scratch.as_mut(),
1976 );
1977 });
1978 rlwe_modop.elwise_add_mut(out.as_mut(), scratch.as_ref());
1979
1980 // u_j * a_i + e + beta m
1981 rlwe_modop.elwise_scalar_mul(
1982 scratch.as_mut(),
1983 m_poly.as_ref(),
1984 beta,
1985 );
1986 rlwe_modop.elwise_add_mut(out.as_mut(), scratch.as_ref());
1987 },
1988 );
1989
1990 ni_rgsw_cts
1991 })
1992 .collect_vec()
1993 };
1994
1995 (zero_encs, self_leader_ni_rgsw_cts, not_self_leader_rgsw_cts)
1996 };
1997
1998 // Auto key share
1999 let auto_keys_share = {
2000 let auto_seed = cr_seed.auto_keys_cts_seed::<DefaultSecureRng>();
2001 self._common_rountine_multi_party_auto_keys_share_gen(auto_seed, &sk_rlwe)
2002 };
2003
2004 // Lwe Ksk share
2005 let lwe_ksk_share = {
2006 let lwe_ksk_seed = cr_seed.lwe_ksk_cts_seed::<DefaultSecureRng>();
2007 self._common_rountine_multi_party_lwe_ksk_share_gen(lwe_ksk_seed, &sk_rlwe, &sk_lwe)
2008 };
2009
2010 CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare::new(
2011 self_leader_ni_rgsw_cts,
2012 not_self_leader_rgsw_cts,
2013 ni_rgsw_zero_encs,
2014 ui_to_s_ksk,
2015 ksk_zero_encs_for_others,
2016 auto_keys_share,
2017 lwe_ksk_share,
2018 self_index,
2019 total_users,
2020 self.parameters().lwe_n().0,
2021 cr_seed.clone(),
2022 self.parameters().clone(),
2023 )
2024 }
2025
2026 fn _common_rountine_multi_party_auto_keys_share_gen(
2027 &self,
2028 auto_seed: <DefaultSecureRng as NewWithSeed>::Seed,
2029 sk_rlwe: &[i32],
2030 ) -> HashMap<usize, M> {
2031 let g = self.pbs_info.parameters.g();
2032 let ring_size = self.pbs_info.parameters.rlwe_n().0;
2033 let br_q = self.pbs_info.parameters.br_q();
2034 let rlweq_modop = &self.pbs_info.rlwe_modop;
2035 let rlweq_nttop = &self.pbs_info.rlwe_nttop;
2036
2037 DefaultSecureRng::with_local_mut(|rng| {
2038 let mut p_rng = DefaultSecureRng::new_seeded(auto_seed);
2039
2040 let mut auto_keys = HashMap::new();
2041 let auto_gadget = self.pbs_info.auto_decomposer.gadget_vector();
2042 let auto_element_dlogs = self.pbs_info.parameters.auto_element_dlogs();
2043
2044 for i in auto_element_dlogs.into_iter() {
2045 let g_pow = if i == 0 {
2046 -(g as isize)
2047 } else {
2048 (g.pow(i as u32) % br_q) as isize
2049 };
2050
2051 let mut ksk_out = M::zeros(
2052 self.pbs_info.auto_decomposer.decomposition_count().0,
2053 ring_size,
2054 );
2055 seeded_auto_key_gen(
2056 &mut ksk_out,
2057 sk_rlwe,
2058 g_pow,
2059 &auto_gadget,
2060 rlweq_modop,
2061 rlweq_nttop,
2062 &mut p_rng,
2063 rng,
2064 );
2065 auto_keys.insert(i, ksk_out);
2066 }
2067
2068 auto_keys
2069 })
2070 }
2071
2072 fn _common_rountine_multi_party_lwe_ksk_share_gen(
2073 &self,
2074 lwe_ksk_seed: <DefaultSecureRng as NewWithSeed>::Seed,
2075 sk_rlwe: &[i32],
2076 sk_lwe: &[i32],
2077 ) -> M::R {
2078 DefaultSecureRng::with_local_mut(|rng| {
2079 let mut p_rng = DefaultSecureRng::new_seeded(lwe_ksk_seed);
2080 let lwe_modop = &self.pbs_info.lwe_modop;
2081 let d_lwe_gadget_vec = self.pbs_info.lwe_decomposer.gadget_vector();
2082 seeded_lwe_ksk_keygen(
2083 sk_rlwe,
2084 sk_lwe,
2085 &d_lwe_gadget_vec,
2086 lwe_modop,
2087 &mut p_rng,
2088 rng,
2089 )
2090 })
2091 }
2092
2093 pub(super) fn multi_party_public_key_share<K: InteractiveMultiPartyClientKey<Element = i32>>(
2094 &self,
2095 cr_seed: &InteractiveMultiPartyCrs<[u8; 32]>,
2096 client_key: &K,
2097 ) -> CommonReferenceSeededCollectivePublicKeyShare<
2098 <M as Matrix>::R,
2099 [u8; 32],
2100 BoolParameters<<M as Matrix>::MatElement>,
2101 > {
2102 DefaultSecureRng::with_local_mut(|rng| {
2103 let mut share_out = M::R::zeros(self.pbs_info.parameters.rlwe_n().0);
2104 let modop = &self.pbs_info.rlwe_modop;
2105 let nttop = &self.pbs_info.rlwe_nttop;
2106 let pk_seed = cr_seed.public_key_share_seed::<DefaultSecureRng>();
2107 let mut main_prng = DefaultSecureRng::new_seeded(pk_seed);
2108 public_key_share(
2109 &mut share_out,
2110 &client_key.sk_rlwe(),
2111 modop,
2112 nttop,
2113 &mut main_prng,
2114 rng,
2115 );
2116 CommonReferenceSeededCollectivePublicKeyShare::new(
2117 share_out,
2118 pk_seed,
2119 self.pbs_info.parameters.clone(),
2120 )
2121 })
2122 }
2123
2124 pub(super) fn multi_party_decryption_share<K: InteractiveMultiPartyClientKey<Element = i32>>(
2125 &self,
2126 lwe_ct: &M::R,
2127 client_key: &K,
2128 ) -> <M as Matrix>::MatElement {
2129 assert!(lwe_ct.as_ref().len() == self.pbs_info.parameters.rlwe_n().0 + 1);
2130 let modop = &self.pbs_info.rlwe_modop;
2131 let mut neg_s =
2132 M::R::try_convert_from(&client_key.sk_rlwe(), &self.pbs_info.parameters.rlwe_q());
2133 modop.elwise_neg_mut(neg_s.as_mut());
2134
2135 let mut neg_sa = M::MatElement::zero();
2136 izip!(lwe_ct.as_ref().iter().skip(1), neg_s.as_ref().iter()).for_each(|(ai, nsi)| {
2137 neg_sa = modop.add(&neg_sa, &modop.mul(ai, nsi));
2138 });
2139
2140 let e = DefaultSecureRng::with_local_mut(|rng| {
2141 RandomGaussianElementInModulus::random(rng, self.pbs_info.parameters.rlwe_q())
2142 });
2143 let share = modop.add(&neg_sa, &e);
2144
2145 share
2146 }
2147
2148 pub(crate) fn multi_party_decrypt(&self, shares: &[M::MatElement], lwe_ct: &M::R) -> bool {
2149 let modop = &self.pbs_info.rlwe_modop;
2150 let mut sum_a = M::MatElement::zero();
2151 shares
2152 .iter()
2153 .for_each(|share_i| sum_a = modop.add(&sum_a, &share_i));
2154
2155 let encoded_m = modop.add(&lwe_ct.as_ref()[0], &sum_a);
2156 self.pbs_info.parameters.rlwe_q().decode(encoded_m)
2157 }
2158
2159 pub fn sk_encrypt<K: SinglePartyClientKey<Element = i32>>(
2160 &self,
2161 m: bool,
2162 client_key: &K,
2163 ) -> M::R {
2164 //FIXME(Jay): Figure out a way to get Q/8 form modulus
2165 let m = if m {
2166 // Q/8
2167 self.pbs_info.rlwe_q().true_el()
2168 } else {
2169 // -Q/8
2170 self.pbs_info.rlwe_q().false_el()
2171 };
2172
2173 DefaultSecureRng::with_local_mut(|rng| {
2174 encrypt_lwe(&m, &client_key.sk_rlwe(), &self.pbs_info.rlwe_modop, rng)
2175 })
2176 }
2177
2178 pub fn sk_decrypt<K: SinglePartyClientKey<Element = i32>>(
2179 &self,
2180 lwe_ct: &M::R,
2181 client_key: &K,
2182 ) -> bool {
2183 let m = decrypt_lwe(lwe_ct, &client_key.sk_rlwe(), &self.pbs_info.rlwe_modop);
2184 self.pbs_info.rlwe_q().decode(m)
2185 }
2186}
2187
2188impl<M, NttOp, RlweModOp, LweModOp, Skey> BoolEvaluator<M, NttOp, RlweModOp, LweModOp, Skey>
2189where
2190 M: MatrixMut + MatrixEntity,
2191 M::R: RowMut + RowEntity,
2192 M::MatElement: PrimInt + FromPrimitive + One + Copy + Zero + Display + WrappingSub + NumInfo,
2193 RlweModOp: VectorOps<Element = M::MatElement> + ArithmeticOps<Element = M::MatElement>,
2194 LweModOp: VectorOps<Element = M::MatElement> + ArithmeticOps<Element = M::MatElement>,
2195 NttOp: Ntt<Element = M::MatElement>,
2196{
2197 /// Returns c0 + c1 + Q/4
2198 fn _add_and_shift_lwe_cts(&self, c0: &mut M::R, c1: &M::R) {
2199 let modop = &self.pbs_info.rlwe_modop;
2200 modop.elwise_add_mut(c0.as_mut(), c1.as_ref());
2201 // +Q/4
2202 c0.as_mut()[0] = modop.add(&c0.as_ref()[0], &self.pbs_info.rlwe_qby4);
2203 }
2204
2205 /// Returns 2(c0 - c1) + Q/4
2206 fn _subtract_double_lwe_cts(&self, c0: &mut M::R, c1: &M::R) {
2207 let modop = &self.pbs_info.rlwe_modop;
2208 // c0 - c1
2209 modop.elwise_sub_mut(c0.as_mut(), c1.as_ref());
2210
2211 // double
2212 c0.as_mut().iter_mut().for_each(|v| *v = modop.add(v, v));
2213 }
2214}
2215
2216impl<M, NttOp, RlweModOp, LweModOp, Skey> BooleanGates
2217 for BoolEvaluator<M, NttOp, RlweModOp, LweModOp, Skey>
2218where
2219 M: MatrixMut + MatrixEntity,
2220 M::R: RowMut + RowEntity + Clone,
2221 M::MatElement: PrimInt
2222 + FromPrimitive
2223 + One
2224 + Copy
2225 + Zero
2226 + Display
2227 + WrappingSub
2228 + NumInfo
2229 + From<bool>
2230 + WrappingAdd
2231 + Debug,
2232 RlweModOp: VectorOps<Element = M::MatElement>
2233 + ArithmeticOps<Element = M::MatElement>
2234 + ShoupMatrixFMA<M::R>,
2235 LweModOp: VectorOps<Element = M::MatElement> + ArithmeticOps<Element = M::MatElement>,
2236 NttOp: Ntt<Element = M::MatElement>,
2237 Skey: PbsKey<AutoKey = <Skey as PbsKey>::RgswCt, LweKskKey = M>,
2238 <Skey as PbsKey>::RgswCt: WithShoupRepr<M = M>,
2239{
2240 type Ciphertext = M::R;
2241 type Key = Skey;
2242
2243 fn nand_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2244 self._add_and_shift_lwe_cts(c0, c1);
2245
2246 // PBS
2247 pbs(
2248 &self.pbs_info,
2249 &self.nand_test_vec,
2250 c0,
2251 server_key,
2252 &mut self.scratch_memory.lwe_vector,
2253 &mut self.scratch_memory.decomposition_matrix,
2254 );
2255 }
2256
2257 fn and_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2258 self._add_and_shift_lwe_cts(c0, c1);
2259
2260 // PBS
2261 pbs(
2262 &self.pbs_info,
2263 &self.and_test_vec,
2264 c0,
2265 server_key,
2266 &mut self.scratch_memory.lwe_vector,
2267 &mut self.scratch_memory.decomposition_matrix,
2268 );
2269 }
2270
2271 fn or_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2272 self._add_and_shift_lwe_cts(c0, c1);
2273
2274 // PBS
2275 pbs(
2276 &self.pbs_info,
2277 &self.or_test_vec,
2278 c0,
2279 server_key,
2280 &mut self.scratch_memory.lwe_vector,
2281 &mut self.scratch_memory.decomposition_matrix,
2282 );
2283 }
2284
2285 fn nor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2286 self._add_and_shift_lwe_cts(c0, c1);
2287
2288 // PBS
2289 pbs(
2290 &self.pbs_info,
2291 &self.nor_test_vec,
2292 c0,
2293 server_key,
2294 &mut self.scratch_memory.lwe_vector,
2295 &mut self.scratch_memory.decomposition_matrix,
2296 )
2297 }
2298
2299 fn xor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2300 self._subtract_double_lwe_cts(c0, c1);
2301
2302 // PBS
2303 pbs(
2304 &self.pbs_info,
2305 &self.xor_test_vec,
2306 c0,
2307 server_key,
2308 &mut self.scratch_memory.lwe_vector,
2309 &mut self.scratch_memory.decomposition_matrix,
2310 );
2311 }
2312
2313 fn xnor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) {
2314 self._subtract_double_lwe_cts(c0, c1);
2315
2316 // PBS
2317 pbs(
2318 &self.pbs_info,
2319 &self.xnor_test_vec,
2320 c0,
2321 server_key,
2322 &mut self.scratch_memory.lwe_vector,
2323 &mut self.scratch_memory.decomposition_matrix,
2324 );
2325 }
2326
2327 fn not_inplace(&mut self, c0: &mut M::R) {
2328 let modop = &self.pbs_info.rlwe_modop;
2329 c0.as_mut().iter_mut().for_each(|v| *v = modop.neg(v));
2330 }
2331
2332 fn and(
2333 &mut self,
2334 c0: &Self::Ciphertext,
2335 c1: &Self::Ciphertext,
2336 key: &Self::Key,
2337 ) -> Self::Ciphertext {
2338 let mut out = c0.clone();
2339 self.and_inplace(&mut out, c1, key);
2340 out
2341 }
2342
2343 fn nand(
2344 &mut self,
2345 c0: &Self::Ciphertext,
2346 c1: &Self::Ciphertext,
2347 key: &Self::Key,
2348 ) -> Self::Ciphertext {
2349 let mut out = c0.clone();
2350 self.nand_inplace(&mut out, c1, key);
2351 out
2352 }
2353
2354 fn or(
2355 &mut self,
2356 c0: &Self::Ciphertext,
2357 c1: &Self::Ciphertext,
2358 key: &Self::Key,
2359 ) -> Self::Ciphertext {
2360 let mut out = c0.clone();
2361 self.or_inplace(&mut out, c1, key);
2362 out
2363 }
2364
2365 fn nor(
2366 &mut self,
2367 c0: &Self::Ciphertext,
2368 c1: &Self::Ciphertext,
2369 key: &Self::Key,
2370 ) -> Self::Ciphertext {
2371 let mut out = c0.clone();
2372 self.nor_inplace(&mut out, c1, key);
2373 out
2374 }
2375
2376 fn xnor(
2377 &mut self,
2378 c0: &Self::Ciphertext,
2379 c1: &Self::Ciphertext,
2380 key: &Self::Key,
2381 ) -> Self::Ciphertext {
2382 let mut out = c0.clone();
2383 self.xnor_inplace(&mut out, c1, key);
2384 out
2385 }
2386
2387 fn xor(
2388 &mut self,
2389 c0: &Self::Ciphertext,
2390 c1: &Self::Ciphertext,
2391 key: &Self::Key,
2392 ) -> Self::Ciphertext {
2393 let mut out = c0.clone();
2394 self.xor_inplace(&mut out, c1, key);
2395 out
2396 }
2397
2398 fn not(&mut self, c: &Self::Ciphertext) -> Self::Ciphertext {
2399 let mut out = c.clone();
2400 self.not_inplace(&mut out);
2401 out
2402 }
2403}