poulpy_core/encryption/
glwe_to_lwe_key.rs

1use poulpy_hal::{
2    api::{ModuleN, VecZnxAutomorphismInplace, VecZnxAutomorphismInplaceTmpBytes},
3    layouts::{Backend, DataMut, Module, Scratch, ZnxView, ZnxViewMut, ZnxZero},
4    source::Source,
5};
6
7use crate::{
8    GGLWEEncryptSk, ScratchTakeCore,
9    layouts::{
10        GGLWE, GGLWEInfos, GGLWEToMut, GLWESecret, GLWESecretToRef, GLWEToLWEKey, LWEInfos, LWESecret, LWESecretToRef, Rank,
11        prepared::{GLWESecretPrepared, GLWESecretPreparedFactory},
12    },
13};
14
15impl GLWEToLWEKey<Vec<u8>> {
16    pub fn encrypt_sk_tmp_bytes<M, A, BE: Backend>(module: &M, infos: &A) -> usize
17    where
18        A: GGLWEInfos,
19        M: GLWEToLWESwitchingKeyEncryptSk<BE>,
20    {
21        module.glwe_to_lwe_key_encrypt_sk_tmp_bytes(infos)
22    }
23}
24
25impl<D: DataMut> GLWEToLWEKey<D> {
26    pub fn encrypt_sk<M, S1, S2, BE: Backend>(
27        &mut self,
28        module: &M,
29        sk_lwe: &S1,
30        sk_glwe: &S2,
31        source_xa: &mut Source,
32        source_xe: &mut Source,
33        scratch: &mut Scratch<BE>,
34    ) where
35        M: GLWEToLWESwitchingKeyEncryptSk<BE>,
36        S1: LWESecretToRef,
37        S2: GLWESecretToRef,
38        Scratch<BE>: ScratchTakeCore<BE>,
39    {
40        module.glwe_to_lwe_key_encrypt_sk(self, sk_lwe, sk_glwe, source_xa, source_xe, scratch);
41    }
42}
43
44pub trait GLWEToLWESwitchingKeyEncryptSk<BE: Backend> {
45    fn glwe_to_lwe_key_encrypt_sk_tmp_bytes<A>(&self, infos: &A) -> usize
46    where
47        A: GGLWEInfos;
48
49    fn glwe_to_lwe_key_encrypt_sk<R, S1, S2>(
50        &self,
51        res: &mut R,
52        sk_lwe: &S1,
53        sk_glwe: &S2,
54        source_xa: &mut Source,
55        source_xe: &mut Source,
56        scratch: &mut Scratch<BE>,
57    ) where
58        S1: LWESecretToRef,
59        S2: GLWESecretToRef,
60        R: GGLWEToMut;
61}
62
63impl<BE: Backend> GLWEToLWESwitchingKeyEncryptSk<BE> for Module<BE>
64where
65    Self: ModuleN
66        + GGLWEEncryptSk<BE>
67        + GLWESecretPreparedFactory<BE>
68        + VecZnxAutomorphismInplace<BE>
69        + VecZnxAutomorphismInplaceTmpBytes,
70    Scratch<BE>: ScratchTakeCore<BE>,
71{
72    fn glwe_to_lwe_key_encrypt_sk_tmp_bytes<A>(&self, infos: &A) -> usize
73    where
74        A: GGLWEInfos,
75    {
76        GLWESecretPrepared::bytes_of(self, infos.rank_in())
77            + GGLWE::encrypt_sk_tmp_bytes(self, infos)
78                .max(GLWESecret::bytes_of(self.n().into(), infos.rank_in()) + self.vec_znx_automorphism_inplace_tmp_bytes())
79    }
80
81    fn glwe_to_lwe_key_encrypt_sk<R, S1, S2>(
82        &self,
83        res: &mut R,
84        sk_lwe: &S1,
85        sk_glwe: &S2,
86        source_xa: &mut Source,
87        source_xe: &mut Source,
88        scratch: &mut Scratch<BE>,
89    ) where
90        S1: LWESecretToRef,
91        S2: GLWESecretToRef,
92        R: GGLWEToMut,
93    {
94        let sk_lwe: &LWESecret<&[u8]> = &sk_lwe.to_ref();
95        let sk_glwe: &GLWESecret<&[u8]> = &sk_glwe.to_ref();
96
97        assert!(sk_lwe.n().0 <= self.n() as u32);
98
99        let (mut sk_lwe_as_glwe_prep, scratch_1) = scratch.take_glwe_secret_prepared(self, Rank(1));
100
101        {
102            let (mut sk_lwe_as_glwe, scratch_2) = scratch_1.take_glwe_secret(self.n().into(), sk_lwe_as_glwe_prep.rank());
103            sk_lwe_as_glwe.dist = sk_lwe.dist;
104            sk_lwe_as_glwe.data.zero();
105            sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n().into()].copy_from_slice(sk_lwe.data.at(0, 0));
106            self.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0, scratch_2);
107            sk_lwe_as_glwe_prep.prepare(self, &sk_lwe_as_glwe);
108        }
109
110        self.gglwe_encrypt_sk(
111            res,
112            &sk_glwe.data,
113            &sk_lwe_as_glwe_prep,
114            source_xa,
115            source_xe,
116            scratch_1,
117        );
118    }
119}
poulpy_core/encryption/glwe_to_lwe_key.rs

poulpy_core/encryption/
glwe_to_lwe_key.rs
