From f192f29a862c536c75876dad875b9366268527e5 Mon Sep 17 00:00:00 2001
From: Sam Hadow <sam.hadow@inbox.lv>
Date: Sat, 24 May 2025 00:30:39 +0200
Subject: [PATCH] integrate in agcd

---
 src/agcd.rs     | 31 +++++++++++++++++++------------
 src/deep_lll.rs | 12 +++++++++---
 2 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/src/agcd.rs b/src/agcd.rs
index f655507..6a67977 100644
--- a/src/agcd.rs
+++ b/src/agcd.rs
@@ -1,29 +1,36 @@
 use crate::bkz::bkz_reduce;
+use crate::deep_lll::deep_lll;
 use crate::matrix::Matrix;
 use crate::utils::abs;
 use lll_rs::l2::bigl2;
-use rug::Integer;
+use rug::{Integer, Rational};
 
 pub fn agcd(ciphertexts: Vec<Integer>, noise_bits: usize, algorithm: u8) -> Integer {
     // 1. Build lattice matrix basis
     let basis_matrix = Matrix::new_lattice(noise_bits, ciphertexts.clone()).unwrap();
 
-    // 2. reduce with LLL
+    // 2. reduce with LLL, and extract first element of shortest vector
     let mut lll_matrix = basis_matrix.to_lll_matrix();
     println!("basis: {:?}", lll_matrix);
-    match algorithm {
-        0u8 => bigl2::lattice_reduce(&mut lll_matrix, 0.51, 0.75),
-        1u8 => bkz_reduce(&mut lll_matrix, 16, 0.75, 0.75, 10),
-        _ => panic!(),
-    }
-    println!("basis after reduction: {:?}", lll_matrix);
 
-    // 3. Extract shortest vector
-    let shortest_vector = &lll_matrix[0];
-    println!("Shortest vector: {:?}", shortest_vector);
+    let first_elem = match algorithm {
+        0u8 => {
+            bigl2::lattice_reduce(&mut lll_matrix, 0.51, 0.75);
+            lll_matrix[0][0].clone()
+        }
+        1u8 => {
+            bkz_reduce(&mut lll_matrix, 16, 0.75, 0.75, 10);
+            lll_matrix[0][0].clone()
+        }
+        2u8 => {
+            let reduced = deep_lll(basis_matrix.clone(), Rational::from((51, 100))).unwrap();
+            reduced.columns[0][0].clone()
+        }
+        _ => panic!("Unknown algorithm value: {}", algorithm),
+    };
 
     // 4. q0 candidate
-    let q0 = &shortest_vector[0] / (Integer::from(1) << (noise_bits + 1));
+    let q0 = first_elem / (Integer::from(1) << (noise_bits + 1));
     println!("q0: {}", q0);
 
     if q0 == 0 {
diff --git a/src/deep_lll.rs b/src/deep_lll.rs
index 3a6da05..e85a14b 100644
--- a/src/deep_lll.rs
+++ b/src/deep_lll.rs
@@ -1,5 +1,5 @@
 use crate::matrix::Matrix;
-use rug::{Integer, Rational};
+use rug::Rational;
 
 /// Perform DeepLLL reduction on a given lattice basis represented by Matrix.
 /// 1/4 < delta < 1.
@@ -7,11 +7,19 @@ pub fn deep_lll(mut mat: Matrix, delta: Rational) -> Option<Matrix> {
     let n = mat.n;
     let (mut mu, mut b_star_sq) = gramm_schmidt(&mat);
     let mut k = 2;
+    let mut iterations = 0;
+    const MAX_ITERATIONS: usize = 100;
 
     while k <= n {
+        if iterations >= MAX_ITERATIONS {
+            eprintln!("Warning: DeepLLL did not converge after {} iterations", MAX_ITERATIONS);
+            return Some(mat);
+        }
+        iterations += 1;
         size_reduce(&mut mat, &mut mu, &mut b_star_sq, k);
         let mut c = norm_sq(&mat, k);
         let mut i = 1;
+        dbg!(&mat);
         while i < k {
             if c >= delta.clone() * b_star_sq[i - 1].clone() {
                 let mu_ki = mu[k - 1][i - 1].clone();
@@ -26,10 +34,8 @@ pub fn deep_lll(mut mat: Matrix, delta: Rational) -> Option<Matrix> {
                 break;
             }
         }
-
         k += 1;
     }
-
     Some(mat)
 }