encryption/
encryption.rs

1use poulpy_core::{
2    GLWESub, SIGMA,
3    layouts::{
4        Base2K, Degree, GLWE, GLWELayout, GLWEPlaintext, GLWEPlaintextLayout, GLWESecret, LWEInfos, Rank, TorusPrecision,
5        prepared::GLWESecretPrepared,
6    },
7};
8
9#[cfg(all(feature = "enable-avx", target_arch = "x86_64"))]
10pub use poulpy_cpu_avx::FFT64Avx as BackendImpl;
11
12#[cfg(not(all(feature = "enable-avx", target_arch = "x86_64")))]
13pub use poulpy_cpu_ref::FFT64Ref as BackendImpl;
14
15use poulpy_hal::{
16    api::{ModuleNew, ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxFillUniform},
17    layouts::{Module, ScratchOwned},
18    source::Source,
19};
20
21fn main() {
22    // Ring degree
23    let log_n: usize = 10;
24
25    let n: Degree = Degree(1 << log_n);
26
27    // Base-2-k (implicit digit decomposition)
28    let base2k: Base2K = Base2K(14);
29
30    // Ciphertext Torus precision (equivalent to ciphertext modulus)
31    let k_ct: TorusPrecision = TorusPrecision(27);
32
33    // Plaintext Torus precision (equivament to plaintext modulus)
34    let k_pt: TorusPrecision = TorusPrecision(base2k.into());
35
36    // GLWE rank
37    let rank: Rank = Rank(1);
38
39    // Instantiate Module (DFT Tables)
40    let module: Module<BackendImpl> = Module::<BackendImpl>::new(n.0 as u64);
41
42    let glwe_ct_infos: GLWELayout = GLWELayout {
43        n,
44        base2k,
45        k: k_ct,
46        rank,
47    };
48
49    let glwe_pt_infos: GLWEPlaintextLayout = GLWEPlaintextLayout { n, base2k, k: k_pt };
50
51    // Allocates ciphertext & plaintexts
52    let mut ct: GLWE<Vec<u8>> = GLWE::alloc_from_infos(&glwe_ct_infos);
53    let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc_from_infos(&glwe_pt_infos);
54    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc_from_infos(&glwe_pt_infos);
55
56    // CPRNG
57    let mut source_xs: Source = Source::new([0u8; 32]);
58    let mut source_xe: Source = Source::new([1u8; 32]);
59    let mut source_xa: Source = Source::new([2u8; 32]);
60
61    // Scratch space
62    let mut scratch: ScratchOwned<BackendImpl> = ScratchOwned::alloc(
63        GLWE::encrypt_sk_tmp_bytes(&module, &glwe_ct_infos) | GLWE::decrypt_tmp_bytes(&module, &glwe_ct_infos),
64    );
65
66    // Generate secret-key
67    let mut sk: GLWESecret<Vec<u8>> = GLWESecret::alloc_from_infos(&glwe_ct_infos);
68    sk.fill_ternary_prob(0.5, &mut source_xs);
69
70    // Backend-prepared secret
71    let mut sk_prepared: GLWESecretPrepared<Vec<u8>, BackendImpl> = GLWESecretPrepared::alloc(&module, rank);
72    sk_prepared.prepare(&module, &sk);
73
74    // Uniform plaintext
75    module.vec_znx_fill_uniform(base2k.into(), &mut pt_want.data, 0, &mut source_xa);
76
77    // Encryption
78    ct.encrypt_sk(
79        &module,
80        &pt_want,
81        &sk_prepared,
82        &mut source_xa,
83        &mut source_xe,
84        scratch.borrow(),
85    );
86
87    // Decryption
88    ct.decrypt(&module, &mut pt_have, &sk_prepared, scratch.borrow());
89
90    // Diff between pt - Dec(Enc(pt))
91    module.glwe_sub_inplace(&mut pt_want, &pt_have);
92
93    // Ideal vs. actual noise
94    let noise_have: f64 = pt_want.data.stats(base2k.into(), 0).std() * (ct.k().as_u32() as f64).exp2();
95    let noise_want: f64 = SIGMA;
96
97    // Check
98    assert!(noise_have <= noise_want + 0.2);
99}
encryption/encryption.rs

encryption/
encryption.rs
