add sext for fheuint

2026-02-10 05:06:44 +01:00 · 2025-11-05 09:23:13 +01:00
parent f84bb02bc9
commit 6cf571c0b0
21 changed files with 243 additions and 192 deletions
--- a/poulpy-core/src/glwe_packing.rs
+++ b/poulpy-core/src/glwe_packing.rs
@@ -83,14 +83,7 @@ where
            }
        }

-        self.glwe_trace(
-            res,
-            log_n - log_gap_out,
-            log_n,
-            *a.get(&0).unwrap(),
-            keys,
-            scratch,
-        );
+        self.glwe_trace(res, log_n - log_gap_out, *a.get(&0).unwrap(), keys, scratch);
    }
 }

--- a/poulpy-core/src/glwe_trace.rs
+++ b/poulpy-core/src/glwe_trace.rs
@@ -31,38 +31,25 @@ impl GLWE<Vec<u8>> {
 }

 impl<D: DataMut> GLWE<D> {
-    pub fn trace<A, H, K, M, BE: Backend>(
-        &mut self,
-        module: &M,
-        start: usize,
-        end: usize,
-        a: &A,
-        keys: &H,
-        scratch: &mut Scratch<BE>,
-    ) where
+    pub fn trace<A, H, K, M, BE: Backend>(&mut self, module: &M, skip: usize, a: &A, keys: &H, scratch: &mut Scratch<BE>)
+    where
        A: GLWEToRef,
        K: GGLWEPreparedToRef<BE> + GetGaloisElement + GGLWEInfos,
        H: GLWEAutomorphismKeyHelper<K, BE>,
        Scratch<BE>: ScratchTakeCore<BE>,
        M: GLWETrace<BE>,
    {
-        module.glwe_trace(self, start, end, a, keys, scratch);
+        module.glwe_trace(self, skip, a, keys, scratch);
    }

-    pub fn trace_inplace<H, K, M, BE: Backend>(
-        &mut self,
-        module: &M,
-        start: usize,
-        end: usize,
-        keys: &H,
-        scratch: &mut Scratch<BE>,
-    ) where
+    pub fn trace_inplace<H, K, M, BE: Backend>(&mut self, module: &M, skip: usize, keys: &H, scratch: &mut Scratch<BE>)
+    where
        K: GGLWEPreparedToRef<BE> + GetGaloisElement + GGLWEInfos,
        H: GLWEAutomorphismKeyHelper<K, BE>,
        Scratch<BE>: ScratchTakeCore<BE>,
        M: GLWETrace<BE>,
    {
-        module.glwe_trace_inplace(self, start, end, keys, scratch);
+        module.glwe_trace_inplace(self, skip, keys, scratch);
    }
 }

@@ -114,7 +101,7 @@ where
        trace
    }

-    fn glwe_trace<R, A, K, H>(&self, res: &mut R, start: usize, end: usize, a: &A, keys: &H, scratch: &mut Scratch<BE>)
+    fn glwe_trace<R, A, K, H>(&self, res: &mut R, skip: usize, a: &A, keys: &H, scratch: &mut Scratch<BE>)
    where
        R: GLWEToMut,
        A: GLWEToRef,
@@ -122,10 +109,10 @@ where
        H: GLWEAutomorphismKeyHelper<K, BE>,
    {
        self.glwe_copy(res, a);
-        self.glwe_trace_inplace(res, start, end, keys, scratch);
+        self.glwe_trace_inplace(res, skip, keys, scratch);
    }

-    fn glwe_trace_inplace<R, K, H>(&self, res: &mut R, start: usize, end: usize, keys: &H, scratch: &mut Scratch<BE>)
+    fn glwe_trace_inplace<R, K, H>(&self, res: &mut R, skip: usize, keys: &H, scratch: &mut Scratch<BE>)
    where
        R: GLWEToMut,
        K: GGLWEPreparedToRef<BE> + GetGaloisElement + GGLWEInfos,
@@ -134,11 +121,11 @@ where
        let res: &mut GLWE<&mut [u8]> = &mut res.to_mut();

        let ksk_infos: &GGLWELayout = &keys.automorphism_key_infos();
+        let log_n: usize = self.log_n();

        assert_eq!(res.n(), self.n() as u32);
        assert_eq!(ksk_infos.n(), self.n() as u32);
-        assert!(start < end);
-        assert!(end <= self.log_n());
+        assert!(skip <= log_n);
        assert_eq!(ksk_infos.rank_in(), res.rank());
        assert_eq!(ksk_infos.rank_out(), res.rank());

@@ -162,7 +149,7 @@ where
                );
            }

-            for i in start..end {
+            for i in skip..log_n {
                self.glwe_rsh(1, &mut self_conv, scratch_1);

                let p: i64 = if i == 0 {
@@ -192,7 +179,7 @@ where
        } else {
            // println!("res: {}", res);

-            for i in start..end {
+            for i in skip..log_n {
                self.glwe_rsh(1, res, scratch);

                let p: i64 = if i == 0 {
@@ -220,14 +207,14 @@ pub trait GLWETrace<BE: Backend> {
        A: GLWEInfos,
        K: GGLWEInfos;

-    fn glwe_trace<R, A, K, H>(&self, res: &mut R, start: usize, end: usize, a: &A, keys: &H, scratch: &mut Scratch<BE>)
+    fn glwe_trace<R, A, K, H>(&self, res: &mut R, skip: usize, a: &A, keys: &H, scratch: &mut Scratch<BE>)
    where
        R: GLWEToMut,
        A: GLWEToRef,
        K: GGLWEPreparedToRef<BE> + GetGaloisElement + GGLWEInfos,
        H: GLWEAutomorphismKeyHelper<K, BE>;

-    fn glwe_trace_inplace<R, K, H>(&self, res: &mut R, start: usize, end: usize, keys: &H, scratch: &mut Scratch<BE>)
+    fn glwe_trace_inplace<R, K, H>(&self, res: &mut R, skip: usize, keys: &H, scratch: &mut Scratch<BE>)
    where
        R: GLWEToMut,
        K: GGLWEPreparedToRef<BE> + GetGaloisElement + GGLWEInfos,
--- a/poulpy-core/src/tests/test_suite/trace.rs
+++ b/poulpy-core/src/tests/test_suite/trace.rs
@@ -114,8 +114,7 @@ where
            auto_keys.insert(*gal_el, atk_prepared);
        });

-        glwe_out.trace_inplace(module, 0, 5, &auto_keys, scratch.borrow());
-        glwe_out.trace_inplace(module, 5, module.log_n(), &auto_keys, scratch.borrow());
+        glwe_out.trace_inplace(module, 0, &auto_keys, scratch.borrow());

        (0..pt_want.size()).for_each(|i| pt_want.data.at_mut(0, i)[0] = pt_have.data.at(0, i)[0]);

--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint.rs
@@ -239,14 +239,7 @@ impl<D: DataMut, T: UnsignedInteger> FheUint<D, T> {

        // Stores this byte (everything else zeroed) into tmp_trace
        let (mut tmp_trace, scratch_1) = scratch.take_glwe(a);
-        module.glwe_trace(
-            &mut tmp_trace,
-            trace_start,
-            module.log_n(),
-            self,
-            keys,
-            scratch_1,
-        );
+        module.glwe_trace(&mut tmp_trace, trace_start, self, keys, scratch_1);

        // Subtracts to self to zero it
        module.glwe_sub_inplace(&mut self.bits, &tmp_trace);
@@ -262,13 +255,7 @@ impl<D: DataMut, T: UnsignedInteger> FheUint<D, T> {
        );

        // Zeroes all other bytes
-        module.glwe_trace_inplace(
-            &mut tmp_fhe_uint_byte,
-            trace_start,
-            module.log_n(),
-            keys,
-            scratch_1,
-        );
+        module.glwe_trace_inplace(&mut tmp_fhe_uint_byte, trace_start, keys, scratch_1);

        // Add self[0] += a[0]
        module.glwe_add_inplace(&mut self.bits, &tmp_fhe_uint_byte);
@@ -324,3 +311,40 @@ impl<D: DataRef, T: UnsignedInteger> GLWEToRef for FheUint<D, T> {
        self.bits.to_ref()
    }
 }
+
+impl<D: DataMut, T: UnsignedInteger> FheUint<D, T> {
+    pub fn sext<M, H, K, BE>(&mut self, module: &M, byte: usize, keys: &H, scratch: &mut Scratch<BE>)
+    where
+        M:,
+        H: GLWEAutomorphismKeyHelper<K, BE>,
+        K: GGLWEPreparedToRef<BE> + GGLWEInfos + GetGaloisElement,
+        BE: Backend,
+        M: ModuleLogN + GLWERotate<BE> + GLWETrace<BE> + GLWEAdd + GLWESub + GLWECopy,
+        Scratch<BE>: ScratchTakeCore<BE>,
+    {
+        assert!(byte < (1 << T::LOG_BYTES));
+
+        let log_gap: usize = module.log_n() - T::LOG_BITS as usize;
+        let rot: i64 = (T::bit_index(byte << 3) << log_gap) as i64;
+
+        let (mut sext, scratch_1) = scratch.take_glwe(self);
+
+        // Extract MSB
+        module.glwe_rotate(-rot, &mut sext, &self.bits);
+        module.glwe_trace_inplace(&mut sext, 0, keys, scratch_1);
+
+        // Replicates MSB in byte
+        for i in 0..3 {
+            let (mut tmp, _) = scratch_1.take_glwe(self);
+            module.glwe_rotate(((1 << T::LOG_BYTES) << log_gap) << i, &mut tmp, &sext);
+            module.glwe_add_inplace(&mut sext, &tmp);
+        }
+
+        // Splice sext
+        let (mut tmp, scratch_2) = scratch_1.take_glwe(self);
+        for i in byte..(1 << T::LOG_BYTES) as usize {
+            FheUint::<&mut [u8], T>::from_glwe_to_mut(&mut tmp).splice_u8(module, i, 0, &self.bits, &sext, keys, scratch_2);
+            module.glwe_copy(&mut self.bits, &tmp);
+        }
+    }
+}
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint_prepared.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint_prepared.rs
@@ -1,9 +1,10 @@
 use std::marker::PhantomData;

+use poulpy_core::LWEFromGLWE;
 use poulpy_core::layouts::{
    Base2K, Dnum, Dsize, GGSWInfos, GGSWPreparedFactory, GLWEInfos, LWEInfos, Rank, TorusPrecision, prepared::GGSWPrepared,
 };
-use poulpy_core::layouts::{GGSWPreparedToMut, GGSWPreparedToRef};
+use poulpy_core::layouts::{GGSWPreparedToMut, GGSWPreparedToRef, LWE};

 use poulpy_core::{GGSWEncryptSk, ScratchTakeCore, layouts::GLWESecretPreparedToRef};
 use poulpy_hal::layouts::{Backend, Data, DataRef, Module};
@@ -14,8 +15,10 @@ use poulpy_hal::{
    source::Source,
 };

-use crate::tfhe::bdd_arithmetic::ToBits;
 use crate::tfhe::bdd_arithmetic::UnsignedInteger;
+use crate::tfhe::bdd_arithmetic::{BDDKey, BDDKeyHelper, BDDKeyInfos, BDDKeyPrepared, BDDKeyPreparedFactory, FheUint, ToBits};
+use crate::tfhe::blind_rotation::BlindRotationAlgo;
+use crate::tfhe::circuit_bootstrapping::CirtuitBootstrappingExecute;

 /// A prepared FHE ciphertext encrypting the bits of an [UnsignedInteger].
 pub struct FheUintPrepared<D: Data, T: UnsignedInteger, B: Backend> {
@@ -23,10 +26,7 @@ pub struct FheUintPrepared<D: Data, T: UnsignedInteger, B: Backend> {
    pub(crate) _phantom: PhantomData<T>,
 }

-impl<T: UnsignedInteger, BE: Backend> FheUintPreparedFactory<T, BE> for Module<BE> where
-    Self: Sized + GGSWPreparedFactory<BE>
-{
-}
+impl<T: UnsignedInteger, BE: Backend> FheUintPreparedFactory<T, BE> for Module<BE> where Self: Sized + GGSWPreparedFactory<BE> {}

 pub trait GetGGSWBit<BE: Backend> {
    fn get_bit(&self, bit: usize) -> GGSWPrepared<&[u8], BE>;
@@ -189,3 +189,88 @@ impl<D: DataRef, T: UnsignedInteger, B: Backend> GGSWInfos for FheUintPrepared<D
        self.bits[0].dnum()
    }
 }
+
+impl<D: DataMut, BRA: BlindRotationAlgo, BE: Backend> BDDKeyPrepared<D, BRA, BE> {
+    pub fn prepare<DR, M>(&mut self, module: &M, other: &BDDKey<DR, BRA>, scratch: &mut Scratch<BE>)
+    where
+        DR: DataRef,
+        M: BDDKeyPreparedFactory<BRA, BE>,
+        Scratch<BE>: ScratchTakeCore<BE>,
+    {
+        module.prepare_bdd_key(self, other, scratch);
+    }
+}
+
+pub trait FheUintPrepare<BRA: BlindRotationAlgo, T: UnsignedInteger, BE: Backend> {
+    fn fhe_uint_prepare_tmp_bytes<R, A>(&self, block_size: usize, extension_factor: usize, res_infos: &R, infos: &A) -> usize
+    where
+        R: GGSWInfos,
+        A: BDDKeyInfos;
+    fn fhe_uint_prepare<DM, DB, DK, K>(
+        &self,
+        res: &mut FheUintPrepared<DM, T, BE>,
+        bits: &FheUint<DB, T>,
+        key: &K,
+        scratch: &mut Scratch<BE>,
+    ) where
+        DM: DataMut,
+        DB: DataRef,
+        DK: DataRef,
+        K: BDDKeyHelper<DK, BRA, BE>;
+}
+
+impl<BRA: BlindRotationAlgo, BE: Backend, T: UnsignedInteger> FheUintPrepare<BRA, T, BE> for Module<BE>
+where
+    Self: LWEFromGLWE<BE> + CirtuitBootstrappingExecute<BRA, BE> + GGSWPreparedFactory<BE>,
+    Scratch<BE>: ScratchTakeCore<BE>,
+{
+    fn fhe_uint_prepare_tmp_bytes<R, A>(&self, block_size: usize, extension_factor: usize, res_infos: &R, bdd_infos: &A) -> usize
+    where
+        R: GGSWInfos,
+        A: BDDKeyInfos,
+    {
+        self.circuit_bootstrapping_execute_tmp_bytes(
+            block_size,
+            extension_factor,
+            res_infos,
+            &bdd_infos.cbt_infos(),
+        )
+    }
+
+    fn fhe_uint_prepare<DM, DB, DK, K>(
+        &self,
+        res: &mut FheUintPrepared<DM, T, BE>,
+        bits: &FheUint<DB, T>,
+        key: &K,
+        scratch: &mut Scratch<BE>,
+    ) where
+        DM: DataMut,
+        DB: DataRef,
+        DK: DataRef,
+        K: BDDKeyHelper<DK, BRA, BE>,
+    {
+        let (cbt, ks) = key.get_cbt_key();
+
+        let mut lwe: LWE<Vec<u8>> = LWE::alloc_from_infos(bits); //TODO: add TakeLWE
+        let (mut tmp_ggsw, scratch_1) = scratch.take_ggsw(res);
+        for (bit, dst) in res.bits.iter_mut().enumerate() {
+            bits.get_bit(self, bit, &mut lwe, ks, scratch_1);
+            cbt.execute_to_constant(self, &mut tmp_ggsw, &lwe, 1, 1, scratch_1);
+            dst.prepare(self, &tmp_ggsw, scratch_1);
+        }
+    }
+}
+
+impl<D: DataMut, T: UnsignedInteger, BE: Backend> FheUintPrepared<D, T, BE> {
+    pub fn prepare<BRA, M, O, K, DK>(&mut self, module: &M, other: &FheUint<O, T>, key: &K, scratch: &mut Scratch<BE>)
+    where
+        BRA: BlindRotationAlgo,
+        O: DataRef,
+        DK: DataRef,
+        K: BDDKeyHelper<DK, BRA, BE>,
+        M: FheUintPrepare<BRA, T, BE>,
+        Scratch<BE>: ScratchTakeCore<BE>,
+    {
+        module.fhe_uint_prepare(self, other, key, scratch);
+    }
+}
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint_prepared_debug.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/ciphertexts/fhe_uint_prepared_debug.rs
@@ -1,6 +1,6 @@
 use std::marker::PhantomData;

-use crate::tfhe::bdd_arithmetic::{BDDKeyPrepared, FheUint, FheUintBlockDebugPrepare, ToBits};
+use crate::tfhe::bdd_arithmetic::{BDDKeyPrepared, FheUint, FheUintPrepareDebug, ToBits};
 use crate::tfhe::{
    bdd_arithmetic::UnsignedInteger, blind_rotation::BlindRotationAlgo, circuit_bootstrapping::CirtuitBootstrappingExecute,
 };
@@ -109,7 +109,7 @@ impl<D: DataRef, T: UnsignedInteger + ToBits> FheUintPreparedDebug<D, T> {
    }
 }

-impl<BRA: BlindRotationAlgo, BE: Backend, T: UnsignedInteger> FheUintBlockDebugPrepare<BRA, T, BE> for Module<BE>
+impl<BRA: BlindRotationAlgo, BE: Backend, T: UnsignedInteger> FheUintPrepareDebug<BRA, T, BE> for Module<BE>
 where
    Self: ModuleN + LWEFromGLWE<BE> + CirtuitBootstrappingExecute<BRA, BE> + GGSWPreparedFactory<BE>,
    Scratch<BE>: ScratchTakeCore<BE>,
@@ -144,7 +144,7 @@ impl<D: DataMut, T: UnsignedInteger> FheUintPreparedDebug<D, T> {
        BRA: BlindRotationAlgo,
        O: DataRef,
        K: DataRef,
-        M: FheUintBlockDebugPrepare<BRA, T, BE>,
+        M: FheUintPrepareDebug<BRA, T, BE>,
        Scratch<BE>: ScratchTakeCore<BE>,
    {
        module.fhe_uint_debug_prepare(self, other, key, scratch);
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/key.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/key.rs
@@ -1,19 +1,19 @@
 use crate::tfhe::bdd_arithmetic::FheUintPreparedDebug;
 use crate::tfhe::{
-    bdd_arithmetic::{FheUint, FheUintPrepared, UnsignedInteger},
+    bdd_arithmetic::{FheUint, UnsignedInteger},
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
    circuit_bootstrapping::{
        CircuitBootstrappingKey, CircuitBootstrappingKeyEncryptSk, CircuitBootstrappingKeyLayout,
-        CircuitBootstrappingKeyPrepared, CircuitBootstrappingKeyPreparedFactory, CirtuitBootstrappingExecute,
+        CircuitBootstrappingKeyPrepared, CircuitBootstrappingKeyPreparedFactory,
    },
 };

 use poulpy_core::layouts::{GLWEAutomorphismKeyHelper, GLWEAutomorphismKeyPrepared};
 use poulpy_core::{
-    GLWEToLWESwitchingKeyEncryptSk, GetDistribution, LWEFromGLWE, ScratchTakeCore,
+    GLWEToLWESwitchingKeyEncryptSk, GetDistribution, ScratchTakeCore,
    layouts::{
-        GGSWInfos, GGSWPreparedFactory, GLWEInfos, GLWESecretToRef, GLWEToLWEKey, GLWEToLWEKeyLayout,
-        GLWEToLWEKeyPreparedFactory, LWE, LWEInfos, LWESecretToRef, prepared::GLWEToLWEKeyPrepared,
+        GLWEInfos, GLWESecretToRef, GLWEToLWEKey, GLWEToLWEKeyLayout, GLWEToLWEKeyPreparedFactory, LWEInfos, LWESecretToRef,
+        prepared::GLWEToLWEKeyPrepared,
    },
 };
 use poulpy_hal::{
@@ -194,77 +194,6 @@ impl<BRA: BlindRotationAlgo, BE: Backend> BDDKeyPrepared<Vec<u8>, BRA, BE> {
    }
 }

-impl<D: DataMut, BRA: BlindRotationAlgo, BE: Backend> BDDKeyPrepared<D, BRA, BE> {
-    pub fn prepare<DR, M>(&mut self, module: &M, other: &BDDKey<DR, BRA>, scratch: &mut Scratch<BE>)
-    where
-        DR: DataRef,
-        M: BDDKeyPreparedFactory<BRA, BE>,
-        Scratch<BE>: ScratchTakeCore<BE>,
-    {
-        module.prepare_bdd_key(self, other, scratch);
-    }
-}
-
-pub trait FheUintPrepare<BRA: BlindRotationAlgo, T: UnsignedInteger, BE: Backend> {
-    fn fhe_uint_prepare_tmp_bytes<R, A>(&self, block_size: usize, extension_factor: usize, res_infos: &R, infos: &A) -> usize
-    where
-        R: GGSWInfos,
-        A: BDDKeyInfos;
-    fn fhe_uint_prepare<DM, DB, DK, K>(
-        &self,
-        res: &mut FheUintPrepared<DM, T, BE>,
-        bits: &FheUint<DB, T>,
-        key: &K,
-        scratch: &mut Scratch<BE>,
-    ) where
-        DM: DataMut,
-        DB: DataRef,
-        DK: DataRef,
-        K: BDDKeyHelper<DK, BRA, BE>;
-}
-
-impl<BRA: BlindRotationAlgo, BE: Backend, T: UnsignedInteger> FheUintPrepare<BRA, T, BE> for Module<BE>
-where
-    Self: LWEFromGLWE<BE> + CirtuitBootstrappingExecute<BRA, BE> + GGSWPreparedFactory<BE>,
-    Scratch<BE>: ScratchTakeCore<BE>,
-{
-    fn fhe_uint_prepare_tmp_bytes<R, A>(&self, block_size: usize, extension_factor: usize, res_infos: &R, bdd_infos: &A) -> usize
-    where
-        R: GGSWInfos,
-        A: BDDKeyInfos,
-    {
-        self.circuit_bootstrapping_execute_tmp_bytes(
-            block_size,
-            extension_factor,
-            res_infos,
-            &bdd_infos.cbt_infos(),
-        )
-    }
-
-    fn fhe_uint_prepare<DM, DB, DK, K>(
-        &self,
-        res: &mut FheUintPrepared<DM, T, BE>,
-        bits: &FheUint<DB, T>,
-        key: &K,
-        scratch: &mut Scratch<BE>,
-    ) where
-        DM: DataMut,
-        DB: DataRef,
-        DK: DataRef,
-        K: BDDKeyHelper<DK, BRA, BE>,
-    {
-        let (cbt, ks) = key.get_cbt_key();
-
-        let mut lwe: LWE<Vec<u8>> = LWE::alloc_from_infos(bits); //TODO: add TakeLWE
-        let (mut tmp_ggsw, scratch_1) = scratch.take_ggsw(res);
-        for (bit, dst) in res.bits.iter_mut().enumerate() {
-            bits.get_bit(self, bit, &mut lwe, ks, scratch_1);
-            cbt.execute_to_constant(self, &mut tmp_ggsw, &lwe, 1, 1, scratch_1);
-            dst.prepare(self, &tmp_ggsw, scratch_1);
-        }
-    }
-}
-
 pub trait BDDKeyHelper<D: DataRef, BRA: BlindRotationAlgo, BE: Backend> {
    fn get_cbt_key(
        &self,
@@ -274,21 +203,7 @@ pub trait BDDKeyHelper<D: DataRef, BRA: BlindRotationAlgo, BE: Backend> {
    );
 }

-impl<D: DataMut, T: UnsignedInteger, BE: Backend> FheUintPrepared<D, T, BE> {
-    pub fn prepare<BRA, M, O, K, DK>(&mut self, module: &M, other: &FheUint<O, T>, key: &K, scratch: &mut Scratch<BE>)
-    where
-        BRA: BlindRotationAlgo,
-        O: DataRef,
-        DK: DataRef,
-        K: BDDKeyHelper<DK, BRA, BE>,
-        M: FheUintPrepare<BRA, T, BE>,
-        Scratch<BE>: ScratchTakeCore<BE>,
-    {
-        module.fhe_uint_prepare(self, other, key, scratch);
-    }
-}
-
-pub trait FheUintBlockDebugPrepare<BRA: BlindRotationAlgo, T: UnsignedInteger, BE: Backend> {
+pub trait FheUintPrepareDebug<BRA: BlindRotationAlgo, T: UnsignedInteger, BE: Backend> {
    fn fhe_uint_debug_prepare<DM, DR0, DR1>(
        &self,
        res: &mut FheUintPreparedDebug<DM, T>,
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/fft64_ref.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/fft64_ref.rs
@@ -5,8 +5,9 @@ use poulpy_backend::FFT64Ref;
 use crate::tfhe::{
    bdd_arithmetic::tests::test_suite::{
        TestContext, test_bdd_add, test_bdd_and, test_bdd_or, test_bdd_prepare, test_bdd_sll, test_bdd_slt, test_bdd_sltu,
-        test_bdd_sra, test_bdd_srl, test_bdd_sub, test_bdd_xor, test_fhe_uint_splice_u8, test_fhe_uint_splice_u16,
-        test_glwe_blind_selection, test_glwe_to_glwe_blind_rotation, test_scalar_to_ggsw_blind_rotation,
+        test_bdd_sra, test_bdd_srl, test_bdd_sub, test_bdd_xor, test_fhe_uint_sext, test_fhe_uint_splice_u8,
+        test_fhe_uint_splice_u16, test_glwe_blind_selection, test_glwe_to_glwe_blind_rotation,
+        test_scalar_to_ggsw_blind_rotation,
    },
    blind_rotation::CGGI,
 };
@@ -14,6 +15,11 @@ use crate::tfhe::{
 static TEST_CONTEXT_CGGI_FFT64_REF: LazyLock<TestContext<CGGI, FFT64Ref>> =
    LazyLock::new(|| TestContext::<CGGI, FFT64Ref>::new());

+#[test]
+fn test_fhe_uint_sext_fft64_ref() {
+    test_fhe_uint_sext(&TEST_CONTEXT_CGGI_FFT64_REF);
+}
+
 #[test]
 fn test_glwe_blind_selection_fft64_ref() {
    test_glwe_blind_selection(&TEST_CONTEXT_CGGI_FFT64_REF)
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/add.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/add.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        Add, BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared,
+        Add, BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/and.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/and.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        And, BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared,
+        And, BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/fheuint.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/fheuint.rs
@@ -16,6 +16,51 @@ use crate::tfhe::{
    blind_rotation::BlindRotationAlgo,
 };

+pub fn test_fhe_uint_sext<BRA: BlindRotationAlgo, BE: Backend>(test_context: &TestContext<BRA, BE>)
+where
+    Module<BE>: GLWEEncryptSk<BE> + GLWERotate<BE> + GLWETrace<BE> + GLWESub + GLWEAdd + GLWEDecrypt<BE>,
+    ScratchOwned<BE>: ScratchOwnedAlloc<BE> + ScratchOwnedBorrow<BE>,
+    Scratch<BE>: ScratchTakeBDD<u32, BE>,
+{
+    let glwe_infos: GLWELayout = TEST_GLWE_INFOS;
+
+    let module: &Module<BE> = &test_context.module;
+    let sk: &GLWESecretPrepared<Vec<u8>, BE> = &test_context.sk_glwe;
+    let keys: &BDDKeyPrepared<Vec<u8>, BRA, BE> = &test_context.bdd_key;
+
+    let mut source_xa: Source = Source::new([2u8; 32]);
+    let mut source_xe: Source = Source::new([3u8; 32]);
+
+    let mut scratch: ScratchOwned<BE> = ScratchOwned::alloc(1 << 22);
+
+    let mut a_enc: FheUint<Vec<u8>, u32> = FheUint::<Vec<u8>, u32>::alloc_from_infos(&glwe_infos);
+
+    for j in 0..3 {
+        for i in 0..32 {
+            let a: u32 = 0xFFFFFFFF >> i;
+
+            a_enc.encrypt_sk(
+                module,
+                a,
+                sk,
+                &mut source_xa,
+                &mut source_xe,
+                scratch.borrow(),
+            );
+
+            a_enc.sext(module, j, keys, scratch.borrow());
+
+            // println!("{:08x} -> {:08x} {:08x}", a, sext(a, j), a_enc.decrypt(module, sk, scratch.borrow()));
+
+            assert_eq!(sext(a, j), a_enc.decrypt(module, sk, scratch.borrow()));
+        }
+    }
+}
+
+pub fn sext(x: u32, byte: usize) -> u32 {
+    x | ((x >> (byte << 3)) & 1) * (0xFFFF_FFFF & (0xFFFF_FFFF << (byte << 3)))
+}
+
 pub fn test_fhe_uint_splice_u8<BRA: BlindRotationAlgo, BE: Backend>(test_context: &TestContext<BRA, BE>)
 where
    Module<BE>: GLWEEncryptSk<BE> + GLWERotate<BE> + GLWETrace<BE> + GLWESub + GLWEAdd + GLWEDecrypt<BE>,
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/or.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/or.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Or,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Or,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/prepare.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/prepare.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPreparedDebug,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPreparedDebug, FheUintPreparedEncryptSk, FheUintPreparedFactory,
        tests::test_suite::{TEST_BASE2K, TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sll.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sll.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Sll,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Sll,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/slt.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/slt.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Slt,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Slt,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sltu.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sltu.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Sltu,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Sltu,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sra.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sra.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Sra,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Sra,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/srl.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/srl.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Srl,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Srl,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sub.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/sub.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Sub,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Sub,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/xor.rs
+++ b/poulpy-schemes/src/tfhe/bdd_arithmetic/tests/test_suite/xor.rs
@@ -11,8 +11,8 @@ use rand::RngCore;

 use crate::tfhe::{
    bdd_arithmetic::{
-        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintBlockDebugPrepare,
-        FheUintPrepare, FheUintPreparedEncryptSk, FheUintPreparedFactory, FheUintPrepared, Xor,
+        BDDKeyEncryptSk, BDDKeyPrepared, BDDKeyPreparedFactory, ExecuteBDDCircuit2WTo1W, FheUint, FheUintPrepare,
+        FheUintPrepareDebug, FheUintPrepared, FheUintPreparedEncryptSk, FheUintPreparedFactory, Xor,
        tests::test_suite::{TEST_GGSW_INFOS, TEST_GLWE_INFOS, TestContext},
    },
    blind_rotation::{BlindRotationAlgo, BlindRotationKey, BlindRotationKeyFactory},
@@ -26,7 +26,7 @@ where
        + GLWENoise<BE>
        + FheUintPreparedFactory<u32, BE>
        + FheUintPreparedEncryptSk<u32, BE>
-        + FheUintBlockDebugPrepare<BRA, u32, BE>
+        + FheUintPrepareDebug<BRA, u32, BE>
        + BDDKeyEncryptSk<BRA, BE>
        + BDDKeyPreparedFactory<BRA, BE>
        + GGSWNoise<BE>
--- a/poulpy-schemes/src/tfhe/circuit_bootstrapping/circuit.rs
+++ b/poulpy-schemes/src/tfhe/circuit_bootstrapping/circuit.rs
@@ -305,7 +305,7 @@ pub fn circuit_bootstrap_core<R, L, D, M, BRA: BlindRotationAlgo, BE: Backend>(
                scratch_2,
            );
        } else {
-            tmp_glwe.trace(module, 0, module.log_n(), &res_glwe, &key.atk, scratch_2);
+            tmp_glwe.trace(module, 0, &res_glwe, &key.atk, scratch_2);
        }

        // let sk_glwe: &poulpy_core::layouts::GLWESecret<&[u8]> = &sk_glwe.to_ref();
@@ -344,8 +344,6 @@ fn post_process<R, A, M, H, K, BE: Backend>(
    let res: &mut GLWE<&mut [u8]> = &mut res.to_mut();
    let a: &GLWE<&[u8]> = &a.to_ref();

-    let log_n: usize = module.log_n();
-
    let mut cts: HashMap<usize, &mut GLWE<Vec<u8>>> = HashMap::new();

    // First partial trace, vanishes all coefficients which are not multiples of gap_in
@@ -353,7 +351,6 @@ fn post_process<R, A, M, H, K, BE: Backend>(
    res.trace(
        module,
        module.log_n() - log_gap_in + 1,
-        log_n,
        a,
        auto_keys,
        scratch,