A src/multi_party.rs

@@ -0,0 +1,46 @@
+use crate::{
+    backend::VectorOps,
+    ntt::{self, Ntt},
+    random::{NewWithSeed, RandomGaussianDist, RandomUniformDist},
+    utils::TryConvertFrom,
+    Matrix, Row, RowEntity, RowMut,
+};
+
+fn public_key_share<
+    R: Row + RowMut + RowEntity,
+    S,
+    ModOp: VectorOps<Element = R::Element>,
+    NttOp: Ntt<Element = R::Element>,
+    Rng: RandomGaussianDist<[R::Element], Parameters = R::Element>
+        + NewWithSeed
+        + RandomUniformDist<[R::Element], Parameters = R::Element>,
+>(
+    share_out: &mut R,
+    s_i: &[S],
+    modop: &ModOp,
+    nttop: &NttOp,
+    crp_seed: Rng::Seed,
+    rng: &mut Rng,
+) where
+    R: TryConvertFrom<[S], Parameters = R::Element>,
+{
+    let ring_size = share_out.as_ref().len();
+    assert!(s_i.len() == ring_size);
+
+    let q = modop.modulus();
+
+    // a*s
+    let mut a = R::zeros(ring_size);
+    let mut p_rng = Rng::new_with_seed(crp_seed);
+    RandomUniformDist::random_fill(&mut p_rng, &q, a.as_mut());
+    nttop.forward(a.as_mut());
+    let mut s = R::try_convert_from(s_i, &q);
+    nttop.forward(s.as_mut());
+    modop.elwise_mul_mut(s.as_mut(), a.as_ref());
+    nttop.backward(s.as_mut());
+
+    RandomGaussianDist::random_fill(rng, &q, share_out.as_mut());
+    modop.elwise_add_mut(share_out.as_mut(), s.as_ref()); // s*e + e
+}
+
+fn rlwe_galois_auto_key_share<M: Matrix>() {}