module_lwe/
keygen.rs

1use polynomial_ring::Polynomial;
2use std::collections::HashMap;
3use crate::utils::{Parameters, add_vec, mul_mat_vec_simple, gen_small_vector, gen_uniform_matrix,compress};
4
5/// Generate public and secret keys for the ring-LWE cryptosystem
6/// # Arguments
7/// * `params` - Parameters for the ring-LWE cryptosystem
8/// * `seed` - random seed
9/// # Returns
10/// * `((a, t), sk)` - public key (a, t) and secret key (sk)
11/// # Example
12/// ```
13/// let params = module_lwe::utils::Parameters::default();
14/// let (pk, sk) = module_lwe::keygen::keygen(&params, None);
15/// ```
16pub fn keygen(
17	params: &Parameters,
18    seed: Option<u64> //random seed
19) -> ((Vec<Vec<Polynomial<i64>>>, Vec<Polynomial<i64>>), Vec<Polynomial<i64>>) {
20    let (n,q,k,f,omega) = (params.n, params.q, params.k, &params.f, params.omega);
21    //Generate a public and secret key
22    let a = gen_uniform_matrix(n, k, q, seed);
23    let sk = gen_small_vector(n, k, seed);
24    let e = gen_small_vector(n, k, seed);
25    let t = add_vec(&mul_mat_vec_simple(&a, &sk, q, &f, omega), &e, q, &f);
26    
27    //Return public key (a, t) and secret key (sk) as a 2-tuple
28    ((a, t), sk)
29}
30
31/// Generate public and secret keys for the ring-LWE cryptosystem and return them as a HashMap
32/// They are serialized and base64 encoded
33/// # Arguments
34/// * `params` - Parameters for the ring-LWE cryptosystem
35/// * `seed` - random seed
36/// # Returns
37/// * `keys` - HashMap containing the public and secret keys as base64 encoded strings
38/// # Example
39/// ```
40/// let params = module_lwe::utils::Parameters::default();
41/// let keys = module_lwe::keygen::keygen_string(&params, None);
42/// ```
43pub fn keygen_string(params: &Parameters, seed: Option<u64>) -> HashMap<String, String> {
44    // Generate public and secret keys
45    let (pk, sk) = keygen(params, seed);
46
47    // Convert the public key to a flattened list of coefficients
48    let mut pk_coeffs: Vec<i64> = pk.0
49        .iter()
50        .flat_map(|row| {
51            row.iter().flat_map(|poly| {
52                let mut coeffs = poly.coeffs().to_vec();
53                coeffs.resize(params.n, 0); // Resize to include leading zeros up to size `n`
54                coeffs
55            })
56        })
57        .collect();
58
59    pk_coeffs.extend(
60        pk.1.iter()
61        .flat_map(|poly| {
62            let mut coeffs = poly.coeffs().to_vec();
63            coeffs.resize(params.n, 0); // Resize to include leading zeros up to size `n`
64            coeffs
65        })
66    );
67
68    // Convert the secret key to a flattened list of coefficients
69    let sk_coeffs: Vec<i64> = sk
70        .iter()
71        .flat_map(|poly| {
72            let mut coeffs = poly.coeffs().to_vec();
73            coeffs.resize(params.n, 0); // Resize to include leading zeros up to size `n`
74            coeffs
75        })
76    .collect();
77
78    // Store the Base64 encoded keys in a HashMap
79    let mut keys: HashMap<String, String> = HashMap::new();
80    keys.insert(String::from("secret"), compress(&sk_coeffs));
81    keys.insert(String::from("public"), compress(&pk_coeffs));
82
83    keys
84}
module_lwe/keygen.rs

module_lwe/
keygen.rs
