@@ -1,7 +1,7 @@
 use backend::hal::{
     api::{
-        ScratchAvailable, SvpPPolAlloc, SvpPrepare, TakeVecZnx, TakeVecZnxDft, VecZnxAddScalarInplace, ZnxInfos, ZnxView,
-        ZnxViewMut,
+        FillUniform, Reset, ScratchAvailable, SvpPPolAlloc, SvpPrepare, TakeVecZnx, TakeVecZnxDft, VecZnxAddScalarInplace,
+        ZnxInfos, ZnxView, ZnxViewMut,
     },
     layouts::{Backend, Data, DataMut, DataRef, Module, ReaderFrom, ScalarZnx, ScalarZnxToRef, Scratch, SvpPPol, WriterTo},
 };
@@ -10,12 +10,20 @@
 use crate::{
     Distribution, GGSWCiphertext, GGSWCiphertextExec, GGSWEncryptSkFamily, GGSWLayoutFamily, GLWESecretExec, Infos, LWESecret,
 };
+use std::fmt;
 
+#[derive(Clone)]
 pub struct BlindRotationKeyCGGI<D: Data> {
     pub(crate) keys: Vec<GGSWCiphertext<D>>,
     pub(crate) dist: Distribution,
 }
 
+impl<D: DataRef> fmt::Debug for BlindRotationKeyCGGI<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
 impl<D: Data> PartialEq for BlindRotationKeyCGGI<D> {
     fn eq(&self, other: &Self) -> bool {
         if self.keys.len() != other.keys.len() {
@@ -31,6 +39,30 @@ }
 }
 
 impl<D: Data> Eq for BlindRotationKeyCGGI<D> {}
+
+impl<D: DataRef> fmt::Display for BlindRotationKeyCGGI<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for (i, key) in self.keys.iter().enumerate() {
+            write!(f, "key[{}]: {}", i, key)?;
+        }
+        writeln!(f, "{:?}", self.dist)
+    }
+}
+
+impl<D: DataMut> Reset for BlindRotationKeyCGGI<D> {
+    fn reset(&mut self) {
+        self.keys.iter_mut().for_each(|key| key.reset());
+        self.dist = Distribution::NONE;
+    }
+}
+
+impl<D: DataMut> FillUniform for BlindRotationKeyCGGI<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.keys
+            .iter_mut()
+            .for_each(|key| key.fill_uniform(source));
+    }
+}
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 

@@ -0,0 +1,212 @@
+use backend::hal::{
+    api::{FillUniform, Reset, ScratchAvailable, TakeVecZnx, TakeVecZnxDft, VecZnxAddScalarInplace, ZnxView, ZnxViewMut},
+    layouts::{Backend, Data, DataMut, DataRef, Module, ReaderFrom, ScalarZnx, ScalarZnxToRef, Scratch, WriterTo},
+};
+use sampling::source::Source;
+
+use crate::{Distribution, GGSWCiphertextCompressed, GGSWEncryptSkFamily, GLWESecretExec, Infos, LWESecret};
+use std::fmt;
+
+#[derive(Clone)]
+pub struct BlindRotationKeyCGGICompressed<D: Data> {
+    pub(crate) keys: Vec<GGSWCiphertextCompressed<D>>,
+    pub(crate) dist: Distribution,
+}
+
+impl<D: DataRef> fmt::Debug for BlindRotationKeyCGGICompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: Data> PartialEq for BlindRotationKeyCGGICompressed<D> {
+    fn eq(&self, other: &Self) -> bool {
+        if self.keys.len() != other.keys.len() {
+            return false;
+        }
+        for (a, b) in self.keys.iter().zip(other.keys.iter()) {
+            if a != b {
+                return false;
+            }
+        }
+        self.dist == other.dist
+    }
+}
+
+impl<D: Data> Eq for BlindRotationKeyCGGICompressed<D> {}
+
+impl<D: DataRef> fmt::Display for BlindRotationKeyCGGICompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for (i, key) in self.keys.iter().enumerate() {
+            write!(f, "key[{}]: {}", i, key)?;
+        }
+        writeln!(f, "{:?}", self.dist)
+    }
+}
+
+impl<D: DataMut> Reset for BlindRotationKeyCGGICompressed<D> {
+    fn reset(&mut self) {
+        self.keys.iter_mut().for_each(|key| key.reset());
+        self.dist = Distribution::NONE;
+    }
+}
+
+impl<D: DataMut> FillUniform for BlindRotationKeyCGGICompressed<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.keys
+            .iter_mut()
+            .for_each(|key| key.fill_uniform(source));
+    }
+}
+
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+
+impl<D: DataMut> ReaderFrom for BlindRotationKeyCGGICompressed<D> {
+    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
+        match Distribution::read_from(reader) {
+            Ok(dist) => self.dist = dist,
+            Err(e) => return Err(e),
+        }
+        let len: usize = reader.read_u64::<LittleEndian>()? as usize;
+        if self.keys.len() != len {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidData,
+                format!("self.keys.len()={} != read len={}", self.keys.len(), len),
+            ));
+        }
+        for key in &mut self.keys {
+            key.read_from(reader)?;
+        }
+        Ok(())
+    }
+}
+
+impl<D: DataRef> WriterTo for BlindRotationKeyCGGICompressed<D> {
+    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
+        match self.dist.write_to(writer) {
+            Ok(()) => {}
+            Err(e) => return Err(e),
+        }
+        writer.write_u64::<LittleEndian>(self.keys.len() as u64)?;
+        for key in &self.keys {
+            key.write_to(writer)?;
+        }
+        Ok(())
+    }
+}
+
+impl BlindRotationKeyCGGICompressed<Vec<u8>> {
+    pub fn alloc(n_gglwe: usize, n_lwe: usize, basek: usize, k: usize, rows: usize, rank: usize) -> Self {
+        let mut data: Vec<GGSWCiphertextCompressed<Vec<u8>>> = Vec::with_capacity(n_lwe);
+        (0..n_lwe).for_each(|_| {
+            data.push(GGSWCiphertextCompressed::alloc(
+                n_gglwe, basek, k, rows, 1, rank,
+            ))
+        });
+        Self {
+            keys: data,
+            dist: Distribution::NONE,
+        }
+    }
+
+    pub fn generate_from_sk_scratch_space<B: Backend>(module: &Module<B>, n: usize, basek: usize, k: usize, rank: usize) -> usize
+    where
+        Module<B>: GGSWEncryptSkFamily<B>,
+    {
+        GGSWCiphertextCompressed::encrypt_sk_scratch_space(module, n, basek, k, rank)
+    }
+}
+
+impl<D: DataRef> BlindRotationKeyCGGICompressed<D> {
+    #[allow(dead_code)]
+    pub(crate) fn n(&self) -> usize {
+        self.keys[0].n()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn rows(&self) -> usize {
+        self.keys[0].rows()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn k(&self) -> usize {
+        self.keys[0].k()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn size(&self) -> usize {
+        self.keys[0].size()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn rank(&self) -> usize {
+        self.keys[0].rank()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn basek(&self) -> usize {
+        self.keys[0].basek()
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn block_size(&self) -> usize {
+        match self.dist {
+            Distribution::BinaryBlock(value) => value,
+            _ => 1,
+        }
+    }
+}
+
+impl<D: DataMut> BlindRotationKeyCGGICompressed<D> {
+    pub fn generate_from_sk<DataSkGLWE, DataSkLWE, B: Backend>(
+        &mut self,
+        module: &Module<B>,
+        sk_glwe: &GLWESecretExec<DataSkGLWE, B>,
+        sk_lwe: &LWESecret<DataSkLWE>,
+        seed_xa: [u8; 32],
+        source_xe: &mut Source,
+        sigma: f64,
+        scratch: &mut Scratch<B>,
+    ) where
+        DataSkGLWE: DataRef,
+        DataSkLWE: DataRef,
+        Module<B>: GGSWEncryptSkFamily<B> + VecZnxAddScalarInplace,
+        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(self.keys.len(), sk_lwe.n());
+            assert!(sk_glwe.n() <= module.n());
+            assert_eq!(sk_glwe.rank(), self.keys[0].rank());
+            match sk_lwe.dist {
+                Distribution::BinaryBlock(_)
+                | Distribution::BinaryFixed(_)
+                | Distribution::BinaryProb(_)
+                | Distribution::ZERO => {}
+                _ => panic!(
+                    "invalid GLWESecret distribution: must be BinaryBlock, BinaryFixed or BinaryProb (or ZERO for debugging)"
+                ),
+            }
+        }
+
+        self.dist = sk_lwe.dist;
+
+        let mut pt: ScalarZnx<Vec<u8>> = ScalarZnx::alloc(sk_glwe.n(), 1);
+        let sk_ref: ScalarZnx<&[u8]> = sk_lwe.data.to_ref();
+
+        let mut source_xa: Source = Source::new(seed_xa);
+
+        self.keys.iter_mut().enumerate().for_each(|(i, ggsw)| {
+            pt.at_mut(0, 0)[0] = sk_ref.at(0, 0)[i];
+            ggsw.encrypt_sk(
+                module,
+                &pt,
+                sk_glwe,
+                source_xa.new_seed(),
+                source_xe,
+                sigma,
+                scratch,
+            );
+        });
+    }
+}

@@ -1,9 +1,11 @@
 mod cggi;
 mod key;
+mod key_compressed;
 mod lut;
 
 pub use cggi::*;
 pub use key::*;
+pub use key_compressed::*;
 pub use lut::*;
 
 #[cfg(test)]

@@ -1,130 +0,0 @@
-use backend::{Encoding, FFT64, Module, ScratchOwned, ZnxView};
-use sampling::source::Source;
-
-use crate::{
-    FourierGLWESecret, GLWECiphertext, GLWEPlaintext, GLWESecret, Infos, LWECiphertext, LWESecret,
-    blind_rotation::{
-        cggi::{cggi_blind_rotate, cggi_blind_rotate_scratch_space, mod_switch_2n},
-        key::BlindRotationKeyCGGI,
-        lut::LookUpTable,
-    },
-    lwe::{LWEPlaintext, ciphertext::LWECiphertextToRef},
-};
-
-#[test]
-fn standard() {
-    blind_rotatio_test(224, 1, 1);
-}
-
-#[test]
-fn block_binary() {
-    blind_rotatio_test(224, 7, 1);
-}
-
-#[test]
-fn block_binary_extended() {
-    blind_rotatio_test(224, 7, 2);
-}
-
-fn blind_rotatio_test(n_lwe: usize, block_size: usize, extension_factor: usize) {
-    let module: Module<FFT64> = Module::<FFT64>::new(512);
-    let basek: usize = 19;
-
-    let k_lwe: usize = 24;
-    let k_brk: usize = 3 * basek;
-    let rows_brk: usize = 2; // Ensures first limb is noise-free.
-    let k_lut: usize = 1 * basek;
-    let k_res: usize = 2 * basek;
-    let rank: usize = 1;
-
-    let message_modulus: usize = 1 << 4;
-
-    let mut source_xs: Source = Source::new([2u8; 32]);
-    let mut source_xe: Source = Source::new([2u8; 32]);
-    let mut source_xa: Source = Source::new([1u8; 32]);
-
-    let mut sk_glwe: GLWESecret<Vec<u8>> = GLWESecret::alloc(&module, rank);
-    sk_glwe.fill_ternary_prob(0.5, &mut source_xs);
-    let sk_glwe_dft: FourierGLWESecret<Vec<u8>, FFT64> = FourierGLWESecret::from(&module, &sk_glwe);
-
-    let mut sk_lwe: LWESecret<Vec<u8>> = LWESecret::alloc(n_lwe);
-    sk_lwe.fill_binary_block(block_size, &mut source_xs);
-
-    let mut scratch: ScratchOwned = ScratchOwned::new(BlindRotationKeyCGGI::generate_from_sk_scratch_space(
-        &module, basek, k_brk, rank,
-    ));
-
-    let mut scratch_br: ScratchOwned = ScratchOwned::new(cggi_blind_rotate_scratch_space(
-        &module,
-        block_size,
-        extension_factor,
-        basek,
-        k_res,
-        k_brk,
-        rows_brk,
-        rank,
-    ));
-
-    let mut brk: BlindRotationKeyCGGI<Vec<u8>, FFT64> =
-        BlindRotationKeyCGGI::allocate(&module, n_lwe, basek, k_brk, rows_brk, rank);
-
-    brk.generate_from_sk(
-        &module,
-        &sk_glwe_dft,
-        &sk_lwe,
-        &mut source_xa,
-        &mut source_xe,
-        3.2,
-        scratch.borrow(),
-    );
-
-    let mut lwe: LWECiphertext<Vec<u8>> = LWECiphertext::alloc(n_lwe, basek, k_lwe);
-
-    let mut pt_lwe: LWEPlaintext<Vec<u8>> = LWEPlaintext::alloc(basek, k_lwe);
-
-    let x: i64 = 2;
-    let bits: usize = 8;
-
-    pt_lwe.data.encode_coeff_i64(0, basek, bits, 0, x, bits);
-
-    lwe.encrypt_sk(&pt_lwe, &sk_lwe, &mut source_xa, &mut source_xe, 3.2);
-
-    let mut f: Vec<i64> = vec![0i64; message_modulus];
-    f.iter_mut()
-        .enumerate()
-        .for_each(|(i, x)| *x = 2 * (i as i64) + 1);
-
-    let mut lut: LookUpTable = LookUpTable::alloc(&module, basek, k_lut, extension_factor);
-    lut.set(&module, &f, message_modulus);
-
-    let mut res: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(&module, basek, k_res, rank);
-
-    cggi_blind_rotate(&module, &mut res, &lwe, &lut, &brk, scratch_br.borrow());
-
-    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(&module, basek, k_res);
-
-    res.decrypt(&module, &mut pt_have, &sk_glwe_dft, scratch.borrow());
-
-    let mut lwe_2n: Vec<i64> = vec![0i64; lwe.n() + 1]; // TODO: from scratch space
-
-    mod_switch_2n(
-        2 * lut.domain_size(),
-        &mut lwe_2n,
-        &lwe.to_ref(),
-        lut.rotation_direction(),
-    );
-
-    let pt_want: i64 = (lwe_2n[0]
-        + lwe_2n[1..]
-            .iter()
-            .zip(sk_lwe.data.at(0, 0))
-            .map(|(x, y)| x * y)
-            .sum::<i64>())
-        & (2 * lut.domain_size() - 1) as i64;
-
-    lut.rotate(pt_want);
-
-    // First limb should be exactly equal (test are parameterized such that the noise does not reach
-    // the first limb)
-    assert_eq!(pt_have.data.at(0, 0), lut.data[0].at(0, 0));
-}

@@ -0,0 +1,15 @@
+use backend::hal::tests::serialization::test_reader_writer_interface;
+
+use crate::{BlindRotationKeyCGGI, BlindRotationKeyCGGICompressed};
+
+#[test]
+fn test_cggi_blind_rotation_key_serialization() {
+    let original: BlindRotationKeyCGGI<Vec<u8>> = BlindRotationKeyCGGI::alloc(256, 64, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn test_cggi_blind_rotation_key_compressed_serialization() {
+    let original: BlindRotationKeyCGGICompressed<Vec<u8>> = BlindRotationKeyCGGICompressed::alloc(256, 64, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}

@@ -1,3 +1,4 @@
 mod cpu_spqlios;
 mod generic_cggi;
 mod generic_lut;
+mod generic_serialization;

@@ -29,10 +29,7 @@ self.data.fill_uniform(source);
     }
 }
 
-impl<D: DataMut> Reset for GGLWECiphertext<D>
-where
-    MatZnx<D>: Reset,
-{
+impl<D: DataMut> Reset for GGLWECiphertext<D> {
     fn reset(&mut self) {
         self.data.reset();
         self.basek = 0;

@@ -12,7 +12,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn test_gglwe_serialization_compressed() {
+fn test_gglwe_compressed_serialization() {
     let original: GGLWECiphertextCompressed<Vec<u8>> = GGLWECiphertextCompressed::alloc(1024, 12, 54, 3, 1, 2, 2);
     test_reader_writer_interface(original);
 }
@@ -24,7 +24,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn test_glwe_switching_key_serialization_compressed() {
+fn test_glwe_switching_key_compressed_serialization() {
     let original: GLWESwitchingKeyCompressed<Vec<u8>> = GLWESwitchingKeyCompressed::alloc(1024, 12, 54, 3, 1, 2, 2);
     test_reader_writer_interface(original);
 }
@@ -36,7 +36,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn test_automorphism_key_serialization_compressed() {
+fn test_automorphism_key_compressed_serialization() {
     let original: AutomorphismKeyCompressed<Vec<u8>> = AutomorphismKeyCompressed::alloc(1024, 12, 54, 3, 1, 2);
     test_reader_writer_interface(original);
 }
@@ -48,7 +48,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn test_tensor_key_serialization_compressed() {
+fn test_tensor_key_compressed_serialization() {
     let original: GLWETensorKeyCompressed<Vec<u8>> = GLWETensorKeyCompressed::alloc(1024, 12, 54, 3, 1, 2);
     test_reader_writer_interface(original);
 }

@@ -18,6 +18,12 @@ }
 
 impl<D: DataRef> fmt::Debug for GGSWCiphertext<D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.data)
+    }
+}
+
+impl<D: DataRef> fmt::Display for GGSWCiphertext<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
             f,
             "(GGSWCiphertext: basek={} k={} digits={}) {}",
@@ -26,10 +32,7 @@ )
     }
 }
 
-impl<D: DataMut> Reset for GGSWCiphertext<D>
-where
-    MatZnx<D>: Reset,
-{
+impl<D: DataMut> Reset for GGSWCiphertext<D> {
     fn reset(&mut self) {
         self.data.reset();
         self.basek = 0;
@@ -38,10 +41,7 @@ self.digits = 0;
     }
 }
 
-impl<D: DataMut> FillUniform for GGSWCiphertext<D>
-where
-    MatZnx<D>: FillUniform,
-{
+impl<D: DataMut> FillUniform for GGSWCiphertext<D> {
     fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
         self.data.fill_uniform(source);
     }

@@ -19,6 +19,12 @@ }
 
 impl<D: DataRef> fmt::Debug for GGSWCiphertextCompressed<D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.data)
+    }
+}
+
+impl<D: DataRef> fmt::Display for GGSWCiphertextCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
             f,
             "(GGSWCiphertextCompressed: basek={} k={} digits={}) {}",
@@ -27,10 +33,7 @@ )
     }
 }
 
-impl<D: DataMut> Reset for GGSWCiphertextCompressed<D>
-where
-    MatZnx<D>: Reset,
-{
+impl<D: DataMut> Reset for GGSWCiphertextCompressed<D> {
     fn reset(&mut self) {
         self.data.reset();
         self.basek = 0;
@@ -41,10 +44,7 @@ self.seed = Vec::new();
     }
 }
 
-impl<D: DataMut> FillUniform for GGSWCiphertextCompressed<D>
-where
-    MatZnx<D>: FillUniform,
-{
+impl<D: DataMut> FillUniform for GGSWCiphertextCompressed<D> {
     fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
         self.data.fill_uniform(source);
     }

@@ -9,7 +9,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn ggsw_test_serialization_compressed() {
+fn ggsw_test_compressed_serialization() {
     let original: GGSWCiphertextCompressed<Vec<u8>> = GGSWCiphertextCompressed::alloc(1024, 12, 54, 3, 1, 2);
     test_reader_writer_interface(original);
 }

@@ -45,7 +45,7 @@ rank + 1, // cols in
             rank + 1, // cols out
             ggsw_size,
         );
-        let normalize: usize = module.vec_znx_normalize_tmp_bytes(module.n());
+        let normalize: usize = module.vec_znx_normalize_tmp_bytes(n);
         res_dft + a_dft + (vmp | normalize)
     }
 

@@ -9,7 +9,7 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn test_serialization_compressed() {
+fn test_compressed_serialization() {
     let original: GLWECiphertextCompressed<Vec<u8>> = GLWECiphertextCompressed::alloc(1024, 12, 54, 3);
     test_reader_writer_interface(original);
 }

@@ -8,6 +8,39 @@ GLWECiphertext, GLWEKeyswitchFamily, GLWEToLWESwitchingKeyExec, Infos, LWECiphertext, LWESwitchingKeyExec,
     LWEToGLWESwitchingKeyExec, TakeGLWECt,
 };
 
+impl LWECiphertext<Vec<u8>> {
+    pub fn from_glwe_scratch_space<B: Backend>(
+        module: &Module<B>,
+        n: usize,
+        basek: usize,
+        k_lwe: usize,
+        k_glwe: usize,
+        k_ksk: usize,
+        rank: usize,
+    ) -> usize
+    where
+        Module<B>: GLWEKeyswitchFamily<B>,
+    {
+        GLWECiphertext::bytes_of(n, basek, k_lwe, 1)
+            + GLWECiphertext::keyswitch_scratch_space(module, n, basek, k_lwe, k_glwe, k_ksk, 1, rank, 1)
+    }
+
+    pub fn keyswitch_scratch_space<B: Backend>(
+        module: &Module<B>,
+        n: usize,
+        basek: usize,
+        k_lwe_out: usize,
+        k_lwe_in: usize,
+        k_ksk: usize,
+    ) -> usize
+    where
+        Module<B>: GLWEKeyswitchFamily<B>,
+    {
+        GLWECiphertext::bytes_of(n, basek, k_lwe_out.max(k_lwe_in), 1)
+            + GLWECiphertext::keyswitch_inplace_scratch_space(module, n, basek, k_lwe_out, k_ksk, 1, 1)
+    }
+}
+
 impl<DLwe: DataMut> LWECiphertext<DLwe> {
     pub fn sample_extract<DGlwe: DataRef>(&mut self, a: &GLWECiphertext<DGlwe>) {
         #[cfg(debug_assertions)]

@@ -1,13 +1,18 @@
 use backend::hal::{
     api::{
-        ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxAddNormal, VecZnxFillUniform, VecZnxNormalizeInplace, ZnxView, ZnxViewMut,
+        ScratchAvailable, ScratchOwnedAlloc, ScratchOwnedBorrow, TakeScalarZnx, TakeVecZnx, TakeVecZnxDft, VecZnxAddNormal,
+        VecZnxAddScalarInplace, VecZnxAutomorphismInplace, VecZnxFillUniform, VecZnxNormalizeInplace, VecZnxSwithcDegree,
+        ZnxView, ZnxViewMut, ZnxZero,
     },
-    layouts::{Backend, DataMut, DataRef, Module, ScratchOwned, VecZnx},
+    layouts::{Backend, DataMut, DataRef, Module, Scratch, ScratchOwned, VecZnx},
     oep::{ScratchOwnedAllocImpl, ScratchOwnedBorrowImpl},
 };
 use sampling::source::Source;
 
-use crate::{Infos, LWECiphertext, LWESecret, SIX_SIGMA, lwe::LWEPlaintext};
+use crate::{
+    GGLWEEncryptSkFamily, GLWESecret, GLWEToLWESwitchingKey, Infos, LWECiphertext, LWESecret, LWESwitchingKey,
+    LWEToGLWESwitchingKey, SIX_SIGMA, TakeGLWESecret, TakeGLWESecretExec, lwe::LWEPlaintext,
+};
 
 impl<DataSelf: DataMut> LWECiphertext<DataSelf> {
     pub fn encrypt_sk<DataPt, DataSk, B: Backend>(
@@ -77,3 +82,125 @@ self.data.at_mut(0, i)[0] = tmp_znx.at(0, i)[0];
         });
     }
 }
+
+impl<D: DataMut> GLWEToLWESwitchingKey<D> {
+    pub fn encrypt_sk<DLwe, DGlwe, B: Backend>(
+        &mut self,
+        module: &Module<B>,
+        sk_lwe: &LWESecret<DLwe>,
+        sk_glwe: &GLWESecret<DGlwe>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        sigma: f64,
+        scratch: &mut Scratch<B>,
+    ) where
+        DLwe: DataRef,
+        DGlwe: DataRef,
+        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
+        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert!(sk_lwe.n() <= module.n());
+        }
+
+        let (mut sk_lwe_as_glwe, scratch1) = scratch.take_glwe_secret(sk_glwe.n(), 1);
+        sk_lwe_as_glwe.data.zero();
+        sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n()].copy_from_slice(sk_lwe.data.at(0, 0));
+        module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0);
+
+        self.0.encrypt_sk(
+            module,
+            sk_glwe,
+            &sk_lwe_as_glwe,
+            source_xa,
+            source_xe,
+            sigma,
+            scratch1,
+        );
+    }
+}
+
+impl<D: DataMut> LWEToGLWESwitchingKey<D> {
+    pub fn encrypt_sk<DLwe, DGlwe, B: Backend>(
+        &mut self,
+        module: &Module<B>,
+        sk_lwe: &LWESecret<DLwe>,
+        sk_glwe: &GLWESecret<DGlwe>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        sigma: f64,
+        scratch: &mut Scratch<B>,
+    ) where
+        DLwe: DataRef,
+        DGlwe: DataRef,
+        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
+        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert!(sk_lwe.n() <= module.n());
+        }
+
+        let (mut sk_lwe_as_glwe, scratch1) = scratch.take_glwe_secret(sk_glwe.n(), 1);
+        sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n()].copy_from_slice(sk_lwe.data.at(0, 0));
+        sk_lwe_as_glwe.data.at_mut(0, 0)[sk_lwe.n()..].fill(0);
+        module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0);
+
+        self.0.encrypt_sk(
+            module,
+            &sk_lwe_as_glwe,
+            &sk_glwe,
+            source_xa,
+            source_xe,
+            sigma,
+            scratch1,
+        );
+    }
+}
+
+impl<D: DataMut> LWESwitchingKey<D> {
+    pub fn encrypt_sk<DIn, DOut, B: Backend>(
+        &mut self,
+        module: &Module<B>,
+        sk_lwe_in: &LWESecret<DIn>,
+        sk_lwe_out: &LWESecret<DOut>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        sigma: f64,
+        scratch: &mut Scratch<B>,
+    ) where
+        DIn: DataRef,
+        DOut: DataRef,
+        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
+        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert!(sk_lwe_in.n() <= self.n());
+            assert!(sk_lwe_out.n() <= self.n());
+            assert!(self.n() <= module.n());
+        }
+
+        let (mut sk_in_glwe, scratch1) = scratch.take_glwe_secret(self.n(), 1);
+        let (mut sk_out_glwe, scratch2) = scratch1.take_glwe_secret(self.n(), 1);
+
+        sk_out_glwe.data.at_mut(0, 0)[..sk_lwe_out.n()].copy_from_slice(sk_lwe_out.data.at(0, 0));
+        sk_out_glwe.data.at_mut(0, 0)[sk_lwe_out.n()..].fill(0);
+        module.vec_znx_automorphism_inplace(-1, &mut sk_out_glwe.data.as_vec_znx_mut(), 0);
+
+        sk_in_glwe.data.at_mut(0, 0)[..sk_lwe_in.n()].copy_from_slice(sk_lwe_in.data.at(0, 0));
+        sk_in_glwe.data.at_mut(0, 0)[sk_lwe_in.n()..].fill(0);
+        module.vec_znx_automorphism_inplace(-1, &mut sk_in_glwe.data.as_vec_znx_mut(), 0);
+
+        self.0.encrypt_sk(
+            module,
+            &sk_in_glwe,
+            &sk_out_glwe,
+            source_xa,
+            source_xe,
+            sigma,
+            scratch2,
+        );
+    }
+}

@@ -1,20 +1,39 @@
 use backend::hal::{
-    api::{
-        ScratchAvailable, TakeScalarZnx, TakeVecZnx, TakeVecZnxDft, VecZnxAddScalarInplace, VecZnxAutomorphismInplace,
-        VecZnxSwithcDegree, ZnxView, ZnxViewMut, ZnxZero,
-    },
-    layouts::{Backend, Data, DataMut, DataRef, MatZnx, Module, ReaderFrom, Scratch, WriterTo},
+    api::{FillUniform, Reset},
+    layouts::{Backend, Data, DataMut, DataRef, MatZnx, Module, ReaderFrom, WriterTo},
 };
-use sampling::source::Source;
+
+use crate::{GGLWEEncryptSkFamily, GLWESecret, GLWESecretExec, GLWESwitchingKey, Infos};
 
-use crate::{
-    GGLWEEncryptSkFamily, GLWECiphertext, GLWEKeyswitchFamily, GLWESecret, GLWESecretExec, GLWESwitchingKey, Infos,
-    LWECiphertext, LWESecret, TakeGLWESecret, TakeGLWESecretExec,
-};
+use std::fmt;
 
 /// A special [GLWESwitchingKey] required to for the conversion from [GLWECiphertext] to [LWECiphertext].
-#[derive(PartialEq, Eq)]
+#[derive(PartialEq, Eq, Clone)]
 pub struct GLWEToLWESwitchingKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
+
+impl<D: DataRef> fmt::Debug for GLWEToLWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for GLWEToLWESwitchingKey<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
+
+impl<D: DataMut> Reset for GLWEToLWESwitchingKey<D> {
+    fn reset(&mut self) {
+        self.0.reset();
+    }
+}
+
+impl<D: DataRef> fmt::Display for GLWEToLWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(GLWEToLWESwitchingKey) {}", self.0)
+    }
+}
 
 impl<D: Data> Infos for GLWEToLWESwitchingKey<D> {
     type Inner = MatZnx<D>;
@@ -76,46 +95,32 @@ + (GLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, rank_in, 1) | GLWESecret::bytes_of(n, rank_in))
     }
 }
 
-impl<D: DataMut> GLWEToLWESwitchingKey<D> {
-    pub fn encrypt_sk<DLwe, DGlwe, B: Backend>(
-        &mut self,
-        module: &Module<B>,
-        sk_lwe: &LWESecret<DLwe>,
-        sk_glwe: &GLWESecret<DGlwe>,
-        source_xa: &mut Source,
-        source_xe: &mut Source,
-        sigma: f64,
-        scratch: &mut Scratch<B>,
-    ) where
-        DLwe: DataRef,
-        DGlwe: DataRef,
-        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
-        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
-    {
-        #[cfg(debug_assertions)]
-        {
-            assert!(sk_lwe.n() <= module.n());
-        }
+#[derive(PartialEq, Eq, Clone)]
+pub struct LWEToGLWESwitchingKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
 
-        let (mut sk_lwe_as_glwe, scratch1) = scratch.take_glwe_secret(sk_glwe.n(), 1);
-        sk_lwe_as_glwe.data.zero();
-        sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n()].copy_from_slice(sk_lwe.data.at(0, 0));
-        module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0);
+impl<D: DataRef> fmt::Debug for LWEToGLWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for LWEToGLWESwitchingKey<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
 
-        self.0.encrypt_sk(
-            module,
-            sk_glwe,
-            &sk_lwe_as_glwe,
-            source_xa,
-            source_xe,
-            sigma,
-            scratch1,
-        );
+impl<D: DataMut> Reset for LWEToGLWESwitchingKey<D> {
+    fn reset(&mut self) {
+        self.0.reset();
     }
 }
 
-#[derive(PartialEq, Eq)]
-pub struct LWEToGLWESwitchingKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
+impl<D: DataRef> fmt::Display for LWEToGLWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(LWEToGLWESwitchingKey) {}", self.0)
+    }
+}
 
 impl<D: Data> Infos for LWEToGLWESwitchingKey<D> {
     type Inner = MatZnx<D>;
@@ -176,46 +181,32 @@ GLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, 1, rank_out) + GLWESecret::bytes_of(n, 1)
     }
 }
 
-impl<D: DataMut> LWEToGLWESwitchingKey<D> {
-    pub fn encrypt_sk<DLwe, DGlwe, B: Backend>(
-        &mut self,
-        module: &Module<B>,
-        sk_lwe: &LWESecret<DLwe>,
-        sk_glwe: &GLWESecret<DGlwe>,
-        source_xa: &mut Source,
-        source_xe: &mut Source,
-        sigma: f64,
-        scratch: &mut Scratch<B>,
-    ) where
-        DLwe: DataRef,
-        DGlwe: DataRef,
-        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
-        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
-    {
-        #[cfg(debug_assertions)]
-        {
-            assert!(sk_lwe.n() <= module.n());
-        }
+#[derive(PartialEq, Eq, Clone)]
+pub struct LWESwitchingKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
 
-        let (mut sk_lwe_as_glwe, scratch1) = scratch.take_glwe_secret(sk_glwe.n(), 1);
-        sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n()].copy_from_slice(sk_lwe.data.at(0, 0));
-        sk_lwe_as_glwe.data.at_mut(0, 0)[sk_lwe.n()..].fill(0);
-        module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0);
+impl<D: DataRef> fmt::Debug for LWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for LWESwitchingKey<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
 
-        self.0.encrypt_sk(
-            module,
-            &sk_lwe_as_glwe,
-            &sk_glwe,
-            source_xa,
-            source_xe,
-            sigma,
-            scratch1,
-        );
+impl<D: DataMut> Reset for LWESwitchingKey<D> {
+    fn reset(&mut self) {
+        self.0.reset();
     }
 }
 
-#[derive(PartialEq, Eq)]
-pub struct LWESwitchingKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
+impl<D: DataRef> fmt::Display for LWESwitchingKey<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(LWESwitchingKey) {}", self.0)
+    }
+}
 
 impl<D: Data> Infos for LWESwitchingKey<D> {
     type Inner = MatZnx<D>;
@@ -277,82 +268,3 @@ + GLWESecretExec::bytes_of(module, n, 1)
             + GLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, 1, 1)
     }
 }
-
-impl<D: DataMut> LWESwitchingKey<D> {
-    pub fn encrypt_sk<DIn, DOut, B: Backend>(
-        &mut self,
-        module: &Module<B>,
-        sk_lwe_in: &LWESecret<DIn>,
-        sk_lwe_out: &LWESecret<DOut>,
-        source_xa: &mut Source,
-        source_xe: &mut Source,
-        sigma: f64,
-        scratch: &mut Scratch<B>,
-    ) where
-        DIn: DataRef,
-        DOut: DataRef,
-        Module<B>: GGLWEEncryptSkFamily<B> + VecZnxAutomorphismInplace + VecZnxSwithcDegree + VecZnxAddScalarInplace,
-        Scratch<B>: ScratchAvailable + TakeScalarZnx + TakeVecZnxDft<B> + TakeGLWESecretExec<B> + TakeVecZnx,
-    {
-        #[cfg(debug_assertions)]
-        {
-            assert!(sk_lwe_in.n() <= self.n());
-            assert!(sk_lwe_out.n() <= self.n());
-            assert!(self.n() <= module.n());
-        }
-
-        let (mut sk_in_glwe, scratch1) = scratch.take_glwe_secret(self.n(), 1);
-        let (mut sk_out_glwe, scratch2) = scratch1.take_glwe_secret(self.n(), 1);
-
-        sk_out_glwe.data.at_mut(0, 0)[..sk_lwe_out.n()].copy_from_slice(sk_lwe_out.data.at(0, 0));
-        sk_out_glwe.data.at_mut(0, 0)[sk_lwe_out.n()..].fill(0);
-        module.vec_znx_automorphism_inplace(-1, &mut sk_out_glwe.data.as_vec_znx_mut(), 0);
-
-        sk_in_glwe.data.at_mut(0, 0)[..sk_lwe_in.n()].copy_from_slice(sk_lwe_in.data.at(0, 0));
-        sk_in_glwe.data.at_mut(0, 0)[sk_lwe_in.n()..].fill(0);
-        module.vec_znx_automorphism_inplace(-1, &mut sk_in_glwe.data.as_vec_znx_mut(), 0);
-
-        self.0.encrypt_sk(
-            module,
-            &sk_in_glwe,
-            &sk_out_glwe,
-            source_xa,
-            source_xe,
-            sigma,
-            scratch2,
-        );
-    }
-}
-
-impl LWECiphertext<Vec<u8>> {
-    pub fn from_glwe_scratch_space<B: Backend>(
-        module: &Module<B>,
-        n: usize,
-        basek: usize,
-        k_lwe: usize,
-        k_glwe: usize,
-        k_ksk: usize,
-        rank: usize,
-    ) -> usize
-    where
-        Module<B>: GLWEKeyswitchFamily<B>,
-    {
-        GLWECiphertext::bytes_of(n, basek, k_lwe, 1)
-            + GLWECiphertext::keyswitch_scratch_space(module, n, basek, k_lwe, k_glwe, k_ksk, 1, rank, 1)
-    }
-
-    pub fn keyswitch_scratch_space<B: Backend>(
-        module: &Module<B>,
-        n: usize,
-        basek: usize,
-        k_lwe_out: usize,
-        k_lwe_in: usize,
-        k_ksk: usize,
-    ) -> usize
-    where
-        Module<B>: GLWEKeyswitchFamily<B>,
-    {
-        GLWECiphertext::bytes_of(n, basek, k_lwe_out.max(k_lwe_in), 1)
-            + GLWECiphertext::keyswitch_inplace_scratch_space(module, n, basek, k_lwe_out, k_ksk, 1, 1)
-    }
-}

@@ -2,11 +2,14 @@ use std::fmt;
 
 use backend::hal::{
     api::{FillUniform, Reset, VecZnxFillUniform, ZnxInfos, ZnxView, ZnxViewMut},
-    layouts::{Backend, Data, DataMut, DataRef, Module, ReaderFrom, VecZnx, WriterTo},
+    layouts::{Backend, Data, DataMut, DataRef, MatZnx, Module, ReaderFrom, VecZnx, WriterTo},
 };
 use sampling::source::Source;
 
-use crate::{Decompress, Infos, LWECiphertext, SetMetaData};
+use crate::{
+    Decompress, GGLWEEncryptSkFamily, GLWESwitchingKeyCompressed, GLWEToLWESwitchingKey, Infos, LWECiphertext, LWESwitchingKey,
+    LWEToGLWESwitchingKey, SetMetaData,
+};
 
 #[derive(PartialEq, Eq, Clone)]
 pub struct LWECiphertextCompressed<D: Data> {
@@ -47,10 +50,7 @@ self.seed = [0u8; 32];
     }
 }
 
-impl<D: DataMut> FillUniform for LWECiphertextCompressed<D>
-where
-    VecZnx<D>: FillUniform,
-{
+impl<D: DataMut> FillUniform for LWECiphertextCompressed<D> {
     fn fill_uniform(&mut self, source: &mut Source) {
         self.data.fill_uniform(source);
     }
@@ -132,3 +132,267 @@ self.data.at_mut(0, i)[0] = other.data.at(0, i)[0];
         });
     }
 }
+
+#[derive(PartialEq, Eq, Clone)]
+pub struct GLWEToLWESwitchingKeyCompressed<D: Data>(pub(crate) GLWESwitchingKeyCompressed<D>);
+
+impl<D: DataRef> fmt::Debug for GLWEToLWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for GLWEToLWESwitchingKeyCompressed<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
+
+impl<D: DataMut> Reset for GLWEToLWESwitchingKeyCompressed<D> {
+    fn reset(&mut self) {
+        self.0.reset();
+    }
+}
+
+impl<D: DataRef> fmt::Display for GLWEToLWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(GLWEToLWESwitchingKeyCompressed) {}", self.0)
+    }
+}
+
+impl<D: Data> Infos for GLWEToLWESwitchingKeyCompressed<D> {
+    type Inner = MatZnx<D>;
+
+    fn inner(&self) -> &Self::Inner {
+        &self.0.inner()
+    }
+
+    fn basek(&self) -> usize {
+        self.0.basek()
+    }
+
+    fn k(&self) -> usize {
+        self.0.k()
+    }
+}
+
+impl<D: Data> GLWEToLWESwitchingKeyCompressed<D> {
+    pub fn digits(&self) -> usize {
+        self.0.digits()
+    }
+
+    pub fn rank(&self) -> usize {
+        self.0.rank()
+    }
+
+    pub fn rank_in(&self) -> usize {
+        self.0.rank_in()
+    }
+
+    pub fn rank_out(&self) -> usize {
+        self.0.rank_out()
+    }
+}
+
+impl<D: DataMut> ReaderFrom for GLWEToLWESwitchingKeyCompressed<D> {
+    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
+        self.0.read_from(reader)
+    }
+}
+
+impl<D: DataRef> WriterTo for GLWEToLWESwitchingKeyCompressed<D> {
+    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
+        self.0.write_to(writer)
+    }
+}
+
+impl GLWEToLWESwitchingKeyCompressed<Vec<u8>> {
+    pub fn alloc(n: usize, basek: usize, k: usize, rows: usize, rank_in: usize) -> Self {
+        Self(GLWESwitchingKeyCompressed::alloc(
+            n, basek, k, rows, 1, rank_in, 1,
+        ))
+    }
+
+    pub fn encrypt_sk_scratch_space<B: Backend>(module: &Module<B>, n: usize, basek: usize, k: usize, rank_in: usize) -> usize
+    where
+        Module<B>: GGLWEEncryptSkFamily<B>,
+    {
+        GLWEToLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, rank_in)
+    }
+}
+
+#[derive(PartialEq, Eq, Clone)]
+pub struct LWEToGLWESwitchingKeyCompressed<D: Data>(pub(crate) GLWESwitchingKeyCompressed<D>);
+
+impl<D: DataRef> fmt::Debug for LWEToGLWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for LWEToGLWESwitchingKeyCompressed<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
+
+impl<D: DataMut> Reset for LWEToGLWESwitchingKeyCompressed<D> {
+    fn reset(&mut self) {
+        self.0.reset();
+    }
+}
+
+impl<D: DataRef> fmt::Display for LWEToGLWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(LWEToGLWESwitchingKeyCompressed) {}", self.0)
+    }
+}
+
+impl<D: Data> Infos for LWEToGLWESwitchingKeyCompressed<D> {
+    type Inner = MatZnx<D>;
+
+    fn inner(&self) -> &Self::Inner {
+        &self.0.inner()
+    }
+
+    fn basek(&self) -> usize {
+        self.0.basek()
+    }
+
+    fn k(&self) -> usize {
+        self.0.k()
+    }
+}
+
+impl<D: Data> LWEToGLWESwitchingKeyCompressed<D> {
+    pub fn digits(&self) -> usize {
+        self.0.digits()
+    }
+
+    pub fn rank(&self) -> usize {
+        self.0.rank()
+    }
+
+    pub fn rank_in(&self) -> usize {
+        self.0.rank_in()
+    }
+
+    pub fn rank_out(&self) -> usize {
+        self.0.rank_out()
+    }
+}
+
+impl<D: DataMut> ReaderFrom for LWEToGLWESwitchingKeyCompressed<D> {
+    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
+        self.0.read_from(reader)
+    }
+}
+
+impl<D: DataRef> WriterTo for LWEToGLWESwitchingKeyCompressed<D> {
+    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
+        self.0.write_to(writer)
+    }
+}
+
+impl LWEToGLWESwitchingKeyCompressed<Vec<u8>> {
+    pub fn alloc(n: usize, basek: usize, k: usize, rows: usize, rank_out: usize) -> Self {
+        Self(GLWESwitchingKeyCompressed::alloc(
+            n, basek, k, rows, 1, 1, rank_out,
+        ))
+    }
+
+    pub fn encrypt_sk_scratch_space<B: Backend>(module: &Module<B>, n: usize, basek: usize, k: usize, rank_out: usize) -> usize
+    where
+        Module<B>: GGLWEEncryptSkFamily<B>,
+    {
+        LWEToGLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, rank_out)
+    }
+}
+
+#[derive(PartialEq, Eq, Clone)]
+pub struct LWESwitchingKeyCompressed<D: Data>(pub(crate) GLWESwitchingKeyCompressed<D>);
+
+impl<D: DataRef> fmt::Debug for LWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+impl<D: DataMut> FillUniform for LWESwitchingKeyCompressed<D> {
+    fn fill_uniform(&mut self, source: &mut sampling::source::Source) {
+        self.0.fill_uniform(source);
+    }
+}
+
+impl<D: DataMut> Reset for LWESwitchingKeyCompressed<D> {
+    fn reset(&mut self) {
+        self.0.reset();
+    }
+}
+
+impl<D: DataRef> fmt::Display for LWESwitchingKeyCompressed<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "(LWESwitchingKeyCompressed) {}", self.0)
+    }
+}
+
+impl<D: Data> Infos for LWESwitchingKeyCompressed<D> {
+    type Inner = MatZnx<D>;
+
+    fn inner(&self) -> &Self::Inner {
+        &self.0.inner()
+    }
+
+    fn basek(&self) -> usize {
+        self.0.basek()
+    }
+
+    fn k(&self) -> usize {
+        self.0.k()
+    }
+}
+
+impl<D: Data> LWESwitchingKeyCompressed<D> {
+    pub fn digits(&self) -> usize {
+        self.0.digits()
+    }
+
+    pub fn rank(&self) -> usize {
+        self.0.rank()
+    }
+
+    pub fn rank_in(&self) -> usize {
+        self.0.rank_in()
+    }
+
+    pub fn rank_out(&self) -> usize {
+        self.0.rank_out()
+    }
+}
+
+impl<D: DataMut> ReaderFrom for LWESwitchingKeyCompressed<D> {
+    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
+        self.0.read_from(reader)
+    }
+}
+
+impl<D: DataRef> WriterTo for LWESwitchingKeyCompressed<D> {
+    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
+        self.0.write_to(writer)
+    }
+}
+
+impl LWESwitchingKeyCompressed<Vec<u8>> {
+    pub fn alloc(n: usize, basek: usize, k: usize, rows: usize) -> Self {
+        Self(GLWESwitchingKeyCompressed::alloc(
+            n, basek, k, rows, 1, 1, 1,
+        ))
+    }
+
+    pub fn encrypt_sk_scratch_space<B: Backend>(module: &Module<B>, n: usize, basek: usize, k: usize) -> usize
+    where
+        Module<B>: GGLWEEncryptSkFamily<B>,
+    {
+        LWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k)
+    }
+}

@@ -1,6 +1,9 @@
 use backend::hal::tests::serialization::test_reader_writer_interface;
 
-use crate::{LWECiphertext, LWECiphertextCompressed};
+use crate::{
+    GLWEToLWESwitchingKey, GLWEToLWESwitchingKeyCompressed, LWECiphertext, LWECiphertextCompressed, LWESwitchingKey,
+    LWESwitchingKeyCompressed, LWEToGLWESwitchingKey, LWEToGLWESwitchingKeyCompressed,
+};
 
 #[test]
 fn lwe_serialization() {
@@ -9,7 +12,43 @@ test_reader_writer_interface(original);
 }
 
 #[test]
-fn lwe_serialization_compressed() {
+fn lwe_compressed_serialization() {
     let original: LWECiphertextCompressed<Vec<u8>> = LWECiphertextCompressed::alloc(12, 54);
     test_reader_writer_interface(original);
 }
+
+#[test]
+fn glwe_to_lwe_switching_key_serialization() {
+    let original: GLWEToLWESwitchingKey<Vec<u8>> = GLWEToLWESwitchingKey::alloc(1024, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn glwe_to_lwe_switching_key_compressed_serialization() {
+    let original: GLWEToLWESwitchingKeyCompressed<Vec<u8>> = GLWEToLWESwitchingKeyCompressed::alloc(1024, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn lwe_to_glwe_switching_key_serialization() {
+    let original: LWEToGLWESwitchingKey<Vec<u8>> = LWEToGLWESwitchingKey::alloc(1024, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn lwe_to_glwe_switching_key_compressed_serialization() {
+    let original: LWEToGLWESwitchingKeyCompressed<Vec<u8>> = LWEToGLWESwitchingKeyCompressed::alloc(1024, 12, 54, 2, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn lwe_switching_key_serialization() {
+    let original: LWESwitchingKey<Vec<u8>> = LWESwitchingKey::alloc(1024, 12, 54, 2);
+    test_reader_writer_interface(original);
+}
+
+#[test]
+fn lwe_switching_key_compressed_serialization() {
+    let original: LWESwitchingKeyCompressed<Vec<u8>> = LWESwitchingKeyCompressed::alloc(1024, 12, 54, 2);
+    test_reader_writer_interface(original);
+}

@@ -15,9 +15,14 @@ }
     }
 
     pub fn branch(&mut self) -> ([u8; 32], Self) {
-        let mut seed = [0; 32];
-        self.source.fill_bytes(&mut seed);
+        let seed: [u8; 32] = self.new_seed();
         (seed, Source::new(seed))
+    }
+
+    pub fn new_seed(&mut self) -> [u8; 32] {
+        let mut seed: [u8; 32] = [0u8; 32];
+        self.fill_bytes(&mut seed);
+        seed
     }
 
     #[inline(always)]