test of 20 parties works

src/bool/evaluator.rs

@@ -856,13 +856,16 @@ where
                 .iter()
                 .map(|si| {
                     let mut m = M::R::zeros(ring_size);
-
-                    if *si < 0 {
+                    //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.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 - M::MatElement::one();
                     } else {
-                        m.as_mut()[*si as usize] = M::MatElement::one();
+                        m.as_mut()[si as usize] = M::MatElement::one();
                     }
 
                     // public key RGSW encryption has no part that can be seeded, unlike secret key
@@ -1812,11 +1815,174 @@ mod tests {
     }
 
     #[test]
-    fn mp_key_correcntess() {
-        let bool_evaluator =
-            BoolEvaluator::<Vec<Vec<u64>>, u64, NttBackendU64, ModularOpsU64>::new(MP_BOOL_PARAMS);
+    fn multi_party_lwe_keyswitch() {
+        let lwe_logq = 18;
+        let lwe_q = 1 << lwe_logq;
+        let d_lwe = 4;
+        let logb_lwe = 4;
+        let lwe_gadgect_vec = gadget_vector(lwe_logq, logb_lwe, d_lwe);
+        let lweq_modop = ModularOpsU64::new(lwe_q);
+        let logp = 2;
+
+        let from_lwe_n = 2048;
+        let to_lwe_n = 583;
 
         let no_of_parties = 10;
+        let parties_from_lwe_sk = (0..no_of_parties)
+            .map(|_| LweSecret::random(from_lwe_n >> 1, from_lwe_n))
+            .collect_vec();
+        let parties_to_lwe_sk = (0..no_of_parties)
+            .map(|_| LweSecret::random(to_lwe_n >> 1, to_lwe_n))
+            .collect_vec();
+
+        // Generate Lwe KSK share
+        let mut rng = DefaultSecureRng::new();
+        let mut ksk_seed = [0u8; 32];
+        rng.fill_bytes(&mut ksk_seed);
+        let lwe_ksk_shares =
+            izip!(parties_from_lwe_sk.iter(), parties_to_lwe_sk.iter()).map(|(from_sk, to_sk)| {
+                let mut ksk_out = vec![0u64; from_lwe_n * d_lwe];
+                let mut p_rng = DefaultSecureRng::new_seeded(ksk_seed);
+                lwe_ksk_keygen(
+                    from_sk.values(),
+                    to_sk.values(),
+                    &mut ksk_out,
+                    &lwe_gadgect_vec,
+                    &lweq_modop,
+                    &mut p_rng,
+                    &mut rng,
+                );
+                ksk_out
+            });
+
+        // Create collective LWE ksk
+        let mut sum_partb = vec![0u64; d_lwe * from_lwe_n];
+        lwe_ksk_shares.for_each(|share| {
+            lweq_modop.elwise_add_mut(sum_partb.as_mut_slice(), share.as_slice())
+        });
+        let mut lwe_ksk = vec![vec![0u64; to_lwe_n + 1]; d_lwe * from_lwe_n];
+        let mut p_rng = DefaultSecureRng::new_seeded(ksk_seed);
+        izip!(lwe_ksk.iter_mut(), sum_partb.iter()).for_each(|(lwe_i, part_bi)| {
+            RandomUniformDist::random_fill(&mut p_rng, &lwe_q, &mut lwe_i.as_mut_slice()[1..]);
+            lwe_i[0] = *part_bi;
+        });
+
+        // Collective pk
+        // let collective_pk = _collecitve_public_key_gen(
+        //     lwe_q,
+        //     &parties_from_lwe_sk
+        //         .iter()
+        //         .map(|s| RlweSecret {
+        //             values: s.values.clone(),
+        //         })
+        //         .collect_vec(),
+        // );
+
+        // // Encrypt m as LWE ciphertext
+        // let m = 1;
+        // let lwe_ct = {
+        //     let nttop = NttBackendU64::new(lwe_q, from_lwe_n);
+        //     let modop = ModularOpsU64::new(lwe_q);
+        //     let mut rlwe_out = vec![vec![0u64]; from_lwe_n];
+        //     let mut m_vec = vec![0u64; from_lwe_n];
+        //     m_vec[0] = m;
+        //     public_key_encrypt_rlwe(
+        //         &mut rlwe_out,
+        //         &collective_pk,
+        //         &m_vec,
+        //         &modop,
+        //         &nttop,
+        //         &mut rng,
+        //     );
+        //     let mut lwe_ct = vec![0u64; from_lwe_n + 1];
+        //     sample_extract(&mut lwe_ct, &rlwe_out, &modop, 0);
+        //     lwe_ct
+        // };
+        // Encrypt m
+        let m = 1;
+        let mut ideal_from_lwe_sk = vec![0i32; from_lwe_n];
+        parties_from_lwe_sk.iter().for_each(|k| {
+            izip!(ideal_from_lwe_sk.iter_mut(), k.values()).for_each(|(ideal_i, s_i)| {
+                *ideal_i = *ideal_i + s_i;
+            });
+        });
+        let mut lwe_ct = vec![0u64; from_lwe_n + 1];
+        encrypt_lwe(&mut lwe_ct, &m, &ideal_from_lwe_sk, &lweq_modop, &mut rng);
+
+        // Key switch
+        let lwe_ct_key_switched = {
+            let mut lwe_ct_key_switched = vec![0u64; to_lwe_n + 1];
+            let decomposer = DefaultDecomposer::new(lwe_q, logb_lwe, d_lwe);
+            lwe_key_switch(
+                &mut lwe_ct_key_switched,
+                &lwe_ct,
+                &lwe_ksk,
+                &lweq_modop,
+                &decomposer,
+            );
+            lwe_ct_key_switched
+        };
+
+        // Measure noise
+        let mut ideal_to_lwe_sk = vec![0i32; to_lwe_n];
+        parties_to_lwe_sk.iter().for_each(|k| {
+            izip!(ideal_to_lwe_sk.iter_mut(), k.values()).for_each(|(ideal_i, s_i)| {
+                *ideal_i = *ideal_i + s_i;
+            });
+        });
+        let noise = measure_noise_lwe(&lwe_ct_key_switched, &ideal_to_lwe_sk, &lweq_modop, &m);
+        println!("Noise: {noise}");
+    }
+
+    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);
+        RandomUniformDist::random_fill(&mut p_rng, &rlwe_q, pk_part_a.as_mut_slice());
+
+        vec![pk_part_a, pk_part_b]
+    }
+
+    fn _multi_party_keygen(
+        bool_evaluator: &BoolEvaluator<Vec<Vec<u64>>, u64, NttBackendU64, ModularOpsU64>,
+        no_of_parties: usize,
+    ) -> (
+        Vec<ClientKey>,
+        PublicKey<Vec<Vec<u64>>, DefaultSecureRng, ModularOpsU64>,
+        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();
@@ -1871,6 +2037,24 @@ mod tests {
             }
         };
 
+        (
+            parties,
+            collective_pk,
+            server_key_shares,
+            seeded_server_key,
+            server_key_eval,
+            ideal_client_key,
+        )
+    }
+
+    #[test]
+    fn mp_key_correcntess() {
+        let bool_evaluator =
+            BoolEvaluator::<Vec<Vec<u64>>, u64, NttBackendU64, ModularOpsU64>::new(MP_BOOL_PARAMS);
+
+        let (_, collective_pk, _, _, server_key_eval, ideal_client_key) =
+            _multi_party_keygen(&bool_evaluator, 2);
+
         let lwe_q = bool_evaluator.parameters.lwe_q;
         let rlwe_q = bool_evaluator.parameters.rlwe_q;
         let d_rgsw = bool_evaluator.parameters.d_rgsw;
@@ -1936,7 +2120,8 @@ mod tests {
 
             for i in 0..20 {
                 // measure noise in RGSW(s[i])
-                let si = ideal_client_key.sk_lwe.values[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;
@@ -1986,7 +2171,8 @@ mod tests {
                 );
 
                 // carry_m[X] * s_i[X]
-                let si = ideal_client_key.sk_lwe.values[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;
@@ -2067,11 +2253,11 @@ mod tests {
     }
 
     #[test]
-    fn trial12() {
+    fn multi_party_nand() {
         let bool_evaluator =
             BoolEvaluator::<Vec<Vec<u64>>, u64, NttBackendU64, ModularOpsU64>::new(MP_BOOL_PARAMS);
 
-        let no_of_parties = 2;
+        let no_of_parties = 20;
         let parties = (0..no_of_parties)
             .map(|_| bool_evaluator.client_key())
             .collect_vec();
@@ -2184,7 +2370,7 @@ mod tests {
 
             // let m_back = bool_evaluator.sk_decrypt(&lwe_out, &ideal_client_key);
 
-            assert_eq!(m_expected, m_back);
+            assert!(m_expected == m_back, "Expected {m_expected}, got {m_back}");
             m1 = m0;
             m0 = m_expected;
         }

src/bool/parameters.rs

@@ -38,16 +38,17 @@ pub(super) const SP_BOOL_PARAMS: BoolParameters = BoolParameters:: {
 };
 
 pub(super) const MP_BOOL_PARAMS: BoolParameters<u64> = BoolParameters::<u64> {
-    rlwe_q: 1152921504606830593,
-    rlwe_logq: 60,
-    lwe_q: 1 << 20,
-    lwe_logq: 20,
-    br_q: 1 << 12,
+    rlwe_q: 18014398509404161,
+    rlwe_logq: 54,
+    lwe_q: 1 << 18,
+    lwe_logq: 18,
+    // TODO(Jay:) why does this fail when q=1<<11?
+    br_q: 1 << 11,
     rlwe_n: 1 << 11,
-    lwe_n: 500,
-    d_rgsw: 10,
-    logb_rgsw: 6,
-    d_lwe: 5,
+    lwe_n: 200,
+    d_rgsw: 5,
+    logb_rgsw: 10,
+    d_lwe: 4,
     logb_lwe: 4,
     g: 5,
     w: 1,
@@ -59,7 +60,7 @@ mod tests {
 
     #[test]
     fn find_prime() {
-        let bits = 60;
+        let bits = 54;
         let ring_size = 1 << 11;
         let prime = generate_prime(bits, ring_size * 2, 1 << bits).unwrap();
         dbg!(prime);