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phantom-zone/src/bool/evaluator.rs

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use std::{
borrow::BorrowMut,
cell::{OnceCell, RefCell},
clone,
collections::HashMap,
fmt::{Debug, Display},
iter::Once,
marker::PhantomData,
ops::Shr,
sync::OnceLock,
};
use itertools::{izip, partition, Itertools};
use num_traits::{FromPrimitive, Num, One, Pow, PrimInt, ToPrimitive, WrappingSub, Zero};
use rand_distr::uniform::SampleUniform;
use crate::{
backend::{ArithmeticOps, GetModulus, ModInit, ModularOpsU64, Modulus, VectorOps},
decomposer::{Decomposer, DefaultDecomposer, NumInfo, RlweDecomposer},
lwe::{decrypt_lwe, encrypt_lwe, lwe_key_switch, lwe_ksk_keygen, measure_noise_lwe, LweSecret},
multi_party::public_key_share,
ntt::{self, Ntt, NttBackendU64, NttInit},
pbs::{pbs, sample_extract, PbsInfo, PbsKey},
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, Global,
TryConvertFrom1, WithLocal,
},
Decryptor, Encryptor, Matrix, MatrixEntity, MatrixMut, MultiPartyDecryptor, Row, RowEntity,
RowMut, Secret,
};
use super::{
keys::ClientKey,
parameters::{BoolParameters, CiphertextModulus},
CommonReferenceSeededCollectivePublicKeyShare, CommonReferenceSeededMultiPartyServerKeyShare,
SeededMultiPartyServerKey, SeededServerKey, ServerKeyEvaluationDomain,
};
pub struct MultiPartyCrs<S> {
pub(super) seed: S,
}
impl<S: Default + Copy> MultiPartyCrs<S> {
/// 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<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
let mut prng = Rng::new_with_seed(self.seed);
let mut seed = S::default();
RandomFill::<S>::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<Rng: NewWithSeed<Seed = S> + RandomFill<S>>(&self) -> S {
let mut prng = Rng::new_with_seed(self.seed);
let mut seed = S::default();
RandomFill::<S>::random_fill(&mut prng, &mut seed);
RandomFill::<S>::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<M>
where
M: Matrix,
{
lwe_vector: M::R,
decomposition_matrix: M,
}
impl<M: MatrixEntity> ScratchMemory<M>
where
M::R: RowEntity,
{
fn new(parameters: &BoolParameters<M::MatElement>) -> 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<T> BoolEncoding for CiphertextModulus<T>
where
CiphertextModulus<T>: Modulus<Element = T>,
T: PrimInt,
{
type Element = T;
fn qby4(&self) -> Self::Element {
if self.is_native() {
T::one() << (CiphertextModulus::<T>::_bits() - 2)
} else {
self.q().unwrap() >> 2
}
}
/// Q/8
fn true_el(&self) -> Self::Element {
if self.is_native() {
T::one() << (CiphertextModulus::<T>::_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")
}
}
}
pub(super) struct BoolPbsInfo<M: Matrix, Ntt, RlweModOp, LweModOp> {
auto_decomposer: DefaultDecomposer<M::MatElement>,
rlwe_rgsw_decomposer: (
DefaultDecomposer<M::MatElement>,
DefaultDecomposer<M::MatElement>,
),
lwe_decomposer: DefaultDecomposer<M::MatElement>,
g_k_dlog_map: Vec<usize>,
rlwe_nttop: Ntt,
rlwe_modop: RlweModOp,
lwe_modop: LweModOp,
embedding_factor: usize,
rlwe_qby4: M::MatElement,
rlwe_auto_maps: Vec<(Vec<usize>, Vec<bool>)>,
parameters: BoolParameters<M::MatElement>,
}
impl<M: Matrix, NttOp, RlweModOp, LweModOp> PbsInfo for BoolPbsInfo<M, NttOp, RlweModOp, LweModOp>
where
M::MatElement: PrimInt + WrappingSub + NumInfo + FromPrimitive + From<bool> + Display,
RlweModOp: ArithmeticOps<Element = M::MatElement> + VectorOps<Element = M::MatElement>,
LweModOp: ArithmeticOps<Element = M::MatElement> + VectorOps<Element = M::MatElement>,
NttOp: Ntt<Element = M::MatElement>,
{
type Modulus = CiphertextModulus<M::MatElement>;
type Element = M::MatElement;
type D = DefaultDecomposer<M::MatElement>;
type RlweModOp = RlweModOp;
type LweModOp = LweModOp;
type NttOp = NttOp;
fn rlwe_auto_map(&self, k: usize) -> &(Vec<usize>, Vec<bool>) {
&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<M, Ntt, RlweModOp, LweModOp>
where
M: Matrix,
{
pbs_info: BoolPbsInfo<M, Ntt, RlweModOp, LweModOp>,
scratch_memory: ScratchMemory<M>,
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,
_phantom: PhantomData<M>,
}
impl<M: Matrix, NttOp, RlweModOp, LweModOp> BoolEvaluator<M, NttOp, RlweModOp, LweModOp> {
pub(super) fn parameters(&self) -> &BoolParameters<M::MatElement> {
&self.pbs_info.parameters
}
pub(super) fn pbs_info(&self) -> &BoolPbsInfo<M, NttOp, RlweModOp, LweModOp> {
&self.pbs_info
}
}
impl<M: Matrix, NttOp, RlweModOp, LweModOp> BoolEvaluator<M, NttOp, RlweModOp, LweModOp>
where
M: MatrixEntity + MatrixMut,
M::MatElement: PrimInt
+ Debug
+ Display
+ NumInfo
+ FromPrimitive
+ WrappingSub
+ SampleUniform
+ From<bool>,
NttOp: Ntt<Element = M::MatElement>,
RlweModOp: ArithmeticOps<Element = M::MatElement>
+ VectorOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
LweModOp: ArithmeticOps<Element = M::MatElement>
+ VectorOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
M::R: TryConvertFrom1<[i32], CiphertextModulus<M::MatElement>> + RowEntity + Debug,
<M as Matrix>::R: RowMut,
{
pub(super) fn new(parameters: BoolParameters<M::MatElement>) -> Self
where
RlweModOp: ModInit<M = CiphertextModulus<M::MatElement>>,
LweModOp: ModInit<M = CiphertextModulus<M::MatElement>>,
NttOp: NttInit<CiphertextModulus<M::MatElement>>,
{
//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(&parameters);
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,
_phantom: PhantomData,
}
}
pub(super) fn client_key(&self) -> ClientKey {
let sk_lwe = LweSecret::random(
self.pbs_info.parameters.lwe_n().0 >> 1,
self.pbs_info.parameters.lwe_n().0,
);
let sk_rlwe = RlweSecret::random(
self.pbs_info.parameters.rlwe_n().0 >> 1,
self.pbs_info.parameters.rlwe_n().0,
);
ClientKey::new(sk_rlwe, sk_lwe)
}
pub(super) fn server_key(
&self,
client_key: &ClientKey,
) -> SeededServerKey<M, BoolParameters<M::MatElement>, [u8; 32]> {
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.values(),
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
.values()
.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.values(),
&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.values(),
&sk_lwe.values(),
&mut lwe_ksk,
&d_lwe_gadget,
&self.pbs_info.lwe_modop,
&mut main_prng,
rng,
);
SeededServerKey::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: &ClientKey,
) -> CommonReferenceSeededMultiPartyServerKeyShare<M, BoolParameters<M::MatElement>, [u8; 32]>
{
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.values().len() == ring_size);
assert!(sk_lwe.values().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.values(),
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::<DefaultDecomposer<M::MatElement>>();
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
.values()
.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.values(),
sk_lwe.values(),
&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 multi_party_public_key_share(
&self,
cr_seed: [u8; 32],
client_key: &ClientKey,
) -> CommonReferenceSeededCollectivePublicKeyShare<
<M as Matrix>::R,
[u8; 32],
BoolParameters<<M as Matrix>::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().values(),
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: &ClientKey,
) -> <M as Matrix>::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().values(),
&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<M::R> {
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<M::MatElement>>::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: &ClientKey) -> 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().values(),
&self.pbs_info.rlwe_modop,
rng,
);
lwe_out
})
}
pub fn sk_decrypt(&self, lwe_ct: &M::R, client_key: &ClientKey) -> bool {
let m = decrypt_lwe(
lwe_ct,
client_key.sk_rlwe().values(),
&self.pbs_info.rlwe_modop,
);
self.pbs_info.rlwe_q().decode(m)
}
pub(super) fn aggregate_multi_party_server_key_shares<S>(
&self,
shares: &[CommonReferenceSeededMultiPartyServerKeyShare<
M,
BoolParameters<M::MatElement>,
S,
>],
) -> SeededMultiPartyServerKey<M, S, BoolParameters<M::MatElement>>
where
S: PartialEq + Clone,
M: Clone,
{
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() == &parameters);
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::<DefaultDecomposer<M::MatElement>>();
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::<M, _>::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 (rgswrgsw_d_a, rgswrgsw_d_b) = self.pbs_info.parameters.rgsw_rgsw_decomposition_count();
let (rlrg_d_a, rlrg_d_b) = self.pbs_info.parameters.rlwe_rgsw_decomposition_count();
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!(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 rgsw_cts = rgsw_cts
.map(|ct_i_in| {
assert!(ct_i_in.dimension() == (rgsw_ct_rows_in, rlwe_n));
let mut reduced_ct_i_out = M::zeros(rgsw_ct_rows_out, rlwe_n);
// RLWE'(-sm) part A
izip!(
reduced_ct_i_out.iter_rows_mut().take(rlrg_d_a.0),
ct_i_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),
ct_i_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),
ct_i_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),
ct_i_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
})
.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<M, NttOp, RlweModOp, LweModOp> BoolEvaluator<M, NttOp, RlweModOp, LweModOp>
where
M: MatrixMut + MatrixEntity,
M::R: RowMut + RowEntity,
M::MatElement: PrimInt + FromPrimitive + One + Copy + Zero + Display + WrappingSub + NumInfo,
RlweModOp: VectorOps<Element = M::MatElement>
+ ArithmeticOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
LweModOp: VectorOps<Element = M::MatElement>
+ ArithmeticOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
NttOp: Ntt<Element = M::MatElement>,
{
/// 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<M, NttOp, RlweModOp, LweModOp> BooleanGates for BoolEvaluator<M, NttOp, RlweModOp, LweModOp>
where
M: MatrixMut + MatrixEntity,
M::R: RowMut + RowEntity + Clone,
M::MatElement:
PrimInt + FromPrimitive + One + Copy + Zero + Display + WrappingSub + NumInfo + From<bool>,
RlweModOp: VectorOps<Element = M::MatElement>
+ ArithmeticOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
LweModOp: VectorOps<Element = M::MatElement>
+ ArithmeticOps<Element = M::MatElement>
+ GetModulus<Element = M::MatElement, M = CiphertextModulus<M::MatElement>>,
NttOp: Ntt<Element = M::MatElement>,
{
type Ciphertext = M::R;
type Key = ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>;
fn nand_inplace(
&mut self,
c0: &mut M::R,
c1: &M::R,
server_key: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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: &ServerKeyEvaluationDomain<M, DefaultSecureRng, NttOp>,
) {
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 bool::parameters::{MP_BOOL_PARAMS, SP_BOOL_PARAMS};
use rand::{thread_rng, Rng};
use rand_distr::Uniform;
use crate::{
backend::{GetModulus, ModInit, ModularOpsU64, WordSizeModulus},
bool::{
self, CommonReferenceSeededMultiPartyServerKeyShare, PublicKey,
SeededMultiPartyServerKey,
},
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, Stats},
};
use super::*;
#[test]
fn bool_encrypt_decrypt_works() {
let bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(SP_BOOL_PARAMS);
let client_key = bool_evaluator.client_key();
let mut m = true;
for _ in 0..1000 {
let lwe_ct = bool_evaluator.sk_encrypt(m, &client_key);
let m_back = bool_evaluator.sk_decrypt(&lwe_ct, &client_key);
assert_eq!(m, m_back);
m = !m;
}
}
#[test]
fn bool_nand() {
let mut bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(SP_BOOL_PARAMS);
// println!("{:?}", bool_evaluator.nand_test_vec);
let client_key = bool_evaluator.client_key();
let seeded_server_key = bool_evaluator.server_key(&client_key);
let server_key_eval_domain =
ServerKeyEvaluationDomain::<_, DefaultSecureRng, NttBackendU64>::from(
&seeded_server_key,
);
let mut m0 = false;
let mut m1 = true;
let mut ct0 = bool_evaluator.sk_encrypt(m0, &client_key);
let mut ct1 = bool_evaluator.sk_encrypt(m1, &client_key);
for _ in 0..500 {
let ct_back = bool_evaluator.nand(&ct0, &ct1, &server_key_eval_domain);
let m_out = !(m0 && m1);
let m_back = bool_evaluator.sk_decrypt(&ct_back, &client_key);
assert!(m_out == m_back, "Expected {m_out}, got {m_back}");
m1 = m0;
m0 = m_out;
ct1 = ct0;
ct0 = ct_back;
}
}
#[test]
fn bool_xor() {
let mut bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(SP_BOOL_PARAMS);
// println!("{:?}", bool_evaluator.nand_test_vec);
let client_key = bool_evaluator.client_key();
let seeded_server_key = bool_evaluator.server_key(&client_key);
let server_key_eval_domain =
ServerKeyEvaluationDomain::<_, DefaultSecureRng, NttBackendU64>::from(
&seeded_server_key,
);
let mut m0 = false;
let mut m1 = true;
let mut ct0 = bool_evaluator.sk_encrypt(m0, &client_key);
let mut ct1 = bool_evaluator.sk_encrypt(m1, &client_key);
for _ in 0..1000 {
let ct_back = bool_evaluator.xor(&ct0, &ct1, &server_key_eval_domain);
let m_out = (m0 ^ m1);
let m_back = bool_evaluator.sk_decrypt(&ct_back, &client_key);
assert!(m_out == m_back, "Expected {m_out}, got {m_back}");
m1 = m0;
m0 = m_out;
ct1 = ct0;
ct0 = ct_back;
}
}
#[test]
fn multi_party_encryption_decryption() {
let bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(MP_BOOL_PARAMS);
let no_of_parties = 500;
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(), k.sk_rlwe().values()).for_each(|(ideal_i, s_i)| {
*ideal_i = *ideal_i + s_i;
});
});
let mut m = true;
for i in 0..100 {
let pk_cr_seed = [0u8; 32];
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<Vec<u64>>,
DefaultSecureRng,
ModularOpsU64<CiphertextModulus<u64>>,
>::from(public_key_share.as_slice());
let lwe_ct = bool_evaluator.pk_encrypt(collective_pk.key(), m);
let decryption_shares = parties
.iter()
.map(|k| bool_evaluator.multi_party_decryption_share(&lwe_ct, k))
.collect_vec();
let m_back = bool_evaluator.multi_party_decrypt(&decryption_shares, &lwe_ct);
{
let ideal_m = if m {
bool_evaluator.pbs_info.parameters.rlwe_q().true_el()
} else {
bool_evaluator.pbs_info.parameters.rlwe_q().false_el()
};
let noise = measure_noise_lwe(
&lwe_ct,
&ideal_rlwe_sk,
&bool_evaluator.pbs_info.rlwe_modop,
&ideal_m,
);
println!("Noise: {noise}");
}
assert_eq!(m_back, m);
m = !m;
}
}
fn _collecitve_public_key_gen(rlwe_q: u64, parties_rlwe_sk: &[RlweSecret]) -> Vec<Vec<u64>> {
let ring_size = parties_rlwe_sk[0].values.len();
assert!(ring_size.is_power_of_two());
let mut rng = DefaultSecureRng::new();
let nttop = NttBackendU64::new(&rlwe_q, ring_size);
let modop = ModularOpsU64::new(rlwe_q);
// Generate Pk shares
let pk_seed = [0u8; 32];
let pk_shares = parties_rlwe_sk.iter().map(|sk| {
let mut p_rng = DefaultSecureRng::new_seeded(pk_seed);
let mut share_out = vec![0u64; ring_size];
public_key_share(
&mut share_out,
sk.values(),
&modop,
&nttop,
&mut p_rng,
&mut rng,
);
share_out
});
let mut pk_part_b = vec![0u64; ring_size];
pk_shares.for_each(|share| modop.elwise_add_mut(&mut pk_part_b, &share));
let mut pk_part_a = vec![0u64; ring_size];
let mut p_rng = DefaultSecureRng::new_seeded(pk_seed);
RandomFillUniformInModulus::random_fill(&mut p_rng, &rlwe_q, pk_part_a.as_mut_slice());
vec![pk_part_a, pk_part_b]
}
fn _multi_party_all_keygen(
bool_evaluator: &BoolEvaluator<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>,
no_of_parties: usize,
) -> (
Vec<ClientKey>,
PublicKey<Vec<Vec<u64>>, DefaultSecureRng, ModularOpsU64<CiphertextModulus<u64>>>,
Vec<
CommonReferenceSeededMultiPartyServerKeyShare<
Vec<Vec<u64>>,
BoolParameters<u64>,
[u8; 32],
>,
>,
SeededMultiPartyServerKey<Vec<Vec<u64>>, [u8; 32], BoolParameters<u64>>,
ServerKeyEvaluationDomain<Vec<Vec<u64>>, DefaultSecureRng, NttBackendU64>,
ClientKey,
) {
let parties = (0..no_of_parties)
.map(|_| bool_evaluator.client_key())
.collect_vec();
let mut rng = DefaultSecureRng::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<Vec<u64>>, DefaultSecureRng, _>::from(public_key_share.as_slice());
// Server key
let mut pbs_cr_seed = [0u8; 32];
rng.fill_bytes(&mut pbs_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);
let server_key_eval = ServerKeyEvaluationDomain::<_, DefaultSecureRng, NttBackendU64>::from(
&seeded_server_key,
);
// construct ideal rlwe sk for meauring noise
let ideal_client_key = {
let mut ideal_rlwe_sk = vec![0i32; bool_evaluator.pbs_info.rlwe_n()];
parties.iter().for_each(|k| {
izip!(ideal_rlwe_sk.iter_mut(), k.sk_rlwe().values()).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(), k.sk_lwe().values()).for_each(|(ideal_i, s_i)| {
*ideal_i = *ideal_i + s_i;
});
});
ClientKey::new(
RlweSecret {
values: ideal_rlwe_sk,
},
LweSecret {
values: ideal_lwe_sk,
},
)
};
(
parties,
collective_pk,
server_key_shares,
seeded_server_key,
server_key_eval,
ideal_client_key,
)
}
#[test]
fn multi_party_nand() {
let mut bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(MP_BOOL_PARAMS);
let (parties, collective_pk, _, _, server_key_eval, ideal_client_key) =
_multi_party_all_keygen(&bool_evaluator, 2);
let mut m0 = true;
let mut m1 = false;
let mut lwe0 = bool_evaluator.pk_encrypt(collective_pk.key(), m0);
let mut lwe1 = bool_evaluator.pk_encrypt(collective_pk.key(), m1);
for _ in 0..2000 {
let lwe_out = bool_evaluator.nand(&lwe0, &lwe1, &server_key_eval);
let m_expected = !(m0 & m1);
// multi-party decrypt
let decryption_shares = parties
.iter()
.map(|k| bool_evaluator.multi_party_decryption_share(&lwe_out, k))
.collect_vec();
let m_back = bool_evaluator.multi_party_decrypt(&decryption_shares, &lwe_out);
// let m_back = bool_evaluator.sk_decrypt(&lwe_out, &ideal_client_key);
assert!(m_expected == m_back, "Expected {m_expected}, got {m_back}");
m1 = m0;
m0 = m_expected;
lwe1 = lwe0;
lwe0 = lwe_out;
}
}
#[test]
fn noise_tester() {
let bool_evaluator = BoolEvaluator::<
Vec<Vec<u64>>,
NttBackendU64,
ModularOpsU64<CiphertextModulus<u64>>,
ModularOpsU64<CiphertextModulus<u64>>,
>::new(SP_BOOL_PARAMS);
// let (_, collective_pk, _, _, server_key_eval, ideal_client_key) =
// _multi_party_all_keygen(&bool_evaluator, 20);
let no_of_parties = 2;
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::<DefaultDecomposer<u64>>();
// 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 ideal_client_key = {
let mut ideal_rlwe_sk = vec![0i32; bool_evaluator.pbs_info.rlwe_n()];
parties.iter().for_each(|k| {
izip!(ideal_rlwe_sk.iter_mut(), k.sk_rlwe().values()).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(), k.sk_lwe().values()).for_each(|(ideal_i, s_i)| {
*ideal_i = *ideal_i + s_i;
});
});
ClientKey::new(
RlweSecret {
values: ideal_rlwe_sk,
},
LweSecret {
values: ideal_lwe_sk,
},
)
};
// 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<Vec<u64>>,
DefaultSecureRng,
ModularOpsU64<CiphertextModulus<u64>>,
>::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_client_key.sk_rlwe().values(),
&mut m_back,
rlwe_nttop,
rlwe_modop,
);
rlwe_modop.elwise_sub_mut(m_back.as_mut_slice(), m.as_slice());
check.add_more(Vec::<i64>::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<Vec<u64>>,
DefaultSecureRng,
ModularOpsU64<CiphertextModulus<u64>>,
>::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_client_key.sk_lwe().values.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::<u64>::try_convert_from(ideal_client_key.sk_rlwe().values(), 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_client_key.sk_rlwe().values(),
&mut m_back,
rlwe_nttop,
rlwe_modop,
);
// diff
rlwe_modop.elwise_sub_mut(&mut m_back, &m_ideal);
check.add_more(&Vec::<i64>::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_client_key.sk_rlwe().values(),
&mut m_back,
rlwe_nttop,
rlwe_modop,
);
// diff
rlwe_modop.elwise_sub_mut(&mut m_back, &m_ideal);
check.add_more(&Vec::<i64>::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 server_key_eval_domain =
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![] };
izip!(
ideal_client_key.sk_lwe().values(),
server_key_eval_domain.rgsw_cts().iter()
)
.for_each(|(s_i, rgsw_ct_i)| {
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,
);
// RLWE(m*X^{s[i]}) = RLWE(m) x RGSW(X^{s[i]})
// let mut rlwe_after = RlweCiphertext::<_, DefaultSecureRng>::new_trivial(vec![
// vec![0u64; rlwe_n],
// m.clone(),
// ]);
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_client_key.sk_rlwe().values(),
&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_client_key.sk_rlwe().values(),
&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::<i64>::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::<u64>::try_convert_from(ideal_client_key.sk_rlwe().values(), 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 = server_key_eval_domain.galois_key_for_auto(i).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_client_key.sk_rlwe().values(),
&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::<i64>::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_client_key.sk_rlwe().values(),
&mut m_plus_e,
rlwe_nttop,
rlwe_modop,
);
let auto_key = server_key_eval_domain.galois_key_for_auto(i);
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_client_key.sk_rlwe().values(),
&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::<i64>::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_client_key.sk_rlwe().values(),
lwe_modop,
&mut rng,
);
// Key switch
let mut lwe_out = vec![0u64; lwe_n + 1];
lwe_key_switch(
&mut lwe_out,
&lwe_in_ct,
server_key_eval_domain.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_client_key.sk_rlwe().values(), lwe_modop);
let m_plus_e_plus_lwe_ksk_noise =
decrypt_lwe(&lwe_out, ideal_client_key.sk_lwe().values(), 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 equal noise 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}");
// }
// }
}
}