diff --git a/base2k/src/vec_znx_big.rs b/base2k/src/vec_znx_big.rs
index a7bdd59..e1f656f 100644
--- a/base2k/src/vec_znx_big.rs
+++ b/base2k/src/vec_znx_big.rs
@@ -12,6 +12,25 @@ pub struct VecZnxBig<B: Backend> {
 }
 
 impl VecZnxBig<FFT64> {
+
+    pub fn new(module: &Module<FFT64>, cols: usize, limbs: usize) -> Self {
+        #[cfg(debug_assertions)]
+        {
+            assert!(cols > 0);
+            assert!(limbs > 0);
+        }
+        let mut data: Vec<u8> = alloc_aligned::<u8>(module.bytes_of_vec_znx_big(cols, limbs));
+        let ptr: *mut u8 = data.as_mut_ptr();
+        Self {
+            data: data,
+            ptr: ptr,
+            n: module.n(),
+            cols: cols,
+            limbs: limbs,
+            _marker: PhantomData,
+        }
+    }
+
     /// Returns a new [VecZnxBig] with the provided data as backing array.
     /// User must ensure that data is properly alligned and that
     /// the size of data is at least equal to [Module::bytes_of_vec_znx_big].
@@ -64,22 +83,74 @@ impl VecZnxBig<FFT64> {
         }
     }
 
-    /// Returns a non-mutable reference to the entire contiguous array of the [VecZnxDft].
-    pub fn raw(&self) -> &[i64] {
-        let ptr: *const i64 = self.ptr as *const i64;
-        unsafe { &std::slice::from_raw_parts(ptr, self.n() * self.poly_count()) }
+    /// Returns a non-mutable pointer to the backedn slice of the receiver.
+    pub fn as_ptr(&self) -> *const i64 {
+        self.ptr as *const i64
+    }
+
+    /// Returns a mutable pointer to the backedn slice of the receiver.
+    pub fn as_mut_ptr(&mut self) -> *mut i64 {
+        self.ptr as *mut i64
+    }
+
+    pub fn raw(&self) -> &[i64] {
+        unsafe { &std::slice::from_raw_parts(self.as_ptr(), self.n() * self.poly_count()) }
+    }
+
+    pub fn raw_mut(&mut self) -> &mut [i64] {
+        let ptr: *mut i64 = self.ptr as *mut i64;
+        let size: usize = self.n() * self.poly_count();
+        unsafe { std::slice::from_raw_parts_mut(ptr, size) }
+    }
+
+    pub fn at_ptr(&self, i: usize, j: usize) -> *const i64 {
+        #[cfg(debug_assertions)]
+        {
+            assert!(i < self.cols());
+            assert!(j < self.limbs());
+        }
+        let offset: usize = self.n * (j * self.cols() + i);
+        self.as_ptr().wrapping_add(offset)
+    }
+
+    /// Returns a non-mutable reference to the i-th limb.
+    /// The returned array is of size [Self::n()] * [Self::cols()].
+    pub fn at_limb(&self, i: usize) -> &[i64] {
+        unsafe { std::slice::from_raw_parts(self.at_ptr(0, i), self.n * self.cols()) }
+    }
+
+    /// Returns a non-mutable reference to the (i, j)-th poly.
+    /// The returned array is of size [Self::n()].
+    pub fn at_poly(&self, i: usize, j: usize) -> &[i64] {
+        unsafe { std::slice::from_raw_parts(self.at_ptr(i, j), self.n) }
+    }
+
+    /// Returns a mutable pointer starting a the (i, j)-th small poly.
+    pub fn at_mut_ptr(&mut self, i: usize, j: usize) -> *mut i64 {
+        #[cfg(debug_assertions)]
+        {
+            assert!(i < self.cols());
+            assert!(j < self.limbs());
+        }
+
+        let offset: usize = self.n * (j * self.cols() + i);
+        self.as_mut_ptr().wrapping_add(offset)
+    }
+
+    /// Returns a mutable reference to the i-th limb.
+    /// The returned array is of size [Self::n()] * [Self::cols()].
+    pub fn at_limb_mut(&mut self, i: usize) -> &mut [i64] {
+        unsafe { std::slice::from_raw_parts_mut(self.at_mut_ptr(0, i), self.n * self.cols()) }
+    }
+
+    /// Returns a mutable reference to the (i, j)-th poly.
+    /// The returned array is of size [Self::n()].
+    pub fn at_poly_mut(&mut self, i: usize, j: usize) -> &mut [i64] {
+        unsafe { std::slice::from_raw_parts_mut(self.at_mut_ptr(i, j), self.n) }
     }
 
-    // Prints the first `n` coefficients of each limb
     pub fn print(&self, n: usize) {
-        let raw: &[i64] = self.raw();
-        (0..self.limbs()).for_each(|i| {
-            println!(
-                "{}: {:?}",
-                i,
-                &raw[i * self.n() * self.cols()..i * self.n() * self.cols() + n]
-            )
-        })
+        (0..self.limbs()).for_each(|i| println!("{}: {:?}", i, &self.at_limb(i)[..n]));
     }
 }
 
@@ -192,21 +263,7 @@ pub trait VecZnxBigOps<B: Backend> {
 
 impl VecZnxBigOps<FFT64> for Module<FFT64> {
     fn new_vec_znx_big(&self, cols: usize, limbs: usize) -> VecZnxBig<FFT64> {
-        #[cfg(debug_assertions)]
-        {
-            assert!(cols > 0);
-            assert!(limbs > 0);
-        }
-        let mut data: Vec<u8> = alloc_aligned::<u8>(self.bytes_of_vec_znx_big(cols, limbs));
-        let ptr: *mut u8 = data.as_mut_ptr();
-        VecZnxBig::<FFT64> {
-            data: data,
-            ptr: ptr,
-            n: self.n(),
-            cols: cols,
-            limbs: limbs,
-            _marker: PhantomData,
-        }
+        VecZnxBig::new(self, cols, limbs)
     }
 
     fn new_vec_znx_big_from_bytes(&self, cols: usize, limbs: usize, bytes: &mut [u8]) -> VecZnxBig<FFT64> {
diff --git a/base2k/src/vec_znx_dft.rs b/base2k/src/vec_znx_dft.rs
index 61c2a85..d984cdd 100644
--- a/base2k/src/vec_znx_dft.rs
+++ b/base2k/src/vec_znx_dft.rs
@@ -16,6 +16,11 @@ pub struct VecZnxDft<B: Backend> {
 
 impl VecZnxDft<FFT64> {
     pub fn new(module: &Module<FFT64>, cols: usize, limbs: usize) -> Self {
+        #[cfg(debug_assertions)]
+        {
+            assert!(cols > 0);
+            assert!(limbs > 0);
+        }
         let mut data: Vec<u8> = alloc_aligned::<u8>(module.bytes_of_vec_znx_dft(cols, limbs));
         let ptr: *mut u8 = data.as_mut_ptr();
         Self {