poulpy_core/layouts/
glwe_to_lwe_key.rs

1use poulpy_hal::{
2    layouts::{Backend, Data, FillUniform, HostDataMut, HostDataRef, ReaderFrom, WriterTo},
3    source::Source,
4};
5
6use crate::{
7    DeclaredK,
8    layouts::{
9        Base2K, Degree, Dnum, Dsize, GGLWEAtViewMut, GGLWEAtViewRef, GGLWEBackendMut, GGLWEBackendRef, GGLWEInfos,
10        GGLWEToBackendMut, GGLWEToBackendRef, GLWEInfos, GLWESwitchingKey, GLWESwitchingKeyDegrees, GLWESwitchingKeyDegreesMut,
11        GLWEViewMut, GLWEViewRef, LWEInfos, Rank, TorusPrecision,
12    },
13};
14
15use std::fmt;
16
17#[derive(PartialEq, Eq, Copy, Clone, Debug)]
18pub struct GLWEToLWEKeyLayout {
19    pub n: Degree,
20    pub base2k: Base2K,
21    pub k: TorusPrecision,
22    pub rank_in: Rank,
23    pub dnum: Dnum,
24}
25
26impl DeclaredK for GLWEToLWEKeyLayout {
27    fn k(&self) -> TorusPrecision {
28        self.k
29    }
30}
31
32impl LWEInfos for GLWEToLWEKeyLayout {
33    fn n(&self) -> Degree {
34        self.n
35    }
36
37    fn base2k(&self) -> Base2K {
38        self.base2k
39    }
40
41    fn size(&self) -> usize {
42        self.k.as_usize().div_ceil(self.base2k.as_usize())
43    }
44}
45
46impl GLWEInfos for GLWEToLWEKeyLayout {
47    fn rank(&self) -> Rank {
48        self.rank_out()
49    }
50}
51
52impl GGLWEInfos for GLWEToLWEKeyLayout {
53    fn rank_in(&self) -> Rank {
54        self.rank_in
55    }
56
57    fn dsize(&self) -> Dsize {
58        Dsize(1)
59    }
60
61    fn rank_out(&self) -> Rank {
62        Rank(1)
63    }
64
65    fn dnum(&self) -> Dnum {
66        self.dnum
67    }
68}
69
70/// A special [`GLWESwitchingKey`] required for the conversion from `GLWE` to `LWE`.
71#[derive(PartialEq, Eq, Clone)]
72pub struct GLWEToLWEKey<D: Data>(pub(crate) GLWESwitchingKey<D>);
73
74impl<D: Data> LWEInfos for GLWEToLWEKey<D> {
75    fn base2k(&self) -> Base2K {
76        self.0.base2k()
77    }
78
79    fn n(&self) -> Degree {
80        self.0.n()
81    }
82
83    fn size(&self) -> usize {
84        self.0.size()
85    }
86}
87
88impl<D: Data> GLWEInfos for GLWEToLWEKey<D> {
89    fn rank(&self) -> Rank {
90        self.rank_out()
91    }
92}
93impl<D: Data> GGLWEInfos for GLWEToLWEKey<D> {
94    fn rank_in(&self) -> Rank {
95        self.0.rank_in()
96    }
97
98    fn dsize(&self) -> Dsize {
99        self.0.dsize()
100    }
101
102    fn rank_out(&self) -> Rank {
103        self.0.rank_out()
104    }
105
106    fn dnum(&self) -> Dnum {
107        self.0.dnum()
108    }
109}
110
111impl<D: HostDataRef> fmt::Debug for GLWEToLWEKey<D> {
112    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
113        write!(f, "{self}")
114    }
115}
116
117impl<D: HostDataMut> FillUniform for GLWEToLWEKey<D> {
118    fn fill_uniform(&mut self, log_bound: usize, source: &mut Source) {
119        self.0.fill_uniform(log_bound, source);
120    }
121}
122
123impl<D: HostDataRef> fmt::Display for GLWEToLWEKey<D> {
124    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
125        write!(f, "(GLWEToLWEKey) {}", self.0)
126    }
127}
128
129impl<D: HostDataMut> ReaderFrom for GLWEToLWEKey<D> {
130    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
131        self.0.read_from(reader)
132    }
133}
134
135impl<D: HostDataRef> WriterTo for GLWEToLWEKey<D> {
136    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
137        self.0.write_to(writer)
138    }
139}
140
141#[expect(
142    dead_code,
143    reason = "host-owned constructors are kept for serialization and host-only staging"
144)]
145impl GLWEToLWEKey<Vec<u8>> {
146    pub(crate) fn alloc_from_infos<A>(infos: &A) -> Self
147    where
148        A: GGLWEInfos,
149    {
150        assert_eq!(infos.rank_out().0, 1, "rank_out > 1 is not supported for GLWEToLWEKey");
151        assert_eq!(infos.dsize().0, 1, "dsize > 1 is not supported for GLWEToLWEKey");
152        Self::alloc(infos.n(), infos.base2k(), infos.max_k(), infos.rank_in(), infos.dnum())
153    }
154
155    pub(crate) fn alloc(n: Degree, base2k: Base2K, k: TorusPrecision, rank_in: Rank, dnum: Dnum) -> Self {
156        GLWEToLWEKey(GLWESwitchingKey::alloc(n, base2k, k, rank_in, Rank(1), dnum, Dsize(1)))
157    }
158
159    pub fn bytes_of_from_infos<A>(infos: &A) -> usize
160    where
161        A: GGLWEInfos,
162    {
163        assert_eq!(infos.rank_out().0, 1, "rank_out > 1 is not supported for GLWEToLWEKey");
164        assert_eq!(infos.dsize().0, 1, "dsize > 1 is not supported for GLWEToLWEKey");
165        Self::bytes_of(infos.n(), infos.base2k(), infos.max_k(), infos.rank_in(), infos.dnum())
166    }
167
168    pub fn bytes_of(n: Degree, base2k: Base2K, k: TorusPrecision, rank_in: Rank, dnum: Dnum) -> usize {
169        GLWESwitchingKey::bytes_of(n, base2k, k, rank_in, Rank(1), dnum, Dsize(1))
170    }
171}
172
173impl_gglwe_to_backend_for_field!(GLWEToLWEKey<D>, 0, GLWESwitchingKey<D>);
174
175impl_gglwe_at_view_for_field!(GLWEToLWEKey<BE::OwnedBuf>; 0.key);
176
177impl<D: HostDataMut> GLWESwitchingKeyDegreesMut for GLWEToLWEKey<D> {
178    fn input_degree(&mut self) -> &mut Degree {
179        &mut self.0.input_degree
180    }
181
182    fn output_degree(&mut self) -> &mut Degree {
183        &mut self.0.output_degree
184    }
185}
186
187impl<D: HostDataRef> GLWESwitchingKeyDegrees for GLWEToLWEKey<D> {
188    fn input_degree(&self) -> &Degree {
189        &self.0.input_degree
190    }
191
192    fn output_degree(&self) -> &Degree {
193        &self.0.output_degree
194    }
195}
poulpy_core/layouts/glwe_to_lwe_key.rs

poulpy_core/layouts/
glwe_to_lwe_key.rs
