From 8bf09baa551213b393227332c37ffdd59cad6cb5 Mon Sep 17 00:00:00 2001
From: Charles Gouert <cgouert@udel.edu>
Date: Thu, 7 Sep 2023 18:28:07 +0000
Subject: [PATCH] Update LBB

Co-authored-by: Dimitris Mouris <jimouris@udel.edu>
---
 src/circuit.rs | 4 ++--
 src/gates.rs   | 9 +++++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/circuit.rs b/src/circuit.rs
index 1c2f609..4786cf2 100644
--- a/src/circuit.rs
+++ b/src/circuit.rs
@@ -621,7 +621,7 @@ impl<'a> EvalCircuit<CtxtShortInt> for LutCircuit<'a> {
         {
             // Evaluate all the gates in the level in parallel
             gates.par_iter_mut().for_each(|gate| {
-                let input_values: Vec<CtxtShortInt> = gate
+                let mut input_values: Vec<CtxtShortInt> = gate
                     .get_input_wires()
                     .iter()
                     .map(|input| {
@@ -637,7 +637,7 @@ impl<'a> EvalCircuit<CtxtShortInt> for LutCircuit<'a> {
                     .collect();
                 let output_value = {
                     if gate.get_gate_type() == GateType::Lut {
-                        gate.evaluate_encrypted_lut(&self.server_key, &input_values, cycle)
+                        gate.evaluate_encrypted_lut(&self.server_key, &mut input_values, cycle)
                     } else {
                         gate.evaluate_encrypted_dff(&input_values, cycle)
                     }
diff --git a/src/gates.rs b/src/gates.rs
index 0afaa80..dcd5fce 100644
--- a/src/gates.rs
+++ b/src/gates.rs
@@ -278,7 +278,7 @@ impl Gate {
     pub fn evaluate_encrypted_lut(
         &mut self,
         server_key: &ServerKeyShortInt,
-        input_values: &Vec<CiphertextBase>,
+        input_values: &mut Vec<CiphertextBase>,
         cycle: usize,
     ) -> CiphertextBase {
         if let Some(encrypted_lut_output) = self.encrypted_lut_output.clone() {
@@ -744,13 +744,14 @@ fn eval_luts(x: u64, lut_table: &Vec<u64>) -> u64 {
 pub fn lut(
     sks: &ServerKeyShortInt,
     lut_const: &Vec<u64>,
-    ctxts: &Vec<CiphertextBase>,
+    ctxts: &mut Vec<CiphertextBase>,
 ) -> CiphertextBase {
     // Σ ctxts[i] * 2^i
+    let ctxts_len = (ctxts.len() - 1) as u8;
     let ct_sum = ctxts
-        .iter()
+        .iter_mut()
         .enumerate()
-        .map(|(i, ct)| sks.scalar_mul(ct, 1 << (ctxts.len() - 1 - i)))
+        .map(|(i, ct)| sks.smart_scalar_left_shift(ct, ctxts_len - i as u8))
         .fold(sks.create_trivial(0), |acc, ct| sks.add(&acc, &ct));
 
     // Generate LUT entries from lut_const