1use backend::hal::{
 2    api::{
 3        ScratchAvailable, SvpApplyInplace, SvpPPolAllocBytes, SvpPrepare, TakeScalarZnx, TakeVecZnx, TakeVecZnxDft,
 4        VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace, VecZnxAutomorphismInplace, VecZnxBigNormalize,
 5        VecZnxDftAllocBytes, VecZnxDftFromVecZnx, VecZnxDftToVecZnxBigConsume, VecZnxFillUniform, VecZnxNormalize,
 6        VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubABInplace, VecZnxSwithcDegree, ZnxView, ZnxViewMut,
 7        ZnxZero,
 8    },
 9    layouts::{Backend, DataMut, DataRef, Module, Scratch},
10};
11use sampling::source::Source;
12
13use crate::{
14    TakeGLWESecret, TakeGLWESecretPrepared,
15    layouts::{GGLWESwitchingKey, GLWESecret, GLWEToLWESwitchingKey, LWESecret, prepared::GLWESecretPrepared},
16};
17
18impl GLWEToLWESwitchingKey<Vec<u8>> {
19    pub fn encrypt_sk_scratch_space<B: Backend>(module: &Module<B>, n: usize, basek: usize, k: usize, rank_in: usize) -> usize
20    where
21        Module<B>: SvpPPolAllocBytes + VecZnxNormalizeTmpBytes + VecZnxDftAllocBytes + VecZnxNormalizeTmpBytes,
22    {
23        GLWESecretPrepared::bytes_of(module, n, rank_in)
24            + (GGLWESwitchingKey::encrypt_sk_scratch_space(module, n, basek, k, rank_in, 1) | GLWESecret::bytes_of(n, rank_in))
25    }
26}
27
28impl<D: DataMut> GLWEToLWESwitchingKey<D> {
29    pub fn encrypt_sk<DLwe, DGlwe, B: Backend>(
30        &mut self,
31        module: &Module<B>,
32        sk_lwe: &LWESecret<DLwe>,
33        sk_glwe: &GLWESecret<DGlwe>,
34        source_xa: &mut Source,
35        source_xe: &mut Source,
36        sigma: f64,
37        scratch: &mut Scratch<B>,
38    ) where
39        DLwe: DataRef,
40        DGlwe: DataRef,
41        Module<B>: VecZnxAutomorphismInplace
42            + VecZnxAddScalarInplace
43            + VecZnxDftAllocBytes
44            + VecZnxBigNormalize<B>
45            + VecZnxDftFromVecZnx<B>
46            + SvpApplyInplace<B>
47            + VecZnxDftToVecZnxBigConsume<B>
48            + VecZnxNormalizeTmpBytes
49            + VecZnxFillUniform
50            + VecZnxSubABInplace
51            + VecZnxAddInplace
52            + VecZnxNormalizeInplace<B>
53            + VecZnxAddNormal
54            + VecZnxNormalize<B>
55            + VecZnxSub
56            + SvpPrepare<B>
57            + VecZnxSwithcDegree
58            + SvpPPolAllocBytes,
59        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx + TakeScalarZnx + TakeGLWESecretPrepared<B>,
60    {
61        #[cfg(debug_assertions)]
62        {
63            assert!(sk_lwe.n() <= module.n());
64        }
65
66        let (mut sk_lwe_as_glwe, scratch1) = scratch.take_glwe_secret(sk_glwe.n(), 1);
67        sk_lwe_as_glwe.data.zero();
68        sk_lwe_as_glwe.data.at_mut(0, 0)[..sk_lwe.n()].copy_from_slice(sk_lwe.data.at(0, 0));
69        module.vec_znx_automorphism_inplace(-1, &mut sk_lwe_as_glwe.data.as_vec_znx_mut(), 0);
70
71        self.0.encrypt_sk(
72            module,
73            sk_glwe,
74            &sk_lwe_as_glwe,
75            source_xa,
76            source_xe,
77            sigma,
78            scratch1,
79        );
80    }
81}