diff --git a/backend/src/vec_znx.rs b/backend/src/vec_znx.rs
index b397adb..a4de563 100644
--- a/backend/src/vec_znx.rs
+++ b/backend/src/vec_znx.rs
@@ -71,7 +71,7 @@ impl<D: AsRef<[u8]>> ZnxView for VecZnx<D> {
     type Scalar = i64;
 }
 
-impl<D: AsRef<[u8]>> VecZnx<D> {
+impl VecZnx<Vec<u8>> {
     pub fn rsh_scratch_space(n: usize) -> usize {
         n * std::mem::size_of::<i64>()
     }
diff --git a/core/src/glwe_ciphertext.rs b/core/src/glwe_ciphertext.rs
index 4205637..9c3f32e 100644
--- a/core/src/glwe_ciphertext.rs
+++ b/core/src/glwe_ciphertext.rs
@@ -334,7 +334,7 @@ where
         VecZnx<DataLhs>: VecZnxToRef,
         MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
     {
-        Self::keyswitch_private(self, true, rhs.p(), module, lhs, &rhs.key, scratch);
+        Self::keyswitch_private::<_, _, 1>(self, rhs.p(), module, lhs, &rhs.key, scratch);
     }
 
     pub fn automorphism_add_inplace<DataRhs>(
@@ -347,7 +347,61 @@ where
     {
         unsafe {
             let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
-            Self::keyswitch_private(self, true, rhs.p(), module, &*self_ptr, &rhs.key, scratch);
+            Self::keyswitch_private::<_, _, 1>(self, rhs.p(), module, &*self_ptr, &rhs.key, scratch);
+        }
+    }
+
+    pub fn automorphism_sub_ab<DataLhs, DataRhs>(
+        &mut self,
+        module: &Module<FFT64>,
+        lhs: &GLWECiphertext<DataLhs>,
+        rhs: &AutomorphismKey<DataRhs, FFT64>,
+        scratch: &mut Scratch,
+    ) where
+        VecZnx<DataLhs>: VecZnxToRef,
+        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
+    {
+        Self::keyswitch_private::<_, _, 2>(self, rhs.p(), module, lhs, &rhs.key, scratch);
+    }
+
+    pub fn automorphism_sub_ab_inplace<DataRhs>(
+        &mut self,
+        module: &Module<FFT64>,
+        rhs: &AutomorphismKey<DataRhs, FFT64>,
+        scratch: &mut Scratch,
+    ) where
+        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
+    {
+        unsafe {
+            let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
+            Self::keyswitch_private::<_, _, 2>(self, rhs.p(), module, &*self_ptr, &rhs.key, scratch);
+        }
+    }
+
+    pub fn automorphism_sub_ba<DataLhs, DataRhs>(
+        &mut self,
+        module: &Module<FFT64>,
+        lhs: &GLWECiphertext<DataLhs>,
+        rhs: &AutomorphismKey<DataRhs, FFT64>,
+        scratch: &mut Scratch,
+    ) where
+        VecZnx<DataLhs>: VecZnxToRef,
+        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
+    {
+        Self::keyswitch_private::<_, _, 3>(self, rhs.p(), module, lhs, &rhs.key, scratch);
+    }
+
+    pub fn automorphism_sub_ba_inplace<DataRhs>(
+        &mut self,
+        module: &Module<FFT64>,
+        rhs: &AutomorphismKey<DataRhs, FFT64>,
+        scratch: &mut Scratch,
+    ) where
+        MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
+    {
+        unsafe {
+            let self_ptr: *mut GLWECiphertext<DataSelf> = self as *mut GLWECiphertext<DataSelf>;
+            Self::keyswitch_private::<_, _, 3>(self, rhs.p(), module, &*self_ptr, &rhs.key, scratch);
         }
     }
 
@@ -420,12 +474,11 @@ where
         VecZnx<DataLhs>: VecZnxToRef,
         MatZnxDft<DataRhs, FFT64>: MatZnxDftToRef<FFT64>,
     {
-        Self::keyswitch_private(self, false, 0, module, lhs, rhs, scratch);
+        Self::keyswitch_private::<_, _, 0>(self, 0, module, lhs, rhs, scratch);
     }
 
-    pub(crate) fn keyswitch_private<DataLhs, DataRhs>(
+    pub(crate) fn keyswitch_private<DataLhs, DataRhs, const OP: u8>(
         &mut self,
-        add_self: bool,
         apply_auto: i64,
         module: &Module<FFT64>,
         lhs: &GLWECiphertext<DataLhs>,
@@ -481,8 +534,11 @@ where
                 module.vec_znx_big_automorphism_inplace(apply_auto, &mut res_big, i);
             }
 
-            if add_self {
-                module.vec_znx_big_add_small_inplace(&mut res_big, i, lhs, i);
+            match OP{
+                1=> module.vec_znx_big_add_small_inplace(&mut res_big, i, lhs, i),
+                2=> module.vec_znx_big_sub_small_a_inplace(&mut res_big, i, lhs, i),
+                3=> module.vec_znx_big_sub_small_b_inplace(&mut res_big, i, lhs, i),
+                _=>{},
             }
             module.vec_znx_big_normalize(basek, self, i, &res_big, i, scratch1);
         });
diff --git a/core/src/glwe_ops.rs b/core/src/glwe_ops.rs
index 95357ed..61f9ad2 100644
--- a/core/src/glwe_ops.rs
+++ b/core/src/glwe_ops.rs
@@ -175,10 +175,7 @@ where
         self.set_k(a.k());
     }
 
-    pub fn rotate_inplace<A>(&mut self, module: &Module<FFT64>, k: i64)
-    where
-        A: VecZnxToRef + Infos,
-    {
+    pub fn rotate_inplace(&mut self, module: &Module<FFT64>, k: i64){
         #[cfg(debug_assertions)]
         {
             assert_eq!(self.n(), module.n());
@@ -242,3 +239,9 @@ where
         });
     }
 }
+
+impl GLWECiphertext<Vec<u8>>{
+    pub fn rsh_scratch_space(module: &Module<FFT64>) -> usize{
+        VecZnx::rsh_scratch_space(module.n())
+    }
+}
\ No newline at end of file
diff --git a/core/src/tensor_key.rs b/core/src/tensor_key.rs
index 985f90d..105dace 100644
--- a/core/src/tensor_key.rs
+++ b/core/src/tensor_key.rs
@@ -56,7 +56,7 @@ impl<T, B: Backend> TensorKey<T, B> {
 }
 
 impl TensorKey<Vec<u8>, FFT64> {
-    pub fn encrypt_sk_scratch_space(module: &Module<FFT64>, rank: usize, size: usize) -> usize {
+    pub fn generate_from_sk_scratch_space(module: &Module<FFT64>, rank: usize, size: usize) -> usize {
         module.bytes_of_scalar_znx_dft(1) + GLWESwitchingKey::encrypt_sk_scratch_space(module, rank, size)
     }
 }
@@ -65,7 +65,7 @@ impl<DataSelf> TensorKey<DataSelf, FFT64>
 where
     MatZnxDft<DataSelf, FFT64>: MatZnxDftToMut<FFT64>,
 {
-    pub fn encrypt_sk<DataSk>(
+    pub fn generate_from_sk<DataSk>(
         &mut self,
         module: &Module<FFT64>,
         sk_dft: &SecretKeyFourier<DataSk, FFT64>,
diff --git a/core/src/test_fft64/ggsw.rs b/core/src/test_fft64/ggsw.rs
index 45855a5..5a244ba 100644
--- a/core/src/test_fft64/ggsw.rs
+++ b/core/src/test_fft64/ggsw.rs
@@ -160,7 +160,7 @@ fn test_keyswitch(log_n: usize, basek: usize, k: usize, rank: usize, sigma: f64)
         GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct_in.size())
             | GLWECiphertextFourier::decrypt_scratch_space(&module, ct_out.size())
             | GLWESwitchingKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
-            | TensorKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
+            | TensorKey::generate_from_sk_scratch_space(&module, rank, ksk.size())
             | GGSWCiphertext::keyswitch_scratch_space(
                 &module,
                 ct_out.size(),
@@ -194,7 +194,7 @@ fn test_keyswitch(log_n: usize, basek: usize, k: usize, rank: usize, sigma: f64)
         sigma,
         scratch.borrow(),
     );
-    tsk.encrypt_sk(
+    tsk.generate_from_sk(
         &module,
         &sk_out_dft,
         &mut source_xa,
@@ -286,7 +286,7 @@ fn test_keyswitch_inplace(log_n: usize, basek: usize, k: usize, rank: usize, sig
         GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct.size())
             | GLWECiphertextFourier::decrypt_scratch_space(&module, ct.size())
             | GLWESwitchingKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
-            | TensorKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
+            | TensorKey::generate_from_sk_scratch_space(&module, rank, ksk.size())
             | GGSWCiphertext::keyswitch_inplace_scratch_space(&module, ct.size(), ksk.size(), tsk.size(), rank),
     );
 
@@ -313,7 +313,7 @@ fn test_keyswitch_inplace(log_n: usize, basek: usize, k: usize, rank: usize, sig
         sigma,
         scratch.borrow(),
     );
-    tsk.encrypt_sk(
+    tsk.generate_from_sk(
         &module,
         &sk_out_dft,
         &mut source_xa,
@@ -455,7 +455,7 @@ fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize,
         GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct_in.size())
             | GLWECiphertextFourier::decrypt_scratch_space(&module, ct_out.size())
             | AutomorphismKey::generate_from_sk_scratch_space(&module, rank, auto_key.size())
-            | TensorKey::encrypt_sk_scratch_space(&module, rank, tensor_key.size())
+            | TensorKey::generate_from_sk_scratch_space(&module, rank, tensor_key.size())
             | GGSWCiphertext::automorphism_scratch_space(
                 &module,
                 ct_out.size(),
@@ -483,7 +483,7 @@ fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize,
         sigma,
         scratch.borrow(),
     );
-    tensor_key.encrypt_sk(
+    tensor_key.generate_from_sk(
         &module,
         &sk_dft,
         &mut source_xa,
@@ -575,7 +575,7 @@ fn test_automorphism_inplace(p: i64, log_n: usize, basek: usize, k: usize, rank:
         GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct.size())
             | GLWECiphertextFourier::decrypt_scratch_space(&module, ct.size())
             | AutomorphismKey::generate_from_sk_scratch_space(&module, rank, auto_key.size())
-            | TensorKey::encrypt_sk_scratch_space(&module, rank, tensor_key.size())
+            | TensorKey::generate_from_sk_scratch_space(&module, rank, tensor_key.size())
             | GGSWCiphertext::automorphism_inplace_scratch_space(&module, ct.size(), auto_key.size(), tensor_key.size(), rank),
     );
 
@@ -596,7 +596,7 @@ fn test_automorphism_inplace(p: i64, log_n: usize, basek: usize, k: usize, rank:
         sigma,
         scratch.borrow(),
     );
-    tensor_key.encrypt_sk(
+    tensor_key.generate_from_sk(
         &module,
         &sk_dft,
         &mut source_xa,
diff --git a/core/src/test_fft64/tensor_key.rs b/core/src/test_fft64/tensor_key.rs
index a897253..2a3d40d 100644
--- a/core/src/test_fft64/tensor_key.rs
+++ b/core/src/test_fft64/tensor_key.rs
@@ -30,7 +30,7 @@ fn test_encrypt_sk(log_n: usize, basek: usize, k: usize, sigma: f64, rank: usize
     let mut source_xe: Source = Source::new([0u8; 32]);
     let mut source_xa: Source = Source::new([0u8; 32]);
 
-    let mut scratch: ScratchOwned = ScratchOwned::new(TensorKey::encrypt_sk_scratch_space(
+    let mut scratch: ScratchOwned = ScratchOwned::new(TensorKey::generate_from_sk_scratch_space(
         &module,
         rank,
         tensor_key.size(),
@@ -40,7 +40,7 @@ fn test_encrypt_sk(log_n: usize, basek: usize, k: usize, sigma: f64, rank: usize
     sk.fill_ternary_prob(0.5, &mut source_xs);
 
     let mut sk_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::alloc(&module, rank);
-    sk_dft.dft(&module, &sk);
+    sk_dft.dft(generate_from_sksk);
 
     tensor_key.encrypt_sk(
         &module,