Update READMEs & add SECURITY.md (#78)

poulpy-core/examples/encryption.rs

@@ -0,0 +1,84 @@
+use poulpy_backend::cpu_spqlios::FFT64;
+use poulpy_core::{
+    GLWEOperations, SIGMA,
+    layouts::{
+        GLWECiphertext, GLWEPlaintext, GLWESecret, Infos,
+        prepared::{GLWESecretPrepared, PrepareAlloc},
+    },
+};
+use poulpy_hal::{
+    api::{ModuleNew, ScratchOwnedAlloc, ScratchOwnedBorrow, VecZnxFillUniform},
+    layouts::{Module, ScratchOwned},
+    source::Source,
+};
+
+fn main() {
+    // Ring degree
+    let log_n: usize = 10;
+
+    let n: usize = 1 << log_n;
+
+    // Base-2-k (implicit digit decomposition)
+    let basek: usize = 14;
+
+    // Ciphertext Torus precision (equivalent to ciphertext modulus)
+    let k_ct: usize = 27;
+
+    // Plaintext Torus precision (equivament to plaintext modulus)
+    let k_pt: usize = basek;
+
+    // GLWE rank
+    let rank: usize = 1;
+
+    // Instantiate Module (DFT Tables)
+    let module: Module<FFT64> = Module::<FFT64>::new(n as u64);
+
+    // Allocates ciphertext & plaintexts
+    let mut ct: GLWECiphertext<Vec<u8>> = GLWECiphertext::alloc(n, basek, k_ct, rank);
+    let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(n, basek, k_pt);
+    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::alloc(n, basek, k_pt);
+
+    // CPRNG
+    let mut source_xs: Source = Source::new([0u8; 32]);
+    let mut source_xe: Source = Source::new([1u8; 32]);
+    let mut source_xa: Source = Source::new([2u8; 32]);
+
+    // Scratch space
+    let mut scratch: ScratchOwned<FFT64> = ScratchOwned::alloc(
+        GLWECiphertext::encrypt_sk_scratch_space(&module, n, basek, ct.k())
+            | GLWECiphertext::decrypt_scratch_space(&module, n, basek, ct.k()),
+    );
+
+    // Generate secret-key
+    let mut sk: GLWESecret<Vec<u8>> = GLWESecret::alloc(n, rank);
+    sk.fill_ternary_prob(0.5, &mut source_xs);
+
+    // Backend-prepared secret
+    let sk_prepared: GLWESecretPrepared<Vec<u8>, FFT64> = sk.prepare_alloc(&module, scratch.borrow());
+
+    // Uniform plaintext
+    module.vec_znx_fill_uniform(basek, &mut pt_want.data, 0, k_pt, &mut source_xa);
+
+    // Encryption
+    ct.encrypt_sk(
+        &module,
+        &pt_want,
+        &sk_prepared,
+        &mut source_xa,
+        &mut source_xe,
+        scratch.borrow(),
+    );
+
+    // Decryption
+    ct.decrypt(&module, &mut pt_have, &sk_prepared, scratch.borrow());
+
+    // Diff between pt - Dec(Enc(pt))
+    pt_want.sub_inplace_ab(&module, &pt_have);
+
+    // Ideal vs. actual noise
+    let noise_have: f64 = pt_want.data.std(basek, 0) * (ct.k() as f64).exp2();
+    let noise_want: f64 = SIGMA;
+
+    // Check
+    assert!(noise_have <= noise_want + 0.2);
+}