use std::{ borrow::BorrowMut, cell::{OnceCell, RefCell}, clone, collections::HashMap, fmt::{Debug, Display}, iter::Once, marker::PhantomData, ops::Shr, sync::OnceLock, usize, }; use itertools::{izip, partition, Itertools}; use num_traits::{ FromPrimitive, Num, One, Pow, PrimInt, ToPrimitive, WrappingAdd, WrappingSub, Zero, }; use rand::Rng; use rand_distr::uniform::SampleUniform; use crate::{ backend::{ ArithmeticOps, GetModulus, ModInit, ModularOpsU64, Modulus, ShoupMatrixFMA, VectorOps, }, bool::parameters::ParameterVariant, decomposer::{Decomposer, DefaultDecomposer, NumInfo, RlweDecomposer}, lwe::{decrypt_lwe, encrypt_lwe, lwe_key_switch, lwe_ksk_keygen, measure_noise_lwe, LweSecret}, multi_party::{ non_interactive_ksk_gen, non_interactive_ksk_zero_encryptions_for_other_party_i, non_interactive_rgsw_ct, public_key_share, }, ntt::{self, Ntt, NttBackendU64, NttInit}, pbs::{pbs, sample_extract, PbsInfo, PbsKey, WithShoupRepr}, random::{ DefaultSecureRng, NewWithSeed, RandomFill, RandomFillGaussianInModulus, RandomFillUniformInModulus, RandomGaussianElementInModulus, }, rgsw::{ decrypt_rlwe, galois_auto, galois_key_gen, generate_auto_map, public_key_encrypt_rgsw, rgsw_by_rgsw_inplace, rlwe_by_rgsw, secret_key_encrypt_rgsw, IsTrivial, RgswCiphertext, RlweCiphertext, RlweSecret, }, utils::{ fill_random_ternary_secret_with_hamming_weight, generate_prime, mod_exponent, puncture_p_rng, Global, TryConvertFrom1, WithLocal, }, Decryptor, Encoder, Encryptor, Matrix, MatrixEntity, MatrixMut, MultiPartyDecryptor, Row, RowEntity, RowMut, Secret, }; use super::{ keys::{ ClientKey, CommonReferenceSeededCollectivePublicKeyShare, CommonReferenceSeededMultiPartyServerKeyShare, CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare, InteractiveMultiPartyClientKey, NonInteractiveMultiPartyClientKey, SeededMultiPartyServerKey, SeededNonInteractiveMultiPartyServerKey, SeededSinglePartyServerKey, ServerKeyEvaluationDomain, ShoupServerKeyEvaluationDomain, SinglePartyClientKey, }, parameters::{ BoolParameters, CiphertextModulus, DecompositionCount, DecompostionLogBase, DoubleDecomposerParams, }, }; pub struct MultiPartyCrs { pub(super) seed: S, } impl MultiPartyCrs<[u8; 32]> { pub(super) fn random() -> Self { DefaultSecureRng::with_local_mut(|rng| { let mut seed = [0u8; 32]; rng.fill_bytes(&mut seed); Self { seed } }) } } /// Common reference seed used for non-interactive multi-party. /// /// Initial Seed /// Puncture 1 -> Key Seed /// Puncture 1 -> Rgsw ciphertext seed /// Puncture 2 -> auto keys seed /// Puncture 3 -> Lwe key switching key seed /// Puncture 2 -> user specific seed for u_j to s ksk /// Punture j+1 -> user j's seed #[derive(Clone)] pub struct NonInteractiveMultiPartyCrs { pub(super) seed: S, } impl NonInteractiveMultiPartyCrs { fn key_seed + RandomFill>(&self) -> S { let mut p_rng = R::new_with_seed(self.seed); puncture_p_rng(&mut p_rng, 1) } pub(crate) fn rgsw_cts_seed + RandomFill>(&self) -> S { let key_seed = self.key_seed::(); let mut p_rng = R::new_with_seed(key_seed); puncture_p_rng(&mut p_rng, 1) } pub(crate) fn auto_keys_cts_seed + RandomFill>(&self) -> S { let key_seed = self.key_seed::(); let mut p_rng = R::new_with_seed(key_seed); puncture_p_rng(&mut p_rng, 2) } pub(crate) fn lwe_ksk_cts_seed + RandomFill>(&self) -> S { let key_seed = self.key_seed::(); let mut p_rng = R::new_with_seed(key_seed); puncture_p_rng(&mut p_rng, 3) } fn ui_to_s_ks_seed + RandomFill>(&self) -> S { let mut p_rng = R::new_with_seed(self.seed); puncture_p_rng(&mut p_rng, 2) } pub(crate) fn ui_to_s_ks_seed_for_user_i + RandomFill>( &self, user_i: usize, ) -> S { let ks_seed = self.ui_to_s_ks_seed::(); let mut p_rng = R::new_with_seed(ks_seed); puncture_p_rng(&mut p_rng, user_i + 1) } } impl MultiPartyCrs { /// Seed to generate public key share using MultiPartyCrs as the main seed. /// /// Public key seed equals the 1st seed extracted from PRNG Seeded with /// MiltiPartyCrs's seed. pub(super) fn public_key_share_seed + RandomFill>(&self) -> S { let mut prng = Rng::new_with_seed(self.seed); let mut seed = S::default(); RandomFill::::random_fill(&mut prng, &mut seed); seed } /// Seed to generate server key share using MultiPartyCrs as the main seed. /// /// Server key seed equals the 2nd seed extracted from PRNG Seeded with /// MiltiPartyCrs's seed. pub(super) fn server_key_share_seed + RandomFill>(&self) -> S { let mut prng = Rng::new_with_seed(self.seed); let mut seed = S::default(); RandomFill::::random_fill(&mut prng, &mut seed); RandomFill::::random_fill(&mut prng, &mut seed); seed } } pub(crate) trait BooleanGates { type Ciphertext: RowEntity; type Key; fn and_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn nand_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn or_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn nor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn xor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn xnor_inplace(&mut self, c0: &mut Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key); fn not_inplace(&mut self, c: &mut Self::Ciphertext); fn and( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn nand( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn or( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn nor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn xor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn xnor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext; fn not(&mut self, c: &Self::Ciphertext) -> Self::Ciphertext; } struct ScratchMemory where M: Matrix, { lwe_vector: M::R, decomposition_matrix: M, } impl ScratchMemory where M::R: RowEntity, { fn new(parameters: &BoolParameters) -> Self { // Vector to store LWE ciphertext with LWE dimesnion n let lwe_vector = M::R::zeros(parameters.lwe_n().0 + 1); // Matrix to store decomposed polynomials // Max decompistion count + space for temporary RLWE let d = std::cmp::max( parameters.auto_decomposition_count().0, std::cmp::max( parameters.rlwe_rgsw_decomposition_count().0 .0, parameters.rlwe_rgsw_decomposition_count().1 .0, ), ) + 2; let decomposition_matrix = M::zeros(d, parameters.rlwe_n().0); Self { lwe_vector, decomposition_matrix, } } } pub(super) trait BoolEncoding { type Element; fn true_el(&self) -> Self::Element; fn false_el(&self) -> Self::Element; fn qby4(&self) -> Self::Element; fn decode(&self, m: Self::Element) -> bool; } impl BoolEncoding for CiphertextModulus where CiphertextModulus: Modulus, T: PrimInt, { type Element = T; fn qby4(&self) -> Self::Element { if self.is_native() { T::one() << (CiphertextModulus::::_bits() - 2) } else { self.q().unwrap() >> 2 } } /// Q/8 fn true_el(&self) -> Self::Element { if self.is_native() { T::one() << (CiphertextModulus::::_bits() - 3) } else { self.q().unwrap() >> 3 } } /// -Q/8 fn false_el(&self) -> Self::Element { self.largest_unsigned_value() - self.true_el() + T::one() } fn decode(&self, m: Self::Element) -> bool { let qby8 = self.true_el(); let m = (((m + qby8).to_f64().unwrap() * 4.0f64) / self.q_as_f64().unwrap()).round() as usize % 4usize; if m == 0 { return false; } else if m == 1 { return true; } else { panic!("Incorrect bool decryption. Got m={m} but expected m to be 0 or 1") } } } impl Encoder for B where B: BoolEncoding, { fn encode(&self, v: bool) -> B::Element { if v { self.true_el() } else { self.false_el() } } } pub(super) struct BoolPbsInfo { auto_decomposer: DefaultDecomposer, rlwe_rgsw_decomposer: ( DefaultDecomposer, DefaultDecomposer, ), lwe_decomposer: DefaultDecomposer, g_k_dlog_map: Vec, rlwe_nttop: Ntt, rlwe_modop: RlweModOp, lwe_modop: LweModOp, embedding_factor: usize, rlwe_qby4: M::MatElement, rlwe_auto_maps: Vec<(Vec, Vec)>, parameters: BoolParameters, } impl PbsInfo for BoolPbsInfo where M::MatElement: PrimInt + WrappingSub + NumInfo + FromPrimitive + From + Display + WrappingAdd, RlweModOp: ArithmeticOps + ShoupMatrixFMA, LweModOp: ArithmeticOps + VectorOps, NttOp: Ntt, { type M = M; type Modulus = CiphertextModulus; type D = DefaultDecomposer; type RlweModOp = RlweModOp; type LweModOp = LweModOp; type NttOp = NttOp; fn rlwe_auto_map(&self, k: usize) -> &(Vec, Vec) { &self.rlwe_auto_maps[k] } fn br_q(&self) -> usize { *self.parameters.br_q() } fn lwe_decomposer(&self) -> &Self::D { &self.lwe_decomposer } fn rlwe_rgsw_decomposer(&self) -> &(Self::D, Self::D) { &self.rlwe_rgsw_decomposer } fn auto_decomposer(&self) -> &Self::D { &self.auto_decomposer } fn embedding_factor(&self) -> usize { self.embedding_factor } fn g(&self) -> isize { self.parameters.g() as isize } fn w(&self) -> usize { self.parameters.w() } fn g_k_dlog_map(&self) -> &[usize] { &self.g_k_dlog_map } fn lwe_n(&self) -> usize { self.parameters.lwe_n().0 } fn lwe_q(&self) -> &Self::Modulus { self.parameters.lwe_q() } fn rlwe_n(&self) -> usize { self.parameters.rlwe_n().0 } fn rlwe_q(&self) -> &Self::Modulus { self.parameters.rlwe_q() } fn modop_lweq(&self) -> &Self::LweModOp { &self.lwe_modop } fn modop_rlweq(&self) -> &Self::RlweModOp { &self.rlwe_modop } fn nttop_rlweq(&self) -> &Self::NttOp { &self.rlwe_nttop } } pub(crate) struct BoolEvaluator where M: Matrix, { pbs_info: BoolPbsInfo, scratch_memory: ScratchMemory, nand_test_vec: M::R, and_test_vec: M::R, or_test_vec: M::R, nor_test_vec: M::R, xor_test_vec: M::R, xnor_test_vec: M::R, /// Non-interactive u_i -> s key switch decomposer ni_ui_to_s_ks_decomposer: Option>, _phantom: PhantomData, } impl BoolEvaluator { pub(crate) fn parameters(&self) -> &BoolParameters { &self.pbs_info.parameters } pub(super) fn pbs_info(&self) -> &BoolPbsInfo { &self.pbs_info } pub(super) fn ni_ui_to_s_ks_decomposer(&self) -> &Option> { &self.ni_ui_to_s_ks_decomposer } } fn trim_rgsw_ct_matrix_from_rgrg_to_rlrg< M: MatrixMut + MatrixEntity, D: DoubleDecomposerParams, >( rgsw_ct_in: M, rgrg_params: D, rlrg_params: D, ) -> M where M::R: RowMut, M::MatElement: Copy, { let (rgswrgsw_d_a, rgswrgsw_d_b) = ( rgrg_params.decomposition_count_a(), rgrg_params.decomposition_count_b(), ); let (rlrg_d_a, rlrg_d_b) = ( rlrg_params.decomposition_count_a(), rlrg_params.decomposition_count_b(), ); let rgsw_ct_rows_in = rgswrgsw_d_a.0 * 2 + rgswrgsw_d_b.0 * 2; let rgsw_ct_rows_out = rlrg_d_a.0 * 2 + rlrg_d_b.0 * 2; assert!(rgsw_ct_in.dimension().0 == rgsw_ct_rows_in); 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); 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); let mut reduced_ct_i_out = M::zeros(rgsw_ct_rows_out, rgsw_ct_in.dimension().1); // RLWE'(-sm) part A izip!( reduced_ct_i_out.iter_rows_mut().take(rlrg_d_a.0), rgsw_ct_in .iter_rows() .skip(rgswrgsw_d_a.0 - rlrg_d_a.0) .take(rlrg_d_a.0) ) .for_each(|(to_ri, from_ri)| { to_ri.as_mut().copy_from_slice(from_ri.as_ref()); }); // RLWE'(-sm) part B izip!( reduced_ct_i_out .iter_rows_mut() .skip(rlrg_d_a.0) .take(rlrg_d_a.0), rgsw_ct_in .iter_rows() .skip(rgswrgsw_d_a.0 + (rgswrgsw_d_a.0 - rlrg_d_a.0)) .take(rlrg_d_a.0) ) .for_each(|(to_ri, from_ri)| { to_ri.as_mut().copy_from_slice(from_ri.as_ref()); }); // RLWE'(m) Part A izip!( reduced_ct_i_out .iter_rows_mut() .skip(rlrg_d_a.0 * 2) .take(rlrg_d_b.0), rgsw_ct_in .iter_rows() .skip(rgswrgsw_d_a.0 * 2 + (rgswrgsw_d_b.0 - rlrg_d_b.0)) .take(rlrg_d_b.0) ) .for_each(|(to_ri, from_ri)| { to_ri.as_mut().copy_from_slice(from_ri.as_ref()); }); // RLWE'(m) Part B izip!( reduced_ct_i_out .iter_rows_mut() .skip(rlrg_d_a.0 * 2 + rlrg_d_b.0) .take(rlrg_d_b.0), rgsw_ct_in .iter_rows() .skip(rgswrgsw_d_a.0 * 2 + rgswrgsw_d_b.0 + (rgswrgsw_d_b.0 - rlrg_d_b.0)) .take(rlrg_d_b.0) ) .for_each(|(to_ri, from_ri)| { to_ri.as_mut().copy_from_slice(from_ri.as_ref()); }); reduced_ct_i_out } impl BoolEvaluator where M: MatrixEntity + MatrixMut, M::MatElement: PrimInt + Debug + Display + NumInfo + FromPrimitive + WrappingSub + WrappingAdd + SampleUniform + From, NttOp: Ntt, RlweModOp: ArithmeticOps + VectorOps + GetModulus> + ShoupMatrixFMA, LweModOp: ArithmeticOps + VectorOps + GetModulus>, M::R: TryConvertFrom1<[i32], CiphertextModulus> + RowEntity + Debug, ::R: RowMut, { pub(super) fn new(parameters: BoolParameters) -> Self where RlweModOp: ModInit>, LweModOp: ModInit>, NttOp: NttInit>, { //TODO(Jay): Run sanity checks for modulus values in parameters // generates dlog map s.t. (+/-)g^{k} % q = a, for all a \in Z*_{q} and k \in // [0, q/4). We store the dlog `k` at index `a`. This makes it easier to // simply look up `k` at runtime as vec[a]. If a = g^{k} then dlog is // stored as k. If a = -g^{k} then dlog is stored as k = q/4. This is done to // differentiate sign. let g = parameters.g(); let q = *parameters.br_q(); let mut g_k_dlog_map = vec![0usize; q]; for i in 0..q / 4 { let v = mod_exponent(g as u64, i as u64, q as u64) as usize; // g^i g_k_dlog_map[v] = i; // -(g^i) g_k_dlog_map[q - v] = i + (q / 4); } let embedding_factor = (2 * parameters.rlwe_n().0) / q; let rlwe_nttop = NttOp::new(parameters.rlwe_q(), parameters.rlwe_n().0); let rlwe_modop = RlweModOp::new(*parameters.rlwe_q()); let lwe_modop = LweModOp::new(*parameters.lwe_q()); let q = *parameters.br_q(); let qby2 = q >> 1; let qby8 = q >> 3; // Q/8 (Q: rlwe_q) let true_m_el = parameters.rlwe_q().true_el(); // -Q/8 let false_m_el = parameters.rlwe_q().false_el(); let (auto_map_index, auto_map_sign) = generate_auto_map(qby2, -(g as isize)); let init_test_vec = |partition_el: usize, before_partition_el: M::MatElement, after_partition_el: M::MatElement| { let mut test_vec = M::R::zeros(qby2); for i in 0..qby2 { if i < partition_el { test_vec.as_mut()[i] = before_partition_el; } else { test_vec.as_mut()[i] = after_partition_el; } } // v(X) -> v(X^{-g}) let mut test_vec_autog = M::R::zeros(qby2); izip!( test_vec.as_ref().iter(), auto_map_index.iter(), auto_map_sign.iter() ) .for_each(|(v, to_index, to_sign)| { if !to_sign { // negate test_vec_autog.as_mut()[*to_index] = rlwe_modop.neg(v); } else { test_vec_autog.as_mut()[*to_index] = *v; } }); return test_vec_autog; }; let nand_test_vec = init_test_vec(3 * qby8, true_m_el, false_m_el); let and_test_vec = init_test_vec(3 * qby8, false_m_el, true_m_el); let or_test_vec = init_test_vec(qby8, false_m_el, true_m_el); let nor_test_vec = init_test_vec(qby8, true_m_el, false_m_el); let xor_test_vec = init_test_vec(qby8, false_m_el, true_m_el); let xnor_test_vec = init_test_vec(qby8, true_m_el, false_m_el); // auto map indices and sign // Auto maps are stored as [-g, g^{1}, g^{2}, ..., g^{w}] let mut rlwe_auto_maps = vec![]; let ring_size = parameters.rlwe_n().0; let g = parameters.g(); let br_q = parameters.br_q(); let auto_element_dlogs = parameters.auto_element_dlogs(); assert!(auto_element_dlogs[0] == 0); for i in auto_element_dlogs.into_iter() { let el = if i == 0 { -(g as isize) } else { (g.pow(i as u32) % br_q) as isize }; rlwe_auto_maps.push(generate_auto_map(ring_size, el)) } let rlwe_qby4 = parameters.rlwe_q().qby4(); let scratch_memory = ScratchMemory::new(¶meters); let ni_ui_to_s_ks_decomposer = if parameters.variant() == &ParameterVariant::NonInteractiveMultiParty { Some(parameters .non_interactive_ui_to_s_key_switch_decomposer::>()) } else { None }; let pbs_info = BoolPbsInfo { auto_decomposer: parameters.auto_decomposer(), lwe_decomposer: parameters.lwe_decomposer(), rlwe_rgsw_decomposer: parameters.rlwe_rgsw_decomposer(), g_k_dlog_map, embedding_factor, lwe_modop, rlwe_modop, rlwe_nttop, rlwe_qby4, rlwe_auto_maps, parameters: parameters, }; BoolEvaluator { pbs_info, scratch_memory, nand_test_vec, and_test_vec, or_test_vec, nor_test_vec, xnor_test_vec, xor_test_vec, ni_ui_to_s_ks_decomposer, _phantom: PhantomData, } } pub(crate) fn client_key( &self, ) -> ClientKey<::Seed, M::MatElement> { ClientKey::new(self.parameters().clone()) } pub(super) fn single_party_server_key>( &self, client_key: &K, ) -> SeededSinglePartyServerKey, [u8; 32]> { assert_eq!(self.parameters().variant(), &ParameterVariant::SingleParty); DefaultSecureRng::with_local_mut(|rng| { let mut main_seed = [0u8; 32]; rng.fill_bytes(&mut main_seed); let mut main_prng = DefaultSecureRng::new_seeded(main_seed); let rlwe_n = self.pbs_info.parameters.rlwe_n().0; let sk_rlwe = client_key.sk_rlwe(); let sk_lwe = client_key.sk_lwe(); // generate auto keys let mut auto_keys = HashMap::new(); let auto_gadget = self.pbs_info.auto_decomposer.gadget_vector(); let g = self.pbs_info.parameters.g(); let br_q = self.pbs_info.parameters.br_q(); let auto_els = self.pbs_info.parameters.auto_element_dlogs(); for i in auto_els.into_iter() { let g_pow = if i == 0 { -(g as isize) } else { (g.pow(i as u32) % br_q) as isize }; let mut gk = M::zeros(self.pbs_info.auto_decomposer.decomposition_count(), rlwe_n); galois_key_gen( &mut gk, &sk_rlwe, g_pow, &auto_gadget, &self.pbs_info.rlwe_modop, &self.pbs_info.rlwe_nttop, &mut main_prng, rng, ); auto_keys.insert(i, gk); } // generate rgsw ciphertexts RGSW(si) where si is i^th LWE secret element let ring_size = self.pbs_info.parameters.rlwe_n().0; let rlwe_q = self.pbs_info.parameters.rlwe_q(); let (rlrg_d_a, rlrg_d_b) = ( self.pbs_info.rlwe_rgsw_decomposer.0.decomposition_count(), self.pbs_info.rlwe_rgsw_decomposer.1.decomposition_count(), ); let rlrg_gadget_a = self.pbs_info.rlwe_rgsw_decomposer.0.gadget_vector(); let rlrg_gadget_b = self.pbs_info.rlwe_rgsw_decomposer.1.gadget_vector(); let rgsw_cts = sk_lwe .iter() .map(|si| { // X^{si}; assume |emebedding_factor * si| < N let mut m = M::R::zeros(ring_size); let si = (self.pbs_info.embedding_factor as i32) * si; // dbg!(si); if si < 0 { // X^{-i} = X^{2N - i} = -X^{N-i} m.as_mut()[ring_size - (si.abs() as usize)] = rlwe_q.neg_one(); } else { // X^{i} m.as_mut()[si.abs() as usize] = M::MatElement::one(); } let mut rgsw_si = M::zeros(rlrg_d_a * 2 + rlrg_d_b, ring_size); secret_key_encrypt_rgsw( &mut rgsw_si, m.as_ref(), &rlrg_gadget_a, &rlrg_gadget_b, &sk_rlwe, &self.pbs_info.rlwe_modop, &self.pbs_info.rlwe_nttop, &mut main_prng, rng, ); rgsw_si }) .collect_vec(); // LWE KSK from RLWE secret s -> LWE secret z let d_lwe_gadget = self.pbs_info.lwe_decomposer.gadget_vector(); let mut lwe_ksk = M::R::zeros(self.pbs_info.lwe_decomposer.decomposition_count() * ring_size); lwe_ksk_keygen( &sk_rlwe, &sk_lwe, &mut lwe_ksk, &d_lwe_gadget, &self.pbs_info.lwe_modop, &mut main_prng, rng, ); SeededSinglePartyServerKey::from_raw( auto_keys, rgsw_cts, lwe_ksk, self.pbs_info.parameters.clone(), main_seed, ) }) } pub(super) fn multi_party_server_key_share>( &self, cr_seed: [u8; 32], collective_pk: &M, client_key: &K, ) -> CommonReferenceSeededMultiPartyServerKeyShare, [u8; 32]> { assert_eq!(self.parameters().variant(), &ParameterVariant::MultiParty); DefaultSecureRng::with_local_mut(|rng| { let mut main_prng = DefaultSecureRng::new_seeded(cr_seed); let sk_rlwe = client_key.sk_rlwe(); let sk_lwe = client_key.sk_lwe(); let g = self.pbs_info.parameters.g(); let ring_size = self.pbs_info.parameters.rlwe_n().0; let rlwe_q = self.pbs_info.parameters.rlwe_q(); let lwe_q = self.pbs_info.parameters.lwe_q(); let rlweq_modop = &self.pbs_info.rlwe_modop; let rlweq_nttop = &self.pbs_info.rlwe_nttop; // sanity check assert!(sk_rlwe.len() == ring_size); assert!(sk_lwe.len() == self.pbs_info.parameters.lwe_n().0); // auto keys let mut auto_keys = HashMap::new(); let auto_gadget = self.pbs_info.auto_decomposer.gadget_vector(); let auto_element_dlogs = self.pbs_info.parameters.auto_element_dlogs(); let br_q = self.pbs_info.parameters.br_q(); for i in auto_element_dlogs.into_iter() { let g_pow = if i == 0 { -(g as isize) } else { (g.pow(i as u32) % br_q) as isize }; let mut ksk_out = M::zeros( self.pbs_info.auto_decomposer.decomposition_count(), ring_size, ); galois_key_gen( &mut ksk_out, &sk_rlwe, g_pow, &auto_gadget, rlweq_modop, rlweq_nttop, &mut main_prng, rng, ); auto_keys.insert(i, ksk_out); } // rgsw ciphertexts of lwe secret elements let rgsw_rgsw_decomposer = self .pbs_info .parameters .rgsw_rgsw_decomposer::>(); let (rgrg_d_a, rgrg_d_b) = ( rgsw_rgsw_decomposer.0.decomposition_count(), rgsw_rgsw_decomposer.1.decomposition_count(), ); let (rgrg_gadget_a, rgrg_gadget_b) = ( rgsw_rgsw_decomposer.0.gadget_vector(), rgsw_rgsw_decomposer.1.gadget_vector(), ); let rgsw_cts = sk_lwe .iter() .map(|si| { let mut m = M::R::zeros(ring_size); //TODO(Jay): It will be nice to have a function that returns polynomial // (monomial infact!) corresponding to secret element embedded in ring X^{2N+1}. // Save lots of mistakes where one forgest to emebed si in bigger ring. let si = *si * (self.pbs_info.embedding_factor as i32); if si < 0 { // X^{-si} = X^{2N-si} = -X^{N-si}, assuming abs(si) < N // (which it is given si is secret element) m.as_mut()[ring_size - (si.abs() as usize)] = rlwe_q.neg_one(); } else { m.as_mut()[si as usize] = M::MatElement::one(); } // public key RGSW encryption has no part that can be seeded, unlike secret key // RGSW encryption where RLWE'_A(m) is seeded let mut out_rgsw = M::zeros(rgrg_d_a * 2 + rgrg_d_b * 2, ring_size); public_key_encrypt_rgsw( &mut out_rgsw, &m.as_ref(), collective_pk, &rgrg_gadget_a, &rgrg_gadget_b, rlweq_modop, rlweq_nttop, rng, ); out_rgsw }) .collect_vec(); // LWE ksk let mut lwe_ksk = M::R::zeros(self.pbs_info.lwe_decomposer.decomposition_count() * ring_size); let lwe_modop = &self.pbs_info.lwe_modop; let d_lwe_gadget_vec = self.pbs_info.lwe_decomposer.gadget_vector(); lwe_ksk_keygen( &sk_rlwe, &sk_lwe, &mut lwe_ksk, &d_lwe_gadget_vec, lwe_modop, &mut main_prng, rng, ); CommonReferenceSeededMultiPartyServerKeyShare::new( rgsw_cts, auto_keys, lwe_ksk, cr_seed, self.pbs_info.parameters.clone(), ) }) } pub(super) fn aggregate_non_interactive_multi_party_key_share( &self, cr_seed: &NonInteractiveMultiPartyCrs<[u8; 32]>, total_users: usize, key_shares: &[CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare< M, NonInteractiveMultiPartyCrs<[u8; 32]>, >], ) -> SeededNonInteractiveMultiPartyServerKey< M, NonInteractiveMultiPartyCrs<[u8; 32]>, BoolParameters, > where M: Clone + Debug, { assert_eq!( self.parameters().variant(), &ParameterVariant::NonInteractiveMultiParty ); // sanity checks let key_order = { let existing_key_order = key_shares.iter().map(|s| s.user_index()).collect_vec(); // record the order s.t. key_order[i] stores the position of i^th // users key share in existing order let mut key_order = Vec::with_capacity(existing_key_order.len()); (0..total_users).for_each(|i| { // find i let index = existing_key_order .iter() .position(|x| x == &i) .expect(&format!("Missing user {i}'s key!")); key_order.push(index); }); key_order }; let rlwe_modop = &self.pbs_info().rlwe_modop; let nttop = &self.pbs_info().rlwe_nttop; let ring_size = self.parameters().rlwe_n().0; let rlwe_q = self.parameters().rlwe_q(); let lwe_modop = self.pbs_info().modop_lweq(); // genrate key switching key from u_i to s let ui_to_s_ksk_decomposition_count = self .parameters() .non_interactive_ui_to_s_key_switch_decomposition_count(); let mut ui_to_s_ksks = key_shares .iter() .map(|share| { let mut useri_ui_to_s_ksk = share.ui_to_s_ksk().clone(); assert!( useri_ui_to_s_ksk.dimension() == (ui_to_s_ksk_decomposition_count.0, ring_size) ); key_shares .iter() .filter(|x| x.user_index() != share.user_index()) .for_each(|(other_share)| { let op2 = other_share.ui_to_s_ksk_zero_encs_for_user_i(share.user_index()); assert!(op2.dimension() == (ui_to_s_ksk_decomposition_count.0, ring_size)); izip!(useri_ui_to_s_ksk.iter_rows_mut(), op2.iter_rows()).for_each( |(add_to, add_from)| { rlwe_modop.elwise_add_mut(add_to.as_mut(), add_from.as_ref()) }, ); }); useri_ui_to_s_ksk }) .collect_vec(); let rgsw_cts = { let mut rgsw_prng = DefaultSecureRng::new_seeded(cr_seed.rgsw_cts_seed::()); let rgsw_by_rgsw_decomposer = self .parameters() .rgsw_rgsw_decomposer::>(); // Generate RGSW Cts let rgsw_cts_all_users_eval = { // temporarily put ui_to_s in evaluation domain and sample a_i's for u_i to s // ksk for upcomong key switches ui_to_s_ksks.iter_mut().for_each(|ksk_i| { ksk_i .iter_rows_mut() .for_each(|r| nttop.forward(r.as_mut())) }); let ui_to_s_ksks_part_a_eval = key_shares .iter() .map(|share| { let mut ksk_prng = DefaultSecureRng::new_seeded( cr_seed .ui_to_s_ks_seed_for_user_i::(share.user_index()), ); let mut ais = M::zeros(ui_to_s_ksk_decomposition_count.0, ring_size); ais.iter_rows_mut().for_each(|r_ai| { RandomFillUniformInModulus::random_fill( &mut ksk_prng, rlwe_q, r_ai.as_mut(), ); nttop.forward(r_ai.as_mut()) }); ais }) .collect_vec(); let max_rgrg_deocmposer = if rgsw_by_rgsw_decomposer.a().decomposition_count() > rgsw_by_rgsw_decomposer.b().decomposition_count() { rgsw_by_rgsw_decomposer.a() } else { rgsw_by_rgsw_decomposer.b() }; let ui_to_s_ksk_decomposer = self .parameters() .non_interactive_ui_to_s_key_switch_decomposer::>( ); // Generate a_i*s + E = \sum_{j \in P} a_i*s_j + e for all rlwes in each // non-interactive rgsws. Then decompose and put decompositions in evaluation // for u_i -> s key switch. let decomp_ni_rgsws_part_1_acc = { let mut tmp_space = M::R::zeros(ring_size); (0..self.parameters().lwe_n().0) .into_iter() .map(|lwe_index| { (0..max_rgrg_deocmposer.decomposition_count()) .into_iter() .map(|d_index| { let mut sum = M::zeros( ui_to_s_ksk_decomposer.decomposition_count(), ring_size, ); // set temp_space to all zeros tmp_space.as_mut().fill(M::MatElement::zero()); // a_i*s + E key_shares.iter().for_each(|s| { rlwe_modop.elwise_add_mut( tmp_space.as_mut(), s.ni_rgsw_cts().1[lwe_index].get_row_slice(d_index), ); }); tmp_space.as_ref().iter().enumerate().for_each(|(ri, el)| { ui_to_s_ksk_decomposer .decompose_iter(el) .enumerate() .for_each(|(row_j, d_el)| { (sum.as_mut()[row_j]).as_mut()[ri] = d_el; }); }); sum.iter_rows_mut().for_each(|r| nttop.forward(r.as_mut())); sum }) .collect_vec() }) .collect_vec() }; // Sample a_i's are used to generate non-interactive rgsw cts for all lwe // indices. Since a_i are just needed for key switches , decompose them // and put them in evaluation domain // Decomposition count used for RGSW ct in non-interactive key share gen equals // max of A and B decomposition required in RGSWxRGSW. This is because same // polynomials are used to generate RLWE'(m) and RLWE'(-sm) let decomp_ni_rgsw_neg_ais = { let mut tmp_space = M::R::zeros(ring_size); (0..self.parameters().lwe_n().0) .into_iter() .map(|_| { // FIXME(Jay): well well, ais are only required for key switching to // generate RLWE'(m) and RLWE'(m) itself // requires RLWE(\beta^i m) for i \in RGSWxRGSW // part B decomposition count. However, we still need to puncture prng // for ais corresponding to ignored limbs. // Probably it will be nice idea to // avoid decomposition after punturing for a_i's corresponding to // ignored limbs. Moreover, note that, for // RGSWxRGSW often times decompostion count for part A // > part B. Hence, it's very likely that we are doing // unecesary decompositions for ignored limbs all the time. (0..max_rgrg_deocmposer.decomposition_count()) .map(|_| { RandomFillUniformInModulus::random_fill( &mut rgsw_prng, rlwe_q, tmp_space.as_mut(), ); // negate rlwe_modop.elwise_neg_mut(tmp_space.as_mut()); // decomposer a_i for ui -> s key switch let mut decomp_neg_ai = M::zeros( ui_to_s_ksk_decomposer.decomposition_count(), ring_size, ); tmp_space.as_ref().iter().enumerate().for_each( |(index, el)| { ui_to_s_ksk_decomposer .decompose_iter(el) .enumerate() .for_each(|(row_j, d_el)| { (decomp_neg_ai.as_mut()[row_j]).as_mut() [index] = d_el; }); }, ); // put in evaluation domain decomp_neg_ai .iter_rows_mut() .for_each(|r| nttop.forward(r.as_mut())); decomp_neg_ai }) .collect_vec() }) .collect_vec() }; // genrate RGSW cts let rgsw_cts_all_users_eval = izip!( key_shares.iter(), ui_to_s_ksks.iter(), ui_to_s_ksks_part_a_eval.iter() ) .map( |(share, user_uitos_ksk_partb_eval, user_uitos_ksk_parta_eval)| { // RGSW_s(X^{s[i]}) let rgsw_cts_user_i_eval = izip!( share.ni_rgsw_cts().0.iter(), decomp_ni_rgsw_neg_ais.iter(), decomp_ni_rgsws_part_1_acc.iter() ) .map( |( m_encs_under_ui, decomposed_rgsw_i_neg_ais, decomposed_acc_rgsw_part1, )| { let d_a = rgsw_by_rgsw_decomposer.a().decomposition_count(); let d_b = rgsw_by_rgsw_decomposer.b().decomposition_count(); let max_d = std::cmp::max(d_a, d_b); assert!(decomposed_rgsw_i_neg_ais.len() == max_d); // To be RGSW(X^{s[i]}) = [RLWE'(-sm), RLWE'(m)] let mut rgsw_ct_eval = M::zeros(d_a * 2 + d_b * 2, ring_size); let (rlwe_dash_nsm, rlwe_dash_m) = rgsw_ct_eval.split_at_row_mut(d_a * 2); let mut scratch_row = M::R::zeros(ring_size); let mut m_encs_under_ui_eval = m_encs_under_ui.clone(); m_encs_under_ui_eval .iter_rows_mut() .for_each(|r| nttop.forward(r.as_mut())); // RLWE(-sm) { // Recall that we have RLWE(a_i * s + e). We key // switch RLWE(a_i * s + e) using ksk(u_i -> s) to // get RLWE(a_i*s*u_i + e*u_i). // Given (u_i * a_i + e + \beta m), we obtain // RLWE(-sm) = RLWE(a_i*s*u_i + e*u_i) + (0, (u_i * // a_i + e + \beta m)) // // Again RLWE'(-sm) only cares for RLWE(\beta -sm) // with scaling factor \beta corresponding to most // signficant d_a limbs. Hence, we skip (d_max - // d_a) least signficant limbs let (rlwe_dash_neg_sm_part_a, rlwe_dash_neg_sm_part_b) = rlwe_dash_nsm.split_at_mut(d_a); izip!( rlwe_dash_neg_sm_part_a.iter_mut(), rlwe_dash_neg_sm_part_b.iter_mut(), decomposed_acc_rgsw_part1.iter().skip(max_d - d_a), m_encs_under_ui_eval.iter_rows().skip(max_d - d_a) ) .for_each( |(rlwe_a, rlwe_b, decomp_ai_s, beta_m_enc_ui)| { // RLWE_s(a_i * s * u_i + u_i * e) = decomp // * ksk(u_i // -> s) izip!( decomp_ai_s.iter_rows(), user_uitos_ksk_partb_eval.iter_rows(), user_uitos_ksk_parta_eval.iter_rows() ) .for_each( |(a0, part_b, part_a)| { // rlwe_b += decomp[i] * ksk // part_b[i] rlwe_modop.elwise_mul( scratch_row.as_mut(), a0.as_ref(), part_b.as_ref(), ); rlwe_modop.elwise_add_mut( rlwe_b.as_mut(), scratch_row.as_ref(), ); // rlwe_a += decomp[i] * ksk // part_a[i] rlwe_modop.elwise_mul( scratch_row.as_mut(), a0.as_ref(), part_a.as_ref(), ); rlwe_modop.elwise_add_mut( rlwe_a.as_mut(), scratch_row.as_ref(), ); }, ); // RLWE_s(-sm) = RLWE_s(a_i * s * u_i + u_i // * e) + (0, a_i * u + e + m) rlwe_modop.elwise_add_mut( rlwe_a.as_mut(), beta_m_enc_ui.as_ref(), ); }, ); } // RLWE(m) { // Routine: // Let RLWE(-a_i * u_i) = (decomp<-a_i> \cdot ksk(u_i -> s)), // then RLWE(m) = RLWE(a'*s + e + m) = (a_i // * u_i + e + m, 0) + RLWE(-a_i * u_i) // // Since RLWE'(m) only cares for RLWE ciphertexts corresponding // to higher d_b limbs, we skip routine 1 for lower max(d_a, // d_b) - d_b limbs let (rlwe_dash_m_part_a, rlwe_dash_m_part_b) = rlwe_dash_m.split_at_mut(d_b); izip!( rlwe_dash_m_part_a.iter_mut(), rlwe_dash_m_part_b.iter_mut(), decomposed_rgsw_i_neg_ais.iter().skip(max_d - d_b), m_encs_under_ui_eval.iter_rows().skip(max_d - d_b) ) .for_each( |(rlwe_a, rlwe_b, decomp_neg_ai, beta_m_enc_ui)| { // RLWE_s(-a_i * ui) = decomp<-a_i> \cdot ksk(ui -> s) izip!( decomp_neg_ai.iter_rows(), user_uitos_ksk_partb_eval.iter_rows(), user_uitos_ksk_parta_eval.iter_rows() ) .for_each( |(a0, part_b, part_a)| { // rlwe_b += decomp[i] * ksk part_b[i] rlwe_modop.elwise_mul( scratch_row.as_mut(), a0.as_ref(), part_b.as_ref(), ); rlwe_modop.elwise_add_mut( rlwe_b.as_mut(), scratch_row.as_ref(), ); // rlwe_a += decomp[i] * ksk // part_a[i] rlwe_modop.elwise_mul( scratch_row.as_mut(), a0.as_ref(), part_a.as_ref(), ); rlwe_modop.elwise_add_mut( rlwe_a.as_mut(), scratch_row.as_ref(), ); }, ); // RLWE_s(m) = (a_i * ui + e + \beta m, 0) // + // RLWE_s(-a_i * ui) rlwe_modop.elwise_add_mut( rlwe_b.as_mut(), beta_m_enc_ui.as_ref(), ); }, ); } rgsw_ct_eval }, ) .collect_vec(); rgsw_cts_user_i_eval }, ) .collect_vec(); // put u_i -> s ksks back in coefficient domain ui_to_s_ksks.iter_mut().for_each(|ksk_i| { ksk_i .iter_rows_mut() .for_each(|r| nttop.backward(r.as_mut())) }); rgsw_cts_all_users_eval }; // RGSW x RGSW let lwe_n = self.parameters().lwe_n().0; let mut scratch_matrix = M::zeros( std::cmp::max( rgsw_by_rgsw_decomposer.a().decomposition_count(), rgsw_by_rgsw_decomposer.b().decomposition_count(), ) + (rgsw_by_rgsw_decomposer.a().decomposition_count() * 2 + rgsw_by_rgsw_decomposer.b().decomposition_count() * 2), ring_size, ); let rgsw_cts_untrimmed = (0..lwe_n).map(|s_index| { // copy over s_index^th rgsw ct of user 0. Use it to accumulate RGSW products of // all RGSW ciphertexts at s_index let mut rgsw_i = rgsw_cts_all_users_eval[0][s_index].clone(); rgsw_i .iter_rows_mut() .for_each(|r| nttop.backward(r.as_mut())); rgsw_cts_all_users_eval .iter() .skip(1) .for_each(|user_i_rgsws| { rgsw_by_rgsw_inplace( &mut rgsw_i, &user_i_rgsws[s_index], &rgsw_by_rgsw_decomposer, &mut scratch_matrix, nttop, rlwe_modop, ); }); rgsw_i }); // After this point we don't require RGSW cts for RGSWxRGSW // multiplicaiton anymore. So we trim them to suit RLWExRGSW require for PBS let rgsw_cts = rgsw_cts_untrimmed .map(|rgsw_ct| { trim_rgsw_ct_matrix_from_rgrg_to_rlrg( rgsw_ct, self.parameters().rgsw_by_rgsw_decomposition_params(), self.parameters().rlwe_by_rgsw_decomposition_params(), ) }) .collect_vec(); rgsw_cts }; // auto keys let auto_keys = { let mut auto_keys = HashMap::new(); let auto_elements_dlog = self.parameters().auto_element_dlogs(); for i in auto_elements_dlog.into_iter() { let mut key = M::zeros(self.parameters().auto_decomposition_count().0, ring_size); key_shares.iter().for_each(|s| { let auto_key_share_i = s.auto_keys_share().get(&i).expect("Auto key {i} missing"); assert!( auto_key_share_i.dimension() == (self.parameters().auto_decomposition_count().0, ring_size) ); izip!(key.iter_rows_mut(), auto_key_share_i.iter_rows()).for_each( |(partb_out, partb_share)| { rlwe_modop.elwise_add_mut(partb_out.as_mut(), partb_share.as_ref()); }, ); }); auto_keys.insert(i, key); } auto_keys }; // LWE ksk let lwe_ksk = { let mut lwe_ksk = M::R::zeros(self.parameters().lwe_decomposition_count().0 * ring_size); key_shares.iter().for_each(|s| { assert!( s.lwe_ksk_share().as_ref().len() == self.parameters().lwe_decomposition_count().0 * ring_size ); lwe_modop.elwise_add_mut(lwe_ksk.as_mut(), s.lwe_ksk_share().as_ref()); }); lwe_ksk }; SeededNonInteractiveMultiPartyServerKey::new( ui_to_s_ksks, key_order, rgsw_cts, auto_keys, lwe_ksk, cr_seed.clone(), self.parameters().clone(), ) } pub(super) fn non_interactive_multi_party_key_share< K: NonInteractiveMultiPartyClientKey, >( &self, // TODO(Jay): Should get a common reference seed here and derive the rest. cr_seed: &NonInteractiveMultiPartyCrs<[u8; 32]>, self_index: usize, total_users: usize, client_key: &K, ) -> CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare< M, NonInteractiveMultiPartyCrs<[u8; 32]>, > { assert_eq!( self.parameters().variant(), &ParameterVariant::NonInteractiveMultiParty ); // TODO: check whether parameters support `total_users` let nttop = self.pbs_info().nttop_rlweq(); let rlwe_modop = self.pbs_info().modop_rlweq(); let ring_size = self.pbs_info().rlwe_n(); let rlwe_q = self.parameters().rlwe_q(); let sk_rlwe = client_key.sk_rlwe(); let sk_u_rlwe = client_key.sk_u_rlwe(); let sk_lwe = client_key.sk_lwe(); let (ui_to_s_ksk, zero_encs_for_others) = DefaultSecureRng::with_local_mut(|rng| { // ui_to_s_ksk let non_interactive_decomposer = self .parameters() .non_interactive_ui_to_s_key_switch_decomposer::>( ); let non_interactive_gadget_vec = non_interactive_decomposer.gadget_vector(); let ui_to_s_ksk = { let mut p_rng = DefaultSecureRng::new_seeded( cr_seed.ui_to_s_ks_seed_for_user_i::(self_index), ); non_interactive_ksk_gen::( &sk_rlwe, &sk_u_rlwe, &non_interactive_gadget_vec, &mut p_rng, rng, nttop, rlwe_modop, ) }; // zero encryptions for others uj_to_s ksk let all_users_except_self = (0..total_users).filter(|x| *x != self_index); let zero_encs_for_others = all_users_except_self .map(|other_user_index| { let mut p_rng = DefaultSecureRng::new_seeded( cr_seed.ui_to_s_ks_seed_for_user_i::(other_user_index), ); let zero_encs = non_interactive_ksk_zero_encryptions_for_other_party_i::( &sk_rlwe, &non_interactive_gadget_vec, &mut p_rng, rng, nttop, rlwe_modop, ); zero_encs }) .collect_vec(); (ui_to_s_ksk, zero_encs_for_others) }); // Non-interactive RGSW cts = (a_i * u_j + e + \beta X^{s[i]}, a_i * s_j + e') let ni_rgsw_cts = DefaultSecureRng::with_local_mut(|rng| { let mut rgsw_cts_prng = DefaultSecureRng::new_seeded(cr_seed.rgsw_cts_seed::()); // generate non-interactive rgsw cts let rgsw_by_rgsw_decomposer = self .parameters() .rgsw_rgsw_decomposer::>(); let ni_rgrg_gadget_vec = { if rgsw_by_rgsw_decomposer.a().decomposition_count() > rgsw_by_rgsw_decomposer.b().decomposition_count() { rgsw_by_rgsw_decomposer.a().gadget_vector() } else { rgsw_by_rgsw_decomposer.b().gadget_vector() } }; let ni_rgsw_cts: (Vec, Vec) = sk_lwe .iter() .map(|s_i| { // X^{s[i]} let mut m = M::R::zeros(ring_size); let s_i = s_i * (self.pbs_info().embedding_factor() as i32); if s_i < 0 { // X^{-s[i]} -> -X^{N+s[i]} m.as_mut()[ring_size - (s_i.abs() as usize)] = rlwe_q.neg_one(); } else { m.as_mut()[s_i as usize] = M::MatElement::one(); } non_interactive_rgsw_ct::( &sk_rlwe, &sk_u_rlwe, m.as_ref(), &ni_rgrg_gadget_vec, &mut rgsw_cts_prng, rng, nttop, rlwe_modop, ) }) .unzip(); ni_rgsw_cts }); // Auto key share let auto_keys_share = { let auto_seed = cr_seed.auto_keys_cts_seed::(); self._common_rountine_multi_party_auto_keys_share_gen(auto_seed, &sk_rlwe) }; // Lwe Ksk share let lwe_ksk_share = { let lwe_ksk_seed = cr_seed.lwe_ksk_cts_seed::(); self._common_rountine_multi_party_lwe_ksk_share_gen(lwe_ksk_seed, &sk_rlwe, &sk_lwe) }; CommonReferenceSeededNonInteractiveMultiPartyServerKeyShare::new( ni_rgsw_cts, ui_to_s_ksk, zero_encs_for_others, auto_keys_share, lwe_ksk_share, self_index, cr_seed.clone(), ) } fn _common_rountine_multi_party_auto_keys_share_gen( &self, auto_seed: ::Seed, sk_rlwe: &[i32], ) -> HashMap { let g = self.pbs_info.parameters.g(); let ring_size = self.pbs_info.parameters.rlwe_n().0; let br_q = self.pbs_info.parameters.br_q(); let rlweq_modop = &self.pbs_info.rlwe_modop; let rlweq_nttop = &self.pbs_info.rlwe_nttop; DefaultSecureRng::with_local_mut(|rng| { let mut p_rng = DefaultSecureRng::new_seeded(auto_seed); let mut auto_keys = HashMap::new(); let auto_gadget = self.pbs_info.auto_decomposer.gadget_vector(); let auto_element_dlogs = self.pbs_info.parameters.auto_element_dlogs(); for i in auto_element_dlogs.into_iter() { let g_pow = if i == 0 { -(g as isize) } else { (g.pow(i as u32) % br_q) as isize }; let mut ksk_out = M::zeros( self.pbs_info.auto_decomposer.decomposition_count(), ring_size, ); galois_key_gen( &mut ksk_out, sk_rlwe, g_pow, &auto_gadget, rlweq_modop, rlweq_nttop, &mut p_rng, rng, ); auto_keys.insert(i, ksk_out); } auto_keys }) } fn _common_rountine_multi_party_lwe_ksk_share_gen( &self, lwe_ksk_seed: ::Seed, sk_rlwe: &[i32], sk_lwe: &[i32], ) -> M::R { DefaultSecureRng::with_local_mut(|rng| { let mut p_rng = DefaultSecureRng::new_seeded(lwe_ksk_seed); let mut lwe_ksk = M::R::zeros( self.pbs_info.lwe_decomposer.decomposition_count() * self.parameters().rlwe_n().0, ); let lwe_modop = &self.pbs_info.lwe_modop; let d_lwe_gadget_vec = self.pbs_info.lwe_decomposer.gadget_vector(); lwe_ksk_keygen( sk_rlwe, sk_lwe, &mut lwe_ksk, &d_lwe_gadget_vec, lwe_modop, &mut p_rng, rng, ); lwe_ksk }) } pub(super) fn multi_party_public_key_share>( &self, cr_seed: [u8; 32], client_key: &K, ) -> CommonReferenceSeededCollectivePublicKeyShare< ::R, [u8; 32], BoolParameters<::MatElement>, > { DefaultSecureRng::with_local_mut(|rng| { let mut share_out = M::R::zeros(self.pbs_info.parameters.rlwe_n().0); let modop = &self.pbs_info.rlwe_modop; let nttop = &self.pbs_info.rlwe_nttop; let mut main_prng = DefaultSecureRng::new_seeded(cr_seed); public_key_share( &mut share_out, &client_key.sk_rlwe(), modop, nttop, &mut main_prng, rng, ); CommonReferenceSeededCollectivePublicKeyShare::new( share_out, cr_seed, self.pbs_info.parameters.clone(), ) }) } pub(super) fn multi_party_decryption_share>( &self, lwe_ct: &M::R, client_key: &K, ) -> ::MatElement { assert!(lwe_ct.as_ref().len() == self.pbs_info.parameters.rlwe_n().0 + 1); let modop = &self.pbs_info.rlwe_modop; let mut neg_s = M::R::try_convert_from(&client_key.sk_rlwe(), &self.pbs_info.parameters.rlwe_q()); modop.elwise_neg_mut(neg_s.as_mut()); let mut neg_sa = M::MatElement::zero(); izip!(lwe_ct.as_ref().iter().skip(1), neg_s.as_ref().iter()).for_each(|(ai, nsi)| { neg_sa = modop.add(&neg_sa, &modop.mul(ai, nsi)); }); let e = DefaultSecureRng::with_local_mut(|rng| { let mut e = RandomGaussianElementInModulus::random(rng, self.pbs_info.parameters.rlwe_q()); e }); let share = modop.add(&neg_sa, &e); share } pub(crate) fn multi_party_decrypt(&self, shares: &[M::MatElement], lwe_ct: &M::R) -> bool { let modop = &self.pbs_info.rlwe_modop; let mut sum_a = M::MatElement::zero(); shares .iter() .for_each(|share_i| sum_a = modop.add(&sum_a, &share_i)); let encoded_m = modop.add(&lwe_ct.as_ref()[0], &sum_a); self.pbs_info.parameters.rlwe_q().decode(encoded_m) } pub(crate) fn pk_encrypt(&self, pk: &M, m: bool) -> M::R { self.pk_encrypt_batched(pk, &vec![m]).remove(0) } /// Encrypts a batch booleans as multiple LWE ciphertexts. /// /// For public key encryption we first encrypt `m` as a RLWE ciphertext and /// then sample extract LWE samples at required indices. /// /// - TODO(Jay:) Communication can be improved by not sample exctracting and /// instead just truncate degree 0 values (part Bs) pub(crate) fn pk_encrypt_batched(&self, pk: &M, m: &[bool]) -> Vec { DefaultSecureRng::with_local_mut(|rng| { let ring_size = self.pbs_info.parameters.rlwe_n().0; assert!( m.len() <= ring_size, "Cannot batch encrypt > ring_size{ring_size} elements at once" ); let modop = &self.pbs_info.rlwe_modop; let nttop = &self.pbs_info.rlwe_nttop; // RLWE(0) // sample ephemeral key u let mut u = vec![0i32; ring_size]; fill_random_ternary_secret_with_hamming_weight(u.as_mut(), ring_size >> 1, rng); let mut u = M::R::try_convert_from(&u, &self.pbs_info.parameters.rlwe_q()); nttop.forward(u.as_mut()); let mut ua = M::R::zeros(ring_size); ua.as_mut().copy_from_slice(pk.get_row_slice(0)); let mut ub = M::R::zeros(ring_size); ub.as_mut().copy_from_slice(pk.get_row_slice(1)); // a*u nttop.forward(ua.as_mut()); modop.elwise_mul_mut(ua.as_mut(), u.as_ref()); nttop.backward(ua.as_mut()); // b*u nttop.forward(ub.as_mut()); modop.elwise_mul_mut(ub.as_mut(), u.as_ref()); nttop.backward(ub.as_mut()); let mut rlwe = M::zeros(2, ring_size); // sample error rlwe.iter_rows_mut().for_each(|ri| { RandomFillGaussianInModulus::<[M::MatElement], CiphertextModulus>::random_fill( rng, &self.pbs_info.parameters.rlwe_q(), ri.as_mut(), ); }); // a*u + e0 modop.elwise_add_mut(rlwe.get_row_mut(0), ua.as_ref()); // b*u + e1 modop.elwise_add_mut(rlwe.get_row_mut(1), ub.as_ref()); //FIXME(Jay): Figure out a way to get Q/8 form modulus let mut m_vec = M::R::zeros(ring_size); izip!(m_vec.as_mut().iter_mut(), m.iter()).for_each(|(m_el, m_bool)| { if *m_bool { // Q/8 *m_el = self.pbs_info.rlwe_q().true_el() } else { // -Q/8 *m_el = self.pbs_info.rlwe_q().false_el() } }); // b*u + e1 + m modop.elwise_add_mut(rlwe.get_row_mut(1), m_vec.as_ref()); // rlwe.set(1, 0, modop.add(rlwe.get(1, 0), &m)); // sample extract index required indices let samples = m.len(); (0..samples) .into_iter() .map(|i| { let mut lwe_out = M::R::zeros(ring_size + 1); sample_extract(&mut lwe_out, &rlwe, modop, i); lwe_out }) .collect_vec() }) } /// TODO(Jay): Fetch client key from thread local pub fn sk_encrypt>( &self, m: bool, client_key: &K, ) -> M::R { //FIXME(Jay): Figure out a way to get Q/8 form modulus let m = if m { // Q/8 self.pbs_info.rlwe_q().true_el() } else { // -Q/8 self.pbs_info.rlwe_q().false_el() }; DefaultSecureRng::with_local_mut(|rng| { let mut lwe_out = M::R::zeros(self.pbs_info.parameters.rlwe_n().0 + 1); encrypt_lwe( &mut lwe_out, &m, &client_key.sk_rlwe(), &self.pbs_info.rlwe_modop, rng, ); lwe_out }) } pub fn sk_decrypt>( &self, lwe_ct: &M::R, client_key: &K, ) -> bool { let m = decrypt_lwe(lwe_ct, &client_key.sk_rlwe(), &self.pbs_info.rlwe_modop); self.pbs_info.rlwe_q().decode(m) } pub(super) fn aggregate_multi_party_server_key_shares( &self, shares: &[CommonReferenceSeededMultiPartyServerKeyShare< M, BoolParameters, S, >], ) -> SeededMultiPartyServerKey> where S: PartialEq + Clone, M: Clone, { assert_eq!(self.parameters().variant(), &ParameterVariant::MultiParty); assert!(shares.len() > 0); let parameters = shares[0].parameters().clone(); let cr_seed = shares[0].cr_seed(); let rlwe_n = parameters.rlwe_n().0; let g = parameters.g() as isize; let rlwe_q = parameters.rlwe_q(); let lwe_q = parameters.lwe_q(); // sanity checks shares.iter().skip(1).for_each(|s| { assert!(s.parameters() == ¶meters); assert!(s.cr_seed() == cr_seed); }); let rlweq_modop = &self.pbs_info.rlwe_modop; let rlweq_nttop = &self.pbs_info.rlwe_nttop; // auto keys let mut auto_keys = HashMap::new(); let auto_elements_dlog = parameters.auto_element_dlogs(); for i in auto_elements_dlog.into_iter() { let mut key = M::zeros(parameters.auto_decomposition_count().0, rlwe_n); shares.iter().for_each(|s| { let auto_key_share_i = s.auto_keys().get(&i).expect("Auto key {i} missing"); assert!( auto_key_share_i.dimension() == (parameters.auto_decomposition_count().0, rlwe_n) ); izip!(key.iter_rows_mut(), auto_key_share_i.iter_rows()).for_each( |(partb_out, partb_share)| { rlweq_modop.elwise_add_mut(partb_out.as_mut(), partb_share.as_ref()); }, ); }); auto_keys.insert(i, key); } // rgsw ciphertext (most expensive part!) let lwe_n = parameters.lwe_n().0; let rgsw_by_rgsw_decomposer = parameters.rgsw_rgsw_decomposer::>(); let mut scratch_matrix = M::zeros( std::cmp::max( rgsw_by_rgsw_decomposer.a().decomposition_count(), rgsw_by_rgsw_decomposer.b().decomposition_count(), ) + (rgsw_by_rgsw_decomposer.a().decomposition_count() * 2 + rgsw_by_rgsw_decomposer.b().decomposition_count() * 2), rlwe_n, ); let mut tmp_rgsw = RgswCiphertext::::empty(rlwe_n, &rgsw_by_rgsw_decomposer, rlwe_q.clone()).data; let rgsw_cts = (0..lwe_n).into_iter().map(|index| { // copy over rgsw ciphertext for index^th secret element from first share and // treat it as accumulating rgsw ciphertext let mut rgsw_i = shares[0].rgsw_cts()[index].clone(); shares.iter().skip(1).for_each(|si| { // copy over si's RGSW[index] ciphertext and send to evaluation domain izip!(tmp_rgsw.iter_rows_mut(), si.rgsw_cts()[index].iter_rows()).for_each( |(to_ri, from_ri)| { to_ri.as_mut().copy_from_slice(from_ri.as_ref()); rlweq_nttop.forward(to_ri.as_mut()) }, ); rgsw_by_rgsw_inplace( &mut rgsw_i, &tmp_rgsw, &rgsw_by_rgsw_decomposer, &mut scratch_matrix, rlweq_nttop, rlweq_modop, ); }); rgsw_i }); // d_a and d_b may differ for RGSWxRGSW multiplication and RLWExRGSW // multiplication. After this point RGSW ciphertexts will only be used for // RLWExRGSW multiplication (in blind rotation). Thus we drop any additional // RLWE ciphertexts in RGSW ciphertexts after RGSw x RGSW multiplication let rgsw_cts = rgsw_cts .map(|ct_i_in| { trim_rgsw_ct_matrix_from_rgrg_to_rlrg( ct_i_in, self.parameters().rgsw_by_rgsw_decomposition_params(), self.parameters().rlwe_by_rgsw_decomposition_params(), ) }) .collect_vec(); // LWE ksks let mut lwe_ksk = M::R::zeros(rlwe_n * parameters.lwe_decomposition_count().0); let lweq_modop = &self.pbs_info.lwe_modop; shares.iter().for_each(|si| { assert!(si.lwe_ksk().as_ref().len() == rlwe_n * parameters.lwe_decomposition_count().0); lweq_modop.elwise_add_mut(lwe_ksk.as_mut(), si.lwe_ksk().as_ref()) }); SeededMultiPartyServerKey::new(rgsw_cts, auto_keys, lwe_ksk, cr_seed.clone(), parameters) } } impl BoolEvaluator where M: MatrixMut + MatrixEntity, M::R: RowMut + RowEntity, M::MatElement: PrimInt + FromPrimitive + One + Copy + Zero + Display + WrappingSub + NumInfo, RlweModOp: VectorOps + ArithmeticOps, LweModOp: VectorOps + ArithmeticOps, NttOp: Ntt, { /// Returns c0 + c1 + Q/4 fn _add_and_shift_lwe_cts(&self, c0: &mut M::R, c1: &M::R) { let modop = &self.pbs_info.rlwe_modop; modop.elwise_add_mut(c0.as_mut(), c1.as_ref()); // +Q/4 c0.as_mut()[0] = modop.add(&c0.as_ref()[0], &self.pbs_info.rlwe_qby4); } /// Returns 2(c0 - c1) + Q/4 fn _subtract_double_lwe_cts(&self, c0: &mut M::R, c1: &M::R) { let modop = &self.pbs_info.rlwe_modop; // c0 - c1 modop.elwise_sub_mut(c0.as_mut(), c1.as_ref()); // double c0.as_mut().iter_mut().for_each(|v| *v = modop.add(v, v)); } } impl BooleanGates for BoolEvaluator where M: MatrixMut + MatrixEntity, M::R: RowMut + RowEntity + Clone, M::MatElement: PrimInt + FromPrimitive + One + Copy + Zero + Display + WrappingSub + NumInfo + From + WrappingAdd, RlweModOp: VectorOps + ArithmeticOps + ShoupMatrixFMA, LweModOp: VectorOps + ArithmeticOps, NttOp: Ntt, Skey: PbsKey::RgswCt, LweKskKey = M>, ::RgswCt: WithShoupRepr, { type Ciphertext = M::R; type Key = Skey; fn nand_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._add_and_shift_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.nand_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ); } fn and_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._add_and_shift_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.and_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ); } fn or_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._add_and_shift_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.or_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ); } fn nor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._add_and_shift_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.nor_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ) } fn xor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._subtract_double_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.xor_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ); } fn xnor_inplace(&mut self, c0: &mut M::R, c1: &M::R, server_key: &Self::Key) { self._subtract_double_lwe_cts(c0, c1); // PBS pbs( &self.pbs_info, &self.xnor_test_vec, c0, server_key, &mut self.scratch_memory.lwe_vector, &mut self.scratch_memory.decomposition_matrix, ); } fn not_inplace(&mut self, c0: &mut M::R) { let modop = &self.pbs_info.rlwe_modop; c0.as_mut().iter_mut().for_each(|v| *v = modop.neg(v)); } fn and( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.and_inplace(&mut out, c1, key); out } fn nand( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.nand_inplace(&mut out, c1, key); out } fn or( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.or_inplace(&mut out, c1, key); out } fn nor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.nor_inplace(&mut out, c1, key); out } fn xnor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.xnor_inplace(&mut out, c1, key); out } fn xor( &mut self, c0: &Self::Ciphertext, c1: &Self::Ciphertext, key: &Self::Key, ) -> Self::Ciphertext { let mut out = c0.clone(); self.xor_inplace(&mut out, c1, key); out } fn not(&mut self, c: &Self::Ciphertext) -> Self::Ciphertext { let mut out = c.clone(); self.not_inplace(&mut out); out } } #[cfg(test)] mod tests { use rand::{thread_rng, Rng}; use rand_distr::Uniform; use crate::{ backend::ModulusPowerOf2, bool::{ keys::{ NonInteractiveServerKeyEvaluationDomain, PublicKey, ShoupNonInteractiveServerKeyEvaluationDomain, }, parameters::{ MP_BOOL_PARAMS, NON_INTERACTIVE_SMALL_MP_BOOL_PARAMS, SMALL_MP_BOOL_PARAMS, SP_TEST_BOOL_PARAMS, }, }, ntt::NttBackendU64, random::{RandomElementInModulus, DEFAULT_RNG}, rgsw::{ self, measure_noise, public_key_encrypt_rlwe, secret_key_encrypt_rlwe, tests::{_measure_noise_rgsw, _sk_encrypt_rlwe}, RgswCiphertext, RgswCiphertextEvaluationDomain, SeededRgswCiphertext, SeededRlweCiphertext, }, utils::{negacyclic_mul, tests::Stats}, }; use super::*; #[test] fn noise_tester() { let bool_evaluator = BoolEvaluator::< Vec>, NttBackendU64, ModularOpsU64>, ModularOpsU64>, ShoupServerKeyEvaluationDomain>>, >::new(SMALL_MP_BOOL_PARAMS); // let (_, collective_pk, _, _, server_key_eval, ideal_client_key) = // _multi_party_all_keygen(&bool_evaluator, 20); let no_of_parties = 16; let lwe_q = bool_evaluator.pbs_info.parameters.lwe_q(); let rlwe_q = bool_evaluator.pbs_info.parameters.rlwe_q(); let lwe_n = bool_evaluator.pbs_info.parameters.lwe_n().0; let rlwe_n = bool_evaluator.pbs_info.parameters.rlwe_n().0; let lwe_modop = &bool_evaluator.pbs_info.lwe_modop; let rlwe_nttop = &bool_evaluator.pbs_info.rlwe_nttop; let rlwe_modop = &bool_evaluator.pbs_info.rlwe_modop; // let rgsw_rgsw_decomposer = &bool_evaluator // .pbs_info // .parameters // .rgsw_rgsw_decomposer::>(); // let rgsw_rgsw_gadget_a = rgsw_rgsw_decomposer.0.gadget_vector(); // let rgsw_rgsw_gadget_b = rgsw_rgsw_decomposer.1.gadget_vector(); let rlwe_rgsw_decomposer = &bool_evaluator.pbs_info.rlwe_rgsw_decomposer; let rlwe_rgsw_gadget_a = rlwe_rgsw_decomposer.0.gadget_vector(); let rlwe_rgsw_gadget_b = rlwe_rgsw_decomposer.1.gadget_vector(); let auto_decomposer = &bool_evaluator.pbs_info.auto_decomposer; let auto_gadget = auto_decomposer.gadget_vector(); let parties = (0..no_of_parties) .map(|_| bool_evaluator.client_key()) .collect_vec(); let mut ideal_rlwe_sk = vec![0i32; bool_evaluator.pbs_info.rlwe_n()]; parties.iter().for_each(|k| { izip!( ideal_rlwe_sk.iter_mut(), InteractiveMultiPartyClientKey::sk_rlwe(k).iter() ) .for_each(|(ideal_i, s_i)| { *ideal_i = *ideal_i + s_i; }); }); let mut ideal_lwe_sk = vec![0i32; bool_evaluator.pbs_info.lwe_n()]; parties.iter().for_each(|k| { izip!( ideal_lwe_sk.iter_mut(), InteractiveMultiPartyClientKey::sk_lwe(k).iter() ) .for_each(|(ideal_i, s_i)| { *ideal_i = *ideal_i + s_i; }); }); // check noise in freshly encrypted RLWE ciphertext (ie var_fresh) if true { let mut rng = DefaultSecureRng::new(); let mut check = Stats { samples: vec![] }; for _ in 0..10 { // generate a new collective public key let mut pk_cr_seed = [0u8; 32]; rng.fill_bytes(&mut pk_cr_seed); let public_key_share = parties .iter() .map(|k| bool_evaluator.multi_party_public_key_share(pk_cr_seed, k)) .collect_vec(); let collective_pk = PublicKey::< Vec>, DefaultSecureRng, ModularOpsU64>, >::from(public_key_share.as_slice()); let mut m = vec![0u64; rlwe_n]; RandomFillUniformInModulus::random_fill(&mut rng, rlwe_q, m.as_mut_slice()); let mut rlwe_ct = vec![vec![0u64; rlwe_n]; 2]; public_key_encrypt_rlwe::<_, _, _, _, i32, _>( &mut rlwe_ct, collective_pk.key(), &m, rlwe_modop, rlwe_nttop, &mut rng, ); let mut m_back = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_ct, &ideal_rlwe_sk, &mut m_back, rlwe_nttop, rlwe_modop, ); rlwe_modop.elwise_sub_mut(m_back.as_mut_slice(), m.as_slice()); check.add_more(Vec::::try_convert_from(&m_back, rlwe_q).as_slice()); } println!("Public key Std: {}", check.std_dev().abs().log2()); } if true { // Generate server key shares let mut rng = DefaultSecureRng::new(); let mut pk_cr_seed = [0u8; 32]; rng.fill_bytes(&mut pk_cr_seed); let public_key_share = parties .iter() .map(|k| bool_evaluator.multi_party_public_key_share(pk_cr_seed, k)) .collect_vec(); let collective_pk = PublicKey::< Vec>, DefaultSecureRng, ModularOpsU64>, >::from(public_key_share.as_slice()); let pbs_cr_seed = [0u8; 32]; rng.fill_bytes(&mut pk_cr_seed); let server_key_shares = parties .iter() .map(|k| { bool_evaluator.multi_party_server_key_share(pbs_cr_seed, collective_pk.key(), k) }) .collect_vec(); let seeded_server_key = bool_evaluator.aggregate_multi_party_server_key_shares(&server_key_shares); // Check noise in RGSW ciphertexts of ideal LWE secret elements if false { let mut check = Stats { samples: vec![] }; izip!(ideal_lwe_sk.iter(), seeded_server_key.rgsw_cts().iter()).for_each( |(s_i, rgsw_ct_i)| { // X^{s[i]} let mut m_si = vec![0u64; rlwe_n]; let s_i = *s_i * (bool_evaluator.pbs_info.embedding_factor as i32); if s_i < 0 { m_si[rlwe_n - (s_i.abs() as usize)] = rlwe_q.neg_one(); } else { m_si[s_i as usize] = 1; } // RLWE'(-sm) let mut neg_s_eval = Vec::::try_convert_from(ideal_rlwe_sk.as_slice(), rlwe_q); rlwe_modop.elwise_neg_mut(&mut neg_s_eval); rlwe_nttop.forward(&mut neg_s_eval); for j in 0..rlwe_rgsw_decomposer.a().decomposition_count() { // RLWE(B^{j} * -s[X]*X^{s_lwe[i]}) // -s[X]*X^{s_lwe[i]}*B_j let mut m_ideal = m_si.clone(); rlwe_nttop.forward(m_ideal.as_mut_slice()); rlwe_modop .elwise_mul_mut(m_ideal.as_mut_slice(), neg_s_eval.as_slice()); rlwe_nttop.backward(m_ideal.as_mut_slice()); rlwe_modop.elwise_scalar_mul_mut( m_ideal.as_mut_slice(), &rlwe_rgsw_gadget_a[j], ); // RLWE(-s*X^{s_lwe[i]}*B_j) let mut rlwe_ct = vec![vec![0u64; rlwe_n]; 2]; rlwe_ct[0].copy_from_slice(&rgsw_ct_i[j]); rlwe_ct[1].copy_from_slice( &rgsw_ct_i[j + rlwe_rgsw_decomposer.a().decomposition_count()], ); let mut m_back = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_ct, &ideal_rlwe_sk, &mut m_back, rlwe_nttop, rlwe_modop, ); // diff rlwe_modop.elwise_sub_mut(&mut m_back, &m_ideal); check.add_more(&Vec::::try_convert_from(&m_back, rlwe_q)); } // RLWE'(m) for j in 0..rlwe_rgsw_decomposer.b().decomposition_count() { // RLWE(B^{j} * X^{s_lwe[i]}) // X^{s_lwe[i]}*B_j let mut m_ideal = m_si.clone(); rlwe_modop.elwise_scalar_mul_mut( m_ideal.as_mut_slice(), &rlwe_rgsw_gadget_b[j], ); // RLWE(X^{s_lwe[i]}*B_j) let mut rlwe_ct = vec![vec![0u64; rlwe_n]; 2]; rlwe_ct[0].copy_from_slice( &rgsw_ct_i [j + (2 * rlwe_rgsw_decomposer.a().decomposition_count())], ); rlwe_ct[1].copy_from_slice( &rgsw_ct_i[j + (2 * rlwe_rgsw_decomposer.a().decomposition_count() + rlwe_rgsw_decomposer.b().decomposition_count())], ); let mut m_back = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_ct, &ideal_rlwe_sk, &mut m_back, rlwe_nttop, rlwe_modop, ); // diff rlwe_modop.elwise_sub_mut(&mut m_back, &m_ideal); check.add_more(&Vec::::try_convert_from(&m_back, rlwe_q)); } }, ); println!( "RGSW Std: {} {} ;; max={}", check.mean(), check.std_dev().abs().log2(), check.samples.iter().max().unwrap() ); } // server key in Evaluation domain let runtime_server_key = ShoupServerKeyEvaluationDomain::from(ServerKeyEvaluationDomain::< _, _, DefaultSecureRng, NttBackendU64, >::from(&seeded_server_key)); // check noise in RLWE x RGSW(X^{s_i}) where RGSW is accunulated RGSW ciphertext if false { let mut check = Stats { samples: vec![] }; ideal_lwe_sk.iter().enumerate().for_each(|(index, s_i)| { let rgsw_ct_i = runtime_server_key.rgsw_ct_lwe_si(index).as_ref(); let mut m = vec![0u64; rlwe_n]; RandomFillUniformInModulus::random_fill(&mut rng, rlwe_q, m.as_mut_slice()); let mut rlwe_ct = vec![vec![0u64; rlwe_n]; 2]; public_key_encrypt_rlwe::<_, _, _, _, i32, _>( &mut rlwe_ct, collective_pk.key(), &m, rlwe_modop, rlwe_nttop, &mut rng, ); let mut rlwe_after = RlweCiphertext::<_, DefaultSecureRng> { data: rlwe_ct.clone(), is_trivial: false, _phatom: PhantomData, }; let mut scratch = vec![ vec![0u64; rlwe_n]; std::cmp::max( rlwe_rgsw_decomposer.0.decomposition_count(), rlwe_rgsw_decomposer.1.decomposition_count() ) + 2 ]; rlwe_by_rgsw( &mut rlwe_after, rgsw_ct_i, &mut scratch, rlwe_rgsw_decomposer, rlwe_nttop, rlwe_modop, ); // m1 = X^{s[i]} let mut m1 = vec![0u64; rlwe_n]; let s_i = *s_i * (bool_evaluator.pbs_info.embedding_factor as i32); if s_i < 0 { m1[rlwe_n - (s_i.abs() as usize)] = rlwe_q.neg_one() } else { m1[s_i as usize] = 1; } // (m+e) * m1 let mut m_plus_e_times_m1 = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_ct, &ideal_rlwe_sk, &mut m_plus_e_times_m1, rlwe_nttop, rlwe_modop, ); rlwe_nttop.forward(m_plus_e_times_m1.as_mut_slice()); rlwe_nttop.forward(m1.as_mut_slice()); rlwe_modop.elwise_mul_mut(m_plus_e_times_m1.as_mut_slice(), m1.as_slice()); rlwe_nttop.backward(m_plus_e_times_m1.as_mut_slice()); // Resulting RLWE ciphertext will equal: (m0m1 + em1) + e_{rlsw x rgsw}. // Hence, resulting rlwe ciphertext will have error em1 + e_{rlwe x rgsw}. // Here we're only concerned with e_{rlwe x rgsw}, that is noise added by // RLWExRGSW. Also note in practice m1 is a monomial, for ex, X^{s_{i}}, for // some i and var(em1) = var(e). let mut m_plus_e_times_m1_more_e = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_after, &ideal_rlwe_sk, &mut m_plus_e_times_m1_more_e, rlwe_nttop, rlwe_modop, ); // diff rlwe_modop.elwise_sub_mut( m_plus_e_times_m1_more_e.as_mut_slice(), m_plus_e_times_m1.as_slice(), ); // let noise = measure_noise( // &rlwe_after, // &m_plus_e_times_m1, // rlwe_nttop, // rlwe_modop, // ideal_client_key.sk_rlwe.values(), // ); // print!("NOISE: {}", noise); check.add_more(&Vec::::try_convert_from( &m_plus_e_times_m1_more_e, rlwe_q, )); }); println!( "RLWE x RGSW, where RGSW has noise var_brk, std: {} {}", check.std_dev(), check.std_dev().abs().log2() ) } // check noise in Auto key if false { let mut check = Stats { samples: vec![] }; let mut neg_s_poly = Vec::::try_convert_from(ideal_rlwe_sk.as_slice(), rlwe_q); rlwe_modop.elwise_neg_mut(neg_s_poly.as_mut_slice()); let g = bool_evaluator.pbs_info.g(); let br_q = bool_evaluator.pbs_info.br_q(); let auto_element_dlogs = bool_evaluator.pbs_info.parameters.auto_element_dlogs(); for i in auto_element_dlogs.into_iter() { let g_pow = if i == 0 { -g } else { (((g as usize).pow(i as u32)) % br_q) as isize }; // -s[X^k] let (auto_indices, auto_sign) = generate_auto_map(rlwe_n, g_pow); let mut neg_s_poly_auto_i = vec![0u64; rlwe_n]; izip!(neg_s_poly.iter(), auto_indices.iter(), auto_sign.iter()).for_each( |(v, to_i, to_sign)| { if !to_sign { neg_s_poly_auto_i[*to_i] = rlwe_modop.neg(v); } else { neg_s_poly_auto_i[*to_i] = *v; } }, ); let mut auto_key_i = runtime_server_key.galois_key_for_auto(i).as_ref().clone(); //send i^th auto key to coefficient domain auto_key_i .iter_mut() .for_each(|r| rlwe_nttop.backward(r.as_mut_slice())); auto_gadget.iter().enumerate().for_each(|(i, b_i)| { // B^i * -s[X^k] let mut m_ideal = neg_s_poly_auto_i.clone(); rlwe_modop.elwise_scalar_mul_mut(m_ideal.as_mut_slice(), b_i); let mut m_out = vec![0u64; rlwe_n]; let mut rlwe_ct = vec![vec![0u64; rlwe_n]; 2]; rlwe_ct[0].copy_from_slice(&auto_key_i[i]); rlwe_ct[1].copy_from_slice( &auto_key_i[auto_decomposer.decomposition_count() + i], ); decrypt_rlwe(&rlwe_ct, &ideal_rlwe_sk, &mut m_out, rlwe_nttop, rlwe_modop); // diff rlwe_modop.elwise_sub_mut(m_out.as_mut_slice(), m_ideal.as_slice()); check.add_more(&Vec::::try_convert_from(&m_out, rlwe_q)); }); } println!("Auto key noise std dev: {}", check.std_dev().abs().log2()); } // check noise in RLWE(X^k) after sending RLWE(X) -> RLWE(X^k)using collective // auto key if true { let mut check = Stats { samples: vec![] }; let br_q = bool_evaluator.pbs_info.br_q(); let g = bool_evaluator.pbs_info.g(); let auto_element_dlogs = bool_evaluator.pbs_info.parameters.auto_element_dlogs(); for i in auto_element_dlogs.into_iter() { for _ in 0..10 { let mut m = vec![0u64; rlwe_n]; RandomFillUniformInModulus::random_fill(&mut rng, rlwe_q, m.as_mut_slice()); let mut rlwe_ct = RlweCiphertext::<_, DefaultSecureRng> { data: vec![vec![0u64; rlwe_n]; 2], is_trivial: false, _phatom: PhantomData, }; public_key_encrypt_rlwe::<_, _, _, _, i32, _>( &mut rlwe_ct, collective_pk.key(), &m, rlwe_modop, rlwe_nttop, &mut rng, ); // We're only interested in noise increased as a result of automorphism. // Hence, we take m+e as the bench. let mut m_plus_e = vec![0u64; rlwe_n]; decrypt_rlwe( &rlwe_ct, &ideal_rlwe_sk, &mut m_plus_e, rlwe_nttop, rlwe_modop, ); let auto_key = runtime_server_key.galois_key_for_auto(i).as_ref(); let (auto_map_index, auto_map_sign) = bool_evaluator.pbs_info.rlwe_auto_map(i); let mut scratch = vec![vec![0u64; rlwe_n]; auto_decomposer.decomposition_count() + 2]; galois_auto( &mut rlwe_ct, auto_key, &mut scratch, &auto_map_index, &auto_map_sign, rlwe_modop, rlwe_nttop, auto_decomposer, ); // send m+e from X to X^k let mut m_plus_e_auto = vec![0u64; rlwe_n]; izip!(m_plus_e.iter(), auto_map_index.iter(), auto_map_sign.iter()) .for_each(|(v, to_index, to_sign)| { if !to_sign { m_plus_e_auto[*to_index] = rlwe_modop.neg(v); } else { m_plus_e_auto[*to_index] = *v } }); let mut m_out = vec![0u64; rlwe_n]; decrypt_rlwe(&rlwe_ct, &ideal_rlwe_sk, &mut m_out, rlwe_nttop, rlwe_modop); // diff rlwe_modop.elwise_sub_mut(m_out.as_mut_slice(), m_plus_e_auto.as_slice()); check.add_more(&Vec::::try_convert_from(m_out.as_slice(), rlwe_q)); } } println!("Rlwe Auto Noise Std: {}", check.std_dev().abs().log2()); } // Check noise growth in ksk // TODO check in LWE key switching keys if true { // 1. encrypt LWE ciphertext // 2. Key switching // 3. let mut check = Stats { samples: vec![] }; for _ in 0..1024 { // Encrypt m \in Q_{ks} using RLWE sk let mut lwe_in_ct = vec![0u64; rlwe_n + 1]; let m = RandomElementInModulus::random(&mut rng, &lwe_q.q().unwrap()); encrypt_lwe(&mut lwe_in_ct, &m, &ideal_rlwe_sk, lwe_modop, &mut rng); // Key switch let mut lwe_out = vec![0u64; lwe_n + 1]; lwe_key_switch( &mut lwe_out, &lwe_in_ct, runtime_server_key.lwe_ksk(), lwe_modop, bool_evaluator.pbs_info.lwe_decomposer(), ); // We only care about noise added by LWE key switch // m+e let m_plus_e = decrypt_lwe(&lwe_in_ct, &ideal_rlwe_sk, lwe_modop); let m_plus_e_plus_lwe_ksk_noise = decrypt_lwe(&lwe_out, &ideal_lwe_sk, lwe_modop); let diff = lwe_modop.sub(&m_plus_e_plus_lwe_ksk_noise, &m_plus_e); check.add_more(&vec![lwe_q.map_element_to_i64(&diff)]); } println!("Lwe ksk std dev: {}", check.std_dev().abs().log2()); } } // Check noise in fresh RGSW ciphertexts, ie X^{s_j[i]}, must equalnoise in // // fresh RLWE ciphertext if true {} // test LWE ksk from RLWE -> LWE // if false { // let logp = 2; // let mut rng = DefaultSecureRng::new(); // let m = 1; // let encoded_m = m << (lwe_logq - logp); // // Encrypt // let mut lwe_ct = vec![0u64; rlwe_n + 1]; // encrypt_lwe( // &mut lwe_ct, // &encoded_m, // ideal_client_key.sk_rlwe.values(), // lwe_modop, // &mut rng, // ); // // key switch // let lwe_decomposer = &bool_evaluator.decomposer_lwe; // let mut lwe_out = vec![0u64; lwe_n + 1]; // lwe_key_switch( // &mut lwe_out, // &lwe_ct, // &server_key_eval.lwe_ksk, // lwe_modop, // lwe_decomposer, // ); // let encoded_m_back = decrypt_lwe(&lwe_out, // ideal_client_key.sk_lwe.values(), lwe_modop); let m_back // = ((encoded_m_back as f64 * (1 << logp) as f64) / // (lwe_q as f64)).round() as u64; dbg!(m_back, m); // let noise = measure_noise_lwe( // &lwe_out, // ideal_client_key.sk_lwe.values(), // lwe_modop, // &encoded_m, // ); // println!("Noise: {noise}"); // } // Measure noise in RGSW ciphertexts of ideal LWE secrets // if true { // let gadget_vec = gadget_vector( // bool_evaluator.parameters.rlwe_logq, // bool_evaluator.parameters.logb_rgsw, // bool_evaluator.parameters.d_rgsw, // ); // for i in 0..20 { // // measure noise in RGSW(s[i]) // let si = // ideal_client_key.sk_lwe.values[i] * // (bool_evaluator.embedding_factor as i32); let mut // si_poly = vec![0u64; rlwe_n]; if si < 0 { // si_poly[rlwe_n - (si.abs() as usize)] = rlwe_q - 1; // } else { // si_poly[(si.abs() as usize)] = 1; // } // let mut rgsw_si = server_key_eval.rgsw_cts[i].clone(); // rgsw_si // .iter_mut() // .for_each(|ri| rlwe_nttop.backward(ri.as_mut())); // println!("####### Noise in RGSW(X^s_{i}) #######"); // _measure_noise_rgsw( // &rgsw_si, // &si_poly, // ideal_client_key.sk_rlwe.values(), // &gadget_vec, // rlwe_q, // ); // println!("####### ##################### #######"); // } // } // // measure noise grwoth in RLWExRGSW // if true { // let mut rng = DefaultSecureRng::new(); // let mut carry_m = vec![0u64; rlwe_n]; // RandomUniformDist1::random_fill(&mut rng, &rlwe_q, // carry_m.as_mut_slice()); // // RGSW(carrym) // let trivial_rlwect = vec![vec![0u64; rlwe_n],carry_m.clone()]; // let mut rlwe_ct = RlweCiphertext::<_, // DefaultSecureRng>::from_raw(trivial_rlwect, true); // let mut scratch_matrix_dplus2_ring = vec![vec![0u64; rlwe_n]; // d_rgsw + 2]; let mul_mod = // |v0: &u64, v1: &u64| (((*v0 as u128 * *v1 as u128) % (rlwe_q as u128)) as u64); // for i in 0..bool_evaluator.parameters.lwe_n { // rlwe_by_rgsw( // &mut rlwe_ct, // server_key_eval.rgsw_ct_lwe_si(i), // &mut scratch_matrix_dplus2_ring, // rlwe_decomposer, // rlwe_nttop, // rlwe_modop, // ); // // carry_m[X] * s_i[X] // let si = // ideal_client_key.sk_lwe.values[i] * // (bool_evaluator.embedding_factor as i32); let mut // si_poly = vec![0u64; rlwe_n]; if si < 0 { // si_poly[rlwe_n - (si.abs() as usize)] = rlwe_q - 1; // } else { // si_poly[(si.abs() as usize)] = 1; // } // carry_m = negacyclic_mul(&carry_m, &si_poly, mul_mod, // rlwe_q); // let noise = measure_noise( // &rlwe_ct, // &carry_m, // rlwe_nttop, // rlwe_modop, // ideal_client_key.sk_rlwe.values(), // ); // println!("Noise RLWE(carry_m) accumulating {i}^th secret // monomial: {noise}"); } // } // // Check galois keys // if false { // let g = bool_evaluator.g() as isize; // let mut rng = DefaultSecureRng::new(); // let mut scratch_matrix_dplus2_ring = vec![vec![0u64; rlwe_n]; // d_rgsw + 2]; for i in [g, -g] { // let mut m = vec![0u64; rlwe_n]; // RandomUniformDist1::random_fill(&mut rng, &rlwe_q, // m.as_mut_slice()); let mut rlwe_ct = { // let mut data = vec![vec![0u64; rlwe_n]; 2]; // public_key_encrypt_rlwe( // &mut data, // &collective_pk.key, // &m, // rlwe_modop, // rlwe_nttop, // &mut rng, // ); // RlweCiphertext::<_, DefaultSecureRng>::from_raw(data, // false) }; // let auto_key = server_key_eval.galois_key_for_auto(i); // let (auto_map_index, auto_map_sign) = // generate_auto_map(rlwe_n, i); galois_auto( // &mut rlwe_ct, // auto_key, // &mut scratch_matrix_dplus2_ring, // &auto_map_index, // &auto_map_sign, // rlwe_modop, // rlwe_nttop, // rlwe_decomposer, // ); // // send m(X) -> m(X^i) // let mut m_k = vec![0u64; rlwe_n]; // izip!(m.iter(), auto_map_index.iter(), // auto_map_sign.iter()).for_each( |(mi, to_index,to_sign)| // // { if !to_sign { // m_k[*to_index] = rlwe_q - *mi; } else { // m_k[*to_index] = *mi; // } // }, // ); // // measure noise // let noise = measure_noise( // &rlwe_ct, // &m_k, // rlwe_nttop, // rlwe_modop, // ideal_client_key.sk_rlwe.values(), // ); // println!("Noise after auto k={i}: {noise}"); // } // } } #[test] fn testtest() { let evaluator = BoolEvaluator::< Vec>, NttBackendU64, ModularOpsU64>, ModulusPowerOf2>, ShoupNonInteractiveServerKeyEvaluationDomain>>, >::new(NON_INTERACTIVE_SMALL_MP_BOOL_PARAMS); let mp_seed = NonInteractiveMultiPartyCrs { seed: [1u8; 32] }; let ring_size = evaluator.parameters().rlwe_n().0; let rlwe_q = evaluator.parameters().rlwe_q(); let rlwe_modop = evaluator.pbs_info().modop_rlweq(); let nttop = evaluator.pbs_info().nttop_rlweq(); let parties = 2; let cks = (0..parties).map(|_| evaluator.client_key()).collect_vec(); let key_shares = (0..parties) .map(|i| evaluator.non_interactive_multi_party_key_share(&mp_seed, i, parties, &cks[i])) .collect_vec(); // dbg!(key_shares[1].user_index); let seeded_server_key = evaluator.aggregate_non_interactive_multi_party_key_share( &mp_seed, parties, &key_shares, ); let server_key_evaluation_domain = NonInteractiveServerKeyEvaluationDomain::<_, _, DefaultSecureRng, NttBackendU64>::from( &seeded_server_key, ); let mut ideal_rlwe = vec![0; ring_size]; cks.iter().for_each(|k| { izip!( ideal_rlwe.iter_mut(), NonInteractiveMultiPartyClientKey::sk_rlwe(k).iter() ) .for_each(|(a, b)| { *a = *a + b; }); }); let mut ideal_lwe = vec![0; evaluator.parameters().lwe_n().0]; cks.iter().for_each(|k| { izip!( ideal_lwe.iter_mut(), NonInteractiveMultiPartyClientKey::sk_lwe(k).iter() ) .for_each(|(a, b)| { *a = *a + b; }); }); let mut stats = Stats::new(); { let (rlrg_decomp_a, rlrg_decomp_b) = evaluator .parameters() .rlwe_rgsw_decomposer::>(); let gadget_vec_a = rlrg_decomp_a.gadget_vector(); let gadget_vec_b = rlrg_decomp_b.gadget_vector(); let d_a = rlrg_decomp_a.decomposition_count(); let d_b = rlrg_decomp_b.decomposition_count(); // s[X] let s_poly = Vec::::try_convert_from(ideal_rlwe.as_slice(), rlwe_q); // -s[X] let mut neg_s_poly_eval = s_poly.clone(); rlwe_modop.elwise_neg_mut(&mut neg_s_poly_eval); nttop.forward(neg_s_poly_eval.as_mut()); server_key_evaluation_domain .rgsw_cts() .iter() .enumerate() .for_each(|(s_index, ct)| { // X^{lwe_s[i]} let mut m = vec![0u64; ring_size]; let s_i = ideal_lwe[s_index] * (evaluator.pbs_info().embedding_factor() as i32); if s_i < 0 { m[ring_size - (s_i.abs() as usize)] = rlwe_q.neg_one(); } else { m[(s_i as usize)] = 1; } let mut neg_sm = m.clone(); nttop.forward(&mut neg_sm); rlwe_modop.elwise_mul_mut(&mut neg_sm, &neg_s_poly_eval); nttop.backward(&mut neg_sm); // RLWE'(-sm) gadget_vec_a.iter().enumerate().for_each(|(index, beta)| { // RLWE(\beta -sm) // \beta * -sX^[lwe_s[i]] let mut beta_neg_sm = neg_sm.clone(); rlwe_modop.elwise_scalar_mul_mut(&mut beta_neg_sm, beta); // extract RLWE(-sm \beta) let mut rlwe = vec![vec![0u64; ring_size]; 2]; rlwe[0].copy_from_slice(&ct[index]); rlwe[1].copy_from_slice(&ct[index + d_a]); // send back to coefficient domain rlwe.iter_rows_mut() .for_each(|r| nttop.backward(r.as_mut_slice())); // decrypt let mut m_out = vec![0u64; ring_size]; decrypt_rlwe(&rlwe, &ideal_rlwe, &mut m_out, nttop, rlwe_modop); // println!("{:?}", &beta_neg_sm); let mut diff = m_out; rlwe_modop.elwise_sub_mut(&mut diff, &beta_neg_sm); stats.add_more(&Vec::::try_convert_from(&diff, rlwe_q)); }); }); } println!("Stats: {}", stats.std_dev().abs().log2()); } }