@@ -26,3 +26,12 @@
 [[bench]]
 name = "modulus"
 harness = false
+
+[[example]]
+name = "interactive_fheuint8"
+path = "./examples/interactive_fheuint8.rs"
+
+[[example]]
+name = "non_interactive_fheuint8"
+path = "./examples/non_interactive_fheuint8.rs"
+required-features = ["non_interactive_mp"]

@@ -6,13 +6,13 @@ fn plain_circuit(a: u8, b: u8, c: u8) -> u8 {
     (a + b) * c
 }
 
-// fn fhe_circuit(fhe_a: &FheUint8, fhe_b: &FheUint8, fhe_c: &FheUint8) ->
-// FheUint8 {     &(fhe_a + fhe_b) * fhe_c
-// }
+fn fhe_circuit(fhe_a: &FheUint8, fhe_b: &FheUint8, fhe_c: &FheUint8) -> FheUint8 {
+    &(fhe_a + fhe_b) * fhe_c
+}
 
 fn main() {
     set_parameter_set(ParameterSelector::MultiPartyLessThanOrEqualTo16);
-    let no_of_parties = 2;
+    let no_of_parties = 8;
     let client_keys = (0..no_of_parties)
         .into_iter()
         .map(|_| gen_client_key())
@@ -50,25 +50,22 @@ let fhe_a = public_key.encrypt(&a);
     let fhe_b = public_key.encrypt(&b);
     let fhe_c = public_key.encrypt(&c);
 
-    let fhe_batched = public_key.encrypt(vec![12, 3u8].as_slice());
-
     // fhe evaluation
-    // let now = std::time::Instant::now();
-    // let fhe_out = fhe_circuit(&fhe_a, &fhe_b, &fhe_c);
-    // println!("Circuit time: {:?}", now.elapsed());
+    let now = std::time::Instant::now();
+    let fhe_out = fhe_circuit(&fhe_a, &fhe_b, &fhe_c);
+    println!("Circuit time: {:?}", now.elapsed());
 
-    // // plain evaluation
-    // let out = plain_circuit(a, b, c);
+    // plain evaluation
+    let out = plain_circuit(a, b, c);
 
-    // // generate decryption shares to decrypt ciphertext fhe_out
-    // let decryption_shares = client_keys
-    //     .iter()
-    //     .map(|k| k.gen_decryption_share(&fhe_out))
-    //     .collect_vec();
+    // generate decryption shares to decrypt ciphertext fhe_out
+    let decryption_shares = client_keys
+        .iter()
+        .map(|k| k.gen_decryption_share(&fhe_out))
+        .collect_vec();
 
-    // // decrypt fhe_out using decryption shares
-    // let got_out = client_keys[0].aggregate_decryption_shares(&fhe_out,
-    // &decryption_shares);
+    // decrypt fhe_out using decryption shares
+    let got_out = client_keys[0].aggregate_decryption_shares(&fhe_out, &decryption_shares);
 
-    // assert_eq!(got_out, out);
+    assert_eq!(got_out, out);
 }

@@ -0,0 +1,73 @@
+use bin_rs::*;
+use itertools::Itertools;
+use rand::{thread_rng, Rng, RngCore};
+
+fn circuit(a: u8, b: u8, c: u8, d: u8) -> u8 {
+    ((a + b) * c) * d
+}
+
+fn fhe_circuit(a: &FheUint8, b: &FheUint8, c: &FheUint8, d: &FheUint8) -> FheUint8 {
+    &(&(a + b) * c) * d
+}
+
+fn main() {
+    set_parameter_set(ParameterSelector::NonInteractiveMultiPartyLessThanOrEqualTo16);
+
+    // set CRS
+    let mut seed = [0u8; 32];
+    thread_rng().fill_bytes(&mut seed);
+    set_common_reference_seed(seed);
+
+    let no_of_parties = 2;
+
+    // Generate client keys
+    let cks = (0..no_of_parties).map(|_| gen_client_key()).collect_vec();
+
+    // client 0 encrypts private input
+    let c0_a = thread_rng().gen::<u8>();
+    let c0_b = thread_rng().gen::<u8>();
+    let c0_batched_to_send = cks[0].encrypt(vec![c0_a, c0_b].as_slice());
+
+    // client 1 encrypts private input
+    let c1_a = thread_rng().gen::<u8>();
+    let c1_b = thread_rng().gen::<u8>();
+    let c1_batch_to_send = cks[1].encrypt(vec![c1_a, c1_b].as_slice());
+
+    // Both client indenpendently generate their server key shares
+    let server_key_shares = cks
+        .iter()
+        .enumerate()
+        .map(|(id, k)| gen_server_key_share(id, no_of_parties, k))
+        .collect_vec();
+
+    // Server side
+
+    // aggregates shares and generates server key
+    let server_key = aggregate_server_key_shares(&server_key_shares);
+    server_key.set_server_key();
+
+    // extract a and b from client0 inputs
+    let (ct_c0_a, ct_c0_b) = {
+        let ct = c0_batched_to_send.unseed::<Vec<Vec<u64>>>().key_switch(0);
+        (ct.extract(0), ct.extract(1))
+    };
+
+    // extract a and b from client1 inputs
+    let (ct_c1_a, ct_c1_b) = {
+        let ct = c1_batch_to_send.unseed::<Vec<Vec<u64>>>().key_switch(1);
+        (ct.extract(0), ct.extract(1))
+    };
+
+    let now = std::time::Instant::now();
+    let c_out = fhe_circuit(&ct_c0_a, &ct_c1_a, &ct_c0_b, &ct_c1_b);
+    println!("Circuit Time: {:?}", now.elapsed());
+
+    // decrypt c_out
+    let decryption_shares = cks
+        .iter()
+        .map(|k| k.gen_decryption_share(&c_out))
+        .collect_vec();
+    let m_out = cks[0].aggregate_decryption_shares(&c_out, &decryption_shares);
+    let m_expected = circuit(c0_a, c1_a, c0_b, c1_b);
+    assert!(m_expected == m_out);
+}

@@ -1,16 +1,21 @@
 pub(crate) mod evaluator;
 mod keys;
-mod mp_api;
-mod ni_mp_api;
 mod noise;
 pub(crate) mod parameters;
 
 pub(crate) use keys::PublicKey;
+
+#[cfg(feature = "interactive_mp")]
+#[cfg(not(feature = "non_interactive_mp"))]
+mod mp_api;
+#[cfg(feature = "non_interactive_mp")]
+mod ni_mp_api;
 
 #[cfg(feature = "non_interactive_mp")]
 pub use ni_mp_api::*;
 
 #[cfg(feature = "interactive_mp")]
+#[cfg(not(feature = "non_interactive_mp"))]
 pub use mp_api::*;
 
 pub type ClientKey = keys::ClientKey<[u8; 32], u64>;
@@ -22,7 +27,11 @@ }
 
 mod common_mp_enc_dec {
     use super::BoolEvaluator;
-    use crate::{utils::WithLocal, Matrix, MultiPartyDecryptor};
+    use crate::{
+        pbs::{sample_extract, PbsInfo},
+        utils::WithLocal,
+        Matrix, MultiPartyDecryptor, RowEntity, SampleExtractor,
+    };
 
     type Mat = Vec<Vec<u64>>;
 
@@ -39,6 +48,22 @@ c: &<Mat as Matrix>::R,
             shares: &[Self::DecryptionShare],
         ) -> bool {
             BoolEvaluator::with_local(|e| e.multi_party_decrypt(shares, c))
+        }
+    }
+
+    impl SampleExtractor<<Mat as Matrix>::R> for Mat {
+        fn extract(&self, index: usize) -> <Mat as Matrix>::R {
+            // input is RLWE ciphertext
+            assert!(self.dimension().0 == 2);
+
+            let ring_size = self.dimension().1;
+            assert!(index < ring_size);
+
+            BoolEvaluator::with_local(|e| {
+                let mut lwe_out = <Mat as Matrix>::R::zeros(ring_size + 1);
+                sample_extract(&mut lwe_out, self, e.pbs_info().modop_rlweq(), index);
+                lwe_out
+            })
         }
     }
 }

@@ -9,7 +9,7 @@ };
 
 use super::{evaluator::MultiPartyCrs, keys::*, parameters::*, ClientKey, ParameterSelector};
 
-pub type BoolEvaluator = super::evaluator::BoolEvaluator<
+pub(crate) type BoolEvaluator = super::evaluator::BoolEvaluator<
     Vec<Vec<u64>>,
     NttBackendU64,
     ModularOpsU64<CiphertextModulus<u64>>,
@@ -304,8 +304,13 @@ }
     }
 
     mod sp_api {
+        use num_traits::ToPrimitive;
+        use rand::Rng;
+
         use crate::{
-            backend::ModulusPowerOf2, utils::WithLocal, Decryptor, ModularOpsU64, NttBackendU64,
+            backend::ModulusPowerOf2, evaluator::BoolEncoding, pbs::PbsInfo,
+            rgsw::secret_key_encrypt_rlwe, utils::WithLocal, Decryptor, ModularOpsU64,
+            NttBackendU64, SampleExtractor,
         };
 
         use super::*;
@@ -357,6 +362,86 @@ impl<K: SinglePartyClientKey<Element = i32>> Decryptor<bool, Vec<u64>> for K {
             fn decrypt(&self, c: &Vec<u64>) -> bool {
                 BoolEvaluator::with_local(|e| e.sk_decrypt(c, self))
             }
+        }
+        impl<K> Encryptor<[bool], (Vec<Vec<u64>>, [u8; 32])> for K
+        where
+            K: SinglePartyClientKey<Element = i32>,
+        {
+            fn encrypt(&self, m: &[bool]) -> (Vec<Vec<u64>>, [u8; 32]) {
+                BoolEvaluator::with_local(|e| {
+                    DefaultSecureRng::with_local_mut(|rng| {
+                        let parameters = e.parameters();
+                        let ring_size = parameters.rlwe_n().0;
+
+                        let rlwe_count = ((m.len() as f64 / ring_size as f64).ceil())
+                            .to_usize()
+                            .unwrap();
+
+                        let mut seed = <DefaultSecureRng as NewWithSeed>::Seed::default();
+                        rng.fill_bytes(&mut seed);
+                        let mut prng = DefaultSecureRng::new_seeded(seed);
+
+                        let sk_u = self.sk_rlwe();
+
+                        // encrypt `m` into ceil(len(m)/N) RLWE ciphertexts
+                        let rlwes = (0..rlwe_count)
+                            .map(|index| {
+                                let mut message = vec![0; ring_size];
+                                m[(index * ring_size)
+                                    ..std::cmp::min(m.len(), (index + 1) * ring_size)]
+                                    .iter()
+                                    .enumerate()
+                                    .for_each(|(i, v)| {
+                                        if *v {
+                                            message[i] = parameters.rlwe_q().true_el()
+                                        } else {
+                                            message[i] = parameters.rlwe_q().false_el()
+                                        }
+                                    });
+
+                                // encrypt message
+                                let mut rlwe_out = vec![0u64; parameters.rlwe_n().0];
+
+                                secret_key_encrypt_rlwe(
+                                    &message,
+                                    &mut rlwe_out,
+                                    &sk_u,
+                                    e.pbs_info().modop_rlweq(),
+                                    e.pbs_info().nttop_rlweq(),
+                                    &mut prng,
+                                    rng,
+                                );
+
+                                rlwe_out
+                            })
+                            .collect_vec();
+
+                        (rlwes, seed)
+                    })
+                })
+            }
+        }
+
+        #[test]
+        fn batch_extract_works() {
+            set_single_party_parameter_sets(SP_TEST_BOOL_PARAMS);
+
+            let (ck, sk) = gen_keys();
+            sk.set_server_key();
+
+            let batch_size = (SP_TEST_BOOL_PARAMS.rlwe_n().0 * 3 + 123);
+            let m = (0..batch_size)
+                .map(|_| thread_rng().gen::<u8>())
+                .collect_vec();
+
+            let seeded_ct = ck.encrypt(m.as_slice());
+            let ct = seeded_ct.unseed::<Vec<Vec<u64>>>();
+
+            let m_back = (0..batch_size)
+                .map(|i| ck.decrypt(&ct.extract(i)))
+                .collect_vec();
+
+            assert_eq!(m, m_back);
         }
 
         #[test]

@@ -19,7 +19,7 @@ parameters::{BoolParameters, CiphertextModulus, NON_INTERACTIVE_SMALL_MP_BOOL_PARAMS},
     ClientKey, ParameterSelector,
 };
 
-pub type BoolEvaluator = super::evaluator::BoolEvaluator<
+pub(crate) type BoolEvaluator = super::evaluator::BoolEvaluator<
     Vec<Vec<u64>>,
     NttBackendU64,
     ModularOpsU64<CiphertextModulus<u64>>,

@@ -23,8 +23,10 @@ // pub use bool::{
 //     aggregate_public_key_shares, aggregate_server_key_shares, gen_client_key,
 // gen_mp_keys_phase1,     gen_mp_keys_phase2, set_mp_seed, set_parameter_set,
 // ParameterSelector, };
+pub use bool::*;
 pub use decomposer::{Decomposer, DecomposerIter, DefaultDecomposer};
 pub use ntt::{Ntt, NttBackendU64, NttInit};
+pub use shortint::FheUint8;
 
 pub trait Matrix: AsRef<[Self::R]> {
     type MatElement;
@@ -184,6 +186,10 @@ pub trait KeySwitchWithId<C> {
     fn key_switch(&self, user_id: usize) -> C;
 }
 
-pub(crate) trait Encoder<F, T> {
+pub trait SampleExtractor<R> {
+    fn extract(&self, index: usize) -> R;
+}
+
+trait Encoder<F, T> {
     fn encode(&self, v: F) -> T;
 }

@@ -5,9 +5,13 @@ bool::BoolEvaluator,
     random::{DefaultSecureRng, RandomFillUniformInModulus},
     utils::{TryConvertFrom1, WithLocal},
     Decryptor, Encryptor, KeySwitchWithId, Matrix, MatrixEntity, MatrixMut, MultiPartyDecryptor,
-    RowMut,
+    RowMut, SampleExtractor,
 };
 
+/// Fhe UInt8 type
+///
+/// - Stores encryptions of bits in little endian (i.e least signficant bit
+///   stored at 0th index and most signficant bit stores at 7th index)
 #[derive(Clone)]
 pub struct FheUint8<C> {
     pub(super) data: Vec<C>,
@@ -25,6 +29,28 @@ }
 
 pub struct BatchedFheUint8<C> {
     data: Vec<C>,
+}
+
+impl<C, R> SampleExtractor<FheUint8<R>> for BatchedFheUint8<C>
+where
+    C: SampleExtractor<R>,
+{
+    fn extract(&self, index: usize) -> FheUint8<R> {
+        BoolEvaluator::with_local(|e| {
+            let ring_size = e.parameters().rlwe_n().0;
+
+            let start_index = index * 8;
+            let end_index = (index + 1) * 8;
+            let data = (start_index..end_index)
+                .map(|i| {
+                    let rlwe_index = i / ring_size;
+                    let coeff_index = i % ring_size;
+                    self.data[rlwe_index].extract(coeff_index)
+                })
+                .collect_vec();
+            FheUint8 { data }
+        })
+    }
 }
 
 impl<M: MatrixEntity + MatrixMut<MatElement = u64>> From<&SeededBatchedFheUint8<M::R, [u8; 32]>>
@@ -85,7 +111,6 @@ .iter()
             .flat_map(|v| (0..8).into_iter().map(|i| (((*v) >> i) & 1) == 1))
             .collect_vec();
         let (cts, seed) = K::encrypt(&self, &m);
-        dbg!(cts.len());
         SeededBatchedFheUint8 { data: cts, seed }
     }
 }