diff --git a/base2k/src/vec_znx.rs b/base2k/src/vec_znx.rs
index 13c0bca..540d120 100644
--- a/base2k/src/vec_znx.rs
+++ b/base2k/src/vec_znx.rs
@@ -12,7 +12,7 @@ pub trait VecZnxVec {
     fn dblptr_mut(&mut self) -> Vec<&mut [i64]>;
 }
 
-impl<T: VecZnxApi + Infos> VecZnxVec for Vec<T> {
+impl<T: VecZnxCommon> VecZnxVec for Vec<T> {
     fn dblptr(&self) -> Vec<&[i64]> {
         self.iter().map(|v| v.raw()).collect()
     }
@@ -23,7 +23,7 @@ impl<T: VecZnxApi + Infos> VecZnxVec for Vec<T> {
 }
 
 pub trait VecZnxApi: AsRef<Self> + AsMut<Self> {
-    type Owned: VecZnxApi + Infos;
+    type Owned: VecZnxCommon;
 
     fn from_bytes(n: usize, cols: usize, bytes: &mut [u8]) -> Self::Owned;
 
@@ -32,9 +32,9 @@ pub trait VecZnxApi: AsRef<Self> + AsMut<Self> {
     fn bytes_of(n: usize, cols: usize) -> usize;
 
     /// Copy the data of a onto self.
-    fn copy_from<T: VecZnxApi + Infos>(&mut self, a: &T)
+    fn copy_from<A: VecZnxCommon, B: VecZnxCommon>(&mut self, a: &A)
     where
-        Self: AsMut<T>;
+        Self: AsMut<B>;
 
     /// Returns the backing array.
     fn raw(&self) -> &[i64];
@@ -86,9 +86,9 @@ pub trait VecZnxApi: AsRef<Self> + AsMut<Self> {
     /// # Arguments
     ///
     /// * `a`: the receiver polynomial in which the extracted coefficients are stored.
-    fn switch_degree<T: VecZnxApi + Infos>(&self, a: &mut T)
+    fn switch_degree<A: VecZnxCommon, B: VecZnxCommon>(&self, a: &mut A)
     where
-        Self: AsRef<T>;
+        Self: AsRef<B>;
 
     fn print(&self, cols: usize, n: usize);
 }
@@ -115,6 +115,8 @@ impl AsRef<VecZnxBorrow> for VecZnxBorrow {
     }
 }
 
+impl VecZnxCommon for VecZnxBorrow {}
+
 impl VecZnxApi for VecZnxBorrow {
     type Owned = VecZnxBorrow;
 
@@ -145,11 +147,11 @@ impl VecZnxApi for VecZnxBorrow {
         bytes_of_vec_znx(n, cols)
     }
 
-    fn copy_from<T: VecZnxApi + Infos>(&mut self, a: &T)
+    fn copy_from<A: VecZnxCommon, B: VecZnxCommon>(&mut self, a: &A)
     where
-        Self: AsMut<T>,
+        Self: AsMut<B>,
     {
-        copy_vec_znx_from::<T>(self.as_mut(), a);
+        copy_vec_znx_from::<A, B>(self.as_mut(), a);
     }
 
     fn as_ptr(&self) -> *const i64 {
@@ -200,9 +202,9 @@ impl VecZnxApi for VecZnxBorrow {
         rsh(log_base2k, self, k, carry)
     }
 
-    fn switch_degree<T: VecZnxApi + Infos>(&self, a: &mut T)
+    fn switch_degree<A: VecZnxCommon, B: VecZnxCommon>(&self, a: &mut A)
     where
-        Self: AsRef<T>,
+        Self: AsRef<B>,
     {
         switch_degree(a, self.as_ref());
     }
@@ -212,6 +214,8 @@ impl VecZnxApi for VecZnxBorrow {
     }
 }
 
+impl VecZnxCommon for VecZnx {}
+
 impl VecZnxApi for VecZnx {
     type Owned = VecZnx;
 
@@ -242,9 +246,9 @@ impl VecZnxApi for VecZnx {
         bytes_of_vec_znx(n, cols)
     }
 
-    fn copy_from<T: VecZnxApi + Infos>(&mut self, a: &T)
+    fn copy_from<A: VecZnxCommon, B: VecZnxCommon>(&mut self, a: &A)
     where
-        Self: AsMut<T>,
+        Self: AsMut<B>,
     {
         copy_vec_znx_from(self.as_mut(), a);
     }
@@ -295,9 +299,9 @@ impl VecZnxApi for VecZnx {
         rsh(log_base2k, self, k, carry)
     }
 
-    fn switch_degree<T: VecZnxApi + Infos>(&self, a: &mut T)
+    fn switch_degree<A: VecZnxCommon, B: VecZnxCommon>(&self, a: &mut A)
     where
-        Self: AsRef<T>,
+        Self: AsRef<B>,
     {
         switch_degree(a, self.as_ref())
     }
@@ -332,7 +336,7 @@ impl AsRef<VecZnx> for VecZnx {
 
 /// Copies the coefficients of `a` on the receiver.
 /// Copy is done with the minimum size matching both backing arrays.
-pub fn copy_vec_znx_from<T: VecZnxApi + Infos>(b: &mut T, a: &T) {
+pub fn copy_vec_znx_from<A: VecZnxCommon, B: VecZnxCommon>(b: &mut B, a: &A) {
     let data_a: &[i64] = a.raw();
     let data_b: &mut [i64] = b.raw_mut();
     let size = min(data_b.len(), data_a.len());
@@ -373,7 +377,7 @@ impl VecZnx {
     }
 }
 
-pub fn switch_degree<T: VecZnxApi + Infos>(b: &mut T, a: &T) {
+pub fn switch_degree<A: VecZnxCommon, B: VecZnxCommon>(b: &mut B, a: &A) {
     let (n_in, n_out) = (a.n(), b.n());
     let (gap_in, gap_out): (usize, usize);
 
@@ -395,7 +399,7 @@ pub fn switch_degree<T: VecZnxApi + Infos>(b: &mut T, a: &T) {
     });
 }
 
-fn normalize<T: VecZnxApi + Infos>(log_base2k: usize, a: &mut T, carry: &mut [u8]) {
+fn normalize<T: VecZnxCommon>(log_base2k: usize, a: &mut T, carry: &mut [u8]) {
     let n: usize = a.n();
 
     assert!(
@@ -422,7 +426,7 @@ fn normalize<T: VecZnxApi + Infos>(log_base2k: usize, a: &mut T, carry: &mut [u8
     }
 }
 
-pub fn rsh<T: VecZnxApi + Infos>(log_base2k: usize, a: &mut T, k: usize, carry: &mut [u8]) {
+pub fn rsh<T: VecZnxCommon>(log_base2k: usize, a: &mut T, k: usize, carry: &mut [u8]) {
     let n: usize = a.n();
 
     assert!(
@@ -462,6 +466,8 @@ pub fn rsh<T: VecZnxApi + Infos>(log_base2k: usize, a: &mut T, k: usize, carry:
     }
 }
 
+pub trait VecZnxCommon: VecZnxApi + Infos {}
+
 pub trait VecZnxOps {
     /// Allocates a new [VecZnx].
     ///
@@ -475,34 +481,50 @@ pub trait VecZnxOps {
     fn bytes_of_vec_znx(&self, cols: usize) -> usize;
 
     /// c <- a + b.
-    fn vec_znx_add<T: VecZnxApi + Infos>(&self, c: &mut T, a: &T, b: &T);
+    fn vec_znx_add<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        c: &mut C,
+        a: &A,
+        b: &B,
+    );
 
     /// b <- b + a.
-    fn vec_znx_add_inplace<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T);
+    fn vec_znx_add_inplace<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A);
 
     /// c <- a - b.
-    fn vec_znx_sub<T: VecZnxApi + Infos>(&self, c: &mut T, a: &T, b: &T);
+    fn vec_znx_sub<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        c: &mut C,
+        a: &A,
+        b: &B,
+    );
 
     /// b <- b - a.
-    fn vec_znx_sub_inplace<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T);
+    fn vec_znx_sub_inplace<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A);
 
     /// b <- -a.
-    fn vec_znx_negate<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T);
+    fn vec_znx_negate<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A);
 
     /// b <- -b.
-    fn vec_znx_negate_inplace<T: VecZnxApi + Infos>(&self, a: &mut T);
+    fn vec_znx_negate_inplace<A: VecZnxCommon>(&self, a: &mut A);
 
     /// b <- a * X^k (mod X^{n} + 1)
-    fn vec_znx_rotate<T: VecZnxApi + Infos>(&self, k: i64, b: &mut T, a: &T);
+    fn vec_znx_rotate<A: VecZnxCommon, B: VecZnxCommon>(&self, k: i64, b: &mut B, a: &A);
 
     /// a <- a * X^k (mod X^{n} + 1)
-    fn vec_znx_rotate_inplace<T: VecZnxApi + Infos>(&self, k: i64, a: &mut T);
+    fn vec_znx_rotate_inplace<A: VecZnxCommon>(&self, k: i64, a: &mut A);
 
     /// b <- phi_k(a) where phi_k: X^i -> X^{i*k} (mod (X^{n} + 1))
-    fn vec_znx_automorphism<T: VecZnxApi + Infos>(&self, k: i64, b: &mut T, a: &T, a_cols: usize);
+    fn vec_znx_automorphism<A: VecZnxCommon, B: VecZnxCommon>(
+        &self,
+        k: i64,
+        b: &mut B,
+        a: &A,
+        a_cols: usize,
+    );
 
     /// a <- phi_k(a) where phi_k: X^i -> X^{i*k} (mod (X^{n} + 1))
-    fn vec_znx_automorphism_inplace<T: VecZnxApi + Infos>(&self, k: i64, a: &mut T, a_cols: usize);
+    fn vec_znx_automorphism_inplace<A: VecZnxCommon>(&self, k: i64, a: &mut A, a_cols: usize);
 
     /// Splits b into subrings and copies them them into a.
     ///
@@ -510,7 +532,12 @@ pub trait VecZnxOps {
     ///
     /// This method requires that all [VecZnx] of b have the same ring degree
     /// and that b.n() * b.len() <= a.n()
-    fn vec_znx_split<T: VecZnxApi + Infos>(&self, b: &mut Vec<T>, a: &T, buf: &mut T);
+    fn vec_znx_split<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        b: &mut Vec<B>,
+        a: &A,
+        buf: &mut C,
+    );
 
     /// Merges the subrings a into b.
     ///
@@ -518,7 +545,7 @@ pub trait VecZnxOps {
     ///
     /// This method requires that all [VecZnx] of a have the same ring degree
     /// and that a.n() * a.len() <= b.n()
-    fn vec_znx_merge<T: VecZnxApi + Infos>(&self, b: &mut T, a: &Vec<T>);
+    fn vec_znx_merge<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &Vec<A>);
 }
 
 impl VecZnxOps for Module {
@@ -531,7 +558,12 @@ impl VecZnxOps for Module {
     }
 
     // c <- a + b
-    fn vec_znx_add<T: VecZnxApi + Infos>(&self, c: &mut T, a: &T, b: &T) {
+    fn vec_znx_add<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        c: &mut C,
+        a: &A,
+        b: &B,
+    ) {
         unsafe {
             vec_znx::vec_znx_add(
                 self.0,
@@ -549,7 +581,7 @@ impl VecZnxOps for Module {
     }
 
     // b <- a + b
-    fn vec_znx_add_inplace<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T) {
+    fn vec_znx_add_inplace<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A) {
         unsafe {
             vec_znx::vec_znx_add(
                 self.0,
@@ -567,7 +599,12 @@ impl VecZnxOps for Module {
     }
 
     // c <- a + b
-    fn vec_znx_sub<T: VecZnxApi + Infos>(&self, c: &mut T, a: &T, b: &T) {
+    fn vec_znx_sub<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        c: &mut C,
+        a: &A,
+        b: &B,
+    ) {
         unsafe {
             vec_znx::vec_znx_sub(
                 self.0,
@@ -585,7 +622,7 @@ impl VecZnxOps for Module {
     }
 
     // b <- a + b
-    fn vec_znx_sub_inplace<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T) {
+    fn vec_znx_sub_inplace<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A) {
         unsafe {
             vec_znx::vec_znx_sub(
                 self.0,
@@ -602,7 +639,7 @@ impl VecZnxOps for Module {
         }
     }
 
-    fn vec_znx_negate<T: VecZnxApi + Infos>(&self, b: &mut T, a: &T) {
+    fn vec_znx_negate<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &A) {
         unsafe {
             vec_znx::vec_znx_negate(
                 self.0,
@@ -616,7 +653,7 @@ impl VecZnxOps for Module {
         }
     }
 
-    fn vec_znx_negate_inplace<T: VecZnxApi + Infos>(&self, a: &mut T) {
+    fn vec_znx_negate_inplace<A: VecZnxCommon>(&self, a: &mut A) {
         unsafe {
             vec_znx::vec_znx_negate(
                 self.0,
@@ -630,22 +667,22 @@ impl VecZnxOps for Module {
         }
     }
 
-    fn vec_znx_rotate<T: VecZnxApi + Infos>(&self, k: i64, a: &mut T, b: &T) {
+    fn vec_znx_rotate<A: VecZnxCommon, B: VecZnxCommon>(&self, k: i64, b: &mut B, a: &A) {
         unsafe {
             vec_znx::vec_znx_rotate(
                 self.0,
                 k,
-                a.as_mut_ptr(),
-                a.cols() as u64,
-                a.n() as u64,
-                b.as_ptr(),
+                b.as_mut_ptr(),
                 b.cols() as u64,
                 b.n() as u64,
+                a.as_ptr(),
+                a.cols() as u64,
+                a.n() as u64,
             )
         }
     }
 
-    fn vec_znx_rotate_inplace<T: VecZnxApi + Infos>(&self, k: i64, a: &mut T) {
+    fn vec_znx_rotate_inplace<A: VecZnxCommon>(&self, k: i64, a: &mut A) {
         unsafe {
             vec_znx::vec_znx_rotate(
                 self.0,
@@ -697,7 +734,13 @@ impl VecZnxOps for Module {
     /// });
     /// izip!(b.data.iter(), c.data.iter()).for_each(|(a, b)| assert_eq!(a, b, "{} != {}", a, b));
     /// ```
-    fn vec_znx_automorphism<T: VecZnxApi + Infos>(&self, k: i64, b: &mut T, a: &T, a_cols: usize) {
+    fn vec_znx_automorphism<A: VecZnxCommon, B: VecZnxCommon>(
+        &self,
+        k: i64,
+        b: &mut B,
+        a: &A,
+        a_cols: usize,
+    ) {
         assert_eq!(a.n(), self.n());
         assert_eq!(b.n(), self.n());
         assert!(a.cols() >= a_cols);
@@ -750,7 +793,7 @@ impl VecZnxOps for Module {
     /// });
     /// izip!(a.data.iter(), b.data.iter()).for_each(|(a, b)| assert_eq!(a, b, "{} != {}", a, b));
     /// ```
-    fn vec_znx_automorphism_inplace<T: VecZnxApi + Infos>(&self, k: i64, a: &mut T, a_cols: usize) {
+    fn vec_znx_automorphism_inplace<A: VecZnxCommon>(&self, k: i64, a: &mut A, a_cols: usize) {
         assert_eq!(a.n(), self.n());
         assert!(a.cols() >= a_cols);
         unsafe {
@@ -767,7 +810,12 @@ impl VecZnxOps for Module {
         }
     }
 
-    fn vec_znx_split<T: VecZnxApi + Infos>(&self, b: &mut Vec<T>, a: &T, buf: &mut T) {
+    fn vec_znx_split<A: VecZnxCommon, B: VecZnxCommon, C: VecZnxCommon>(
+        &self,
+        b: &mut Vec<B>,
+        a: &A,
+        buf: &mut C,
+    ) {
         let (n_in, n_out) = (a.n(), b[0].n());
 
         assert!(
@@ -793,7 +841,7 @@ impl VecZnxOps for Module {
         })
     }
 
-    fn vec_znx_merge<T: VecZnxApi + Infos>(&self, b: &mut T, a: &Vec<T>) {
+    fn vec_znx_merge<A: VecZnxCommon, B: VecZnxCommon>(&self, b: &mut B, a: &Vec<A>) {
         let (n_in, n_out) = (b.n(), a[0].n());
 
         assert!(
diff --git a/rlwe/src/elem.rs b/rlwe/src/elem.rs
index 88c5795..4466c07 100644
--- a/rlwe/src/elem.rs
+++ b/rlwe/src/elem.rs
@@ -1,4 +1,4 @@
-use base2k::{Infos, Module, VecZnx, VecZnxApi, VecZnxBorrow, VecZnxOps, VmpPMat, VmpPMatOps};
+use base2k::{Infos, Module, VecZnx, VecZnxBorrow, VecZnxOps, VmpPMat, VmpPMatOps};
 
 use crate::parameters::Parameters;
 
@@ -19,7 +19,7 @@ pub struct Elem<T> {
     pub log_scale: usize,
 }
 
-pub trait VecZnxCommon: VecZnxApi + Infos {}
+pub trait VecZnxCommon: base2k::VecZnxCommon {}
 impl VecZnxCommon for VecZnx {}
 impl VecZnxCommon for VecZnxBorrow {}
 
diff --git a/rlwe/src/encryptor.rs b/rlwe/src/encryptor.rs
index cb69944..7156d52 100644
--- a/rlwe/src/encryptor.rs
+++ b/rlwe/src/encryptor.rs
@@ -6,7 +6,7 @@ use crate::plaintext::Plaintext;
 use base2k::sampling::Sampling;
 use base2k::{
     Module, Scalar, SvpPPol, SvpPPolOps, VecZnx, VecZnxApi, VecZnxBig, VecZnxBigOps, VecZnxBorrow,
-    VecZnxDft, VecZnxDftOps, VecZnxOps, VmpPMat, VmpPMatOps,
+    VecZnxDft, VecZnxDftOps, VecZnxOps, VmpPMat, VmpPMatOps, cast_mut,
 };
 
 use sampling::source::{Source, new_seed};