arnaucube/poulpy
1
0
Fork 0
mirror of https://github.com/arnaucube/poulpy.git synced 2026-02-10 13:16:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Updated arguments to get scratch space size for ops

Browse Source
This commit is contained in:
Jean-Philippe Bossuat
2025-05-28 18:46:24 +02:00
parent 8209fb4e40
commit f9440c5407
20 changed files with 599 additions and 529 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
core/src/glwe_packing.rs
View File

@@ -1,7 +1,7 @@
use crate::{ScratchCore, automorphism::AutomorphismKey, elem::Infos, glwe_ciphertext::GLWECiphertext, glwe_ops::GLWEOps};
use std::collections::HashMap;
use backend::{FFT64, Module, Scratch, VecZnxAlloc};
use backend::{FFT64, Module, Scratch};
/// [StreamPacker] enables only the fly GLWE packing
/// with constant memory of Log(N) ciphertexts.
@@ -74,8 +74,8 @@ impl StreamPacker {
}
/// Number of scratch space bytes required to call [Self::add].
pub fn scratch_space(module: &Module<FFT64>, ct_size: usize, autokey_size: usize, rank: usize) -> usize {
pack_core_scratch_space(module, ct_size, autokey_size, rank)
pub fn scratch_space(module: &Module<FFT64>, basek: usize, ct_k: usize, atk_k: usize, rank: usize) -> usize {
pack_core_scratch_space(module, basek, ct_k, atk_k, rank)
}
pub fn galois_elements(module: &Module<FFT64>) -> Vec<i64> {
@@ -142,8 +142,8 @@ impl StreamPacker {
}
}
fn pack_core_scratch_space(module: &Module<FFT64>, ct_size: usize, autokey_size: usize, rank: usize) -> usize {
combine_scratch_space(module, ct_size, autokey_size, rank)
fn pack_core_scratch_space(module: &Module<FFT64>, basek: usize, ct_k: usize, atk_k: usize, rank: usize) -> usize {
combine_scratch_space(module, basek, ct_k, atk_k, rank)
}
fn pack_core<D: AsRef<[u8]>, DataAK: AsRef<[u8]>>(
@@ -203,10 +203,10 @@ fn pack_core<D: AsRef<[u8]>, DataAK: AsRef<[u8]>>(
}
}
fn combine_scratch_space(module: &Module<FFT64>, ct_size: usize, autokey_size: usize, rank: usize) -> usize {
2 * module.bytes_of_vec_znx(rank + 1, ct_size)
fn combine_scratch_space(module: &Module<FFT64>, basek: usize, ct_k: usize, atk_k: usize, rank: usize) -> usize {
GLWECiphertext::bytes_of(module, basek, ct_k, rank)
+ (GLWECiphertext::rsh_scratch_space(module)
| GLWECiphertext::automorphism_scratch_space(module, ct_size, rank, ct_size, autokey_size))
| GLWECiphertext::automorphism_scratch_space(module, basek, ct_k, ct_k, atk_k, rank))
}
/// [combine] merges two ciphertexts together.
@@ -232,46 +232,52 @@ fn combine<D: AsRef<[u8]>, DataAK: AsRef<[u8]>>(
gal_el = module.galois_element(1 << (i - 1))
}
// Goal is to evaluate: a = a + b*X^t + phi(a - b*X^t)) X^t(a*X^-t + b - phi(a*X^-t + b))
// Different cases for wether a and/or b are zero.
if acc.value {
// Implicite RSH without modulus switch, introduces extra I(X) * Q/2 on decryption.
// Necessary so that the scaling of the plaintext remains constant.
// It however is ok to do so here because coefficients are eventually
// either mapped to garbage or twice their value which vanishes I(X)
// since 2*(I(X) * Q/2) = I(X) * Q = 0 mod Q.
a.rsh(1, scratch);
let t: i64 = 1 << (log_n - i - 1);
// Goal is to evaluate: a = a + b*X^t + phi(a - b*X^t))
// We also use the identity: AUTO(a * X^t, g) = -X^t * AUTO(a, g)
// where t = 2^(log_n - i - 1) and g = 5^{2^(i - 1)}
// Different cases for wether a and/or b are zero.
//
// Implicite RSH without modulus switch, introduces extra I(X) * Q/2 on decryption.
// Necessary so that the scaling of the plaintext remains constant.
// It however is ok to do so here because coefficients are eventually
// either mapped to garbage or twice their value which vanishes I(X)
// since 2*(I(X) * Q/2) = I(X) * Q = 0 mod Q.
if acc.value {
if let Some(b) = b {
let (mut tmp_b, scratch_1) = scratch.tmp_glwe_ct(module, basek, k, rank);
{
let (mut tmp_a, scratch_2) = scratch_1.tmp_glwe_ct(module, basek, k, rank); //TODO can we skip tmp_a by reordering X^k ?
// tmp_a = b * X^t
tmp_a.rotate(module, 1 << (log_n - i - 1), b);
// a = a * X^-t
a.rotate_inplace(module, -t);
// tmp_a >>= 1
tmp_a.rsh(1, scratch_2);
// tmp_b = a * X^-t - b
tmp_b.sub(module, a, b);
tmp_b.rsh(1, scratch_1);
// tmp_b = a - b*X^t
tmp_b.sub(module, a, &tmp_a);
tmp_b.normalize_inplace(module, scratch_2);
// a = a * X^-t + b
a.add_inplace(module, b);
a.rsh(1, scratch_1);
// a = a + b * X^t
a.add_inplace(module, &tmp_a);
}
tmp_b.normalize_inplace(module, scratch_1);
// tmp_b = phi(a - b * X^t)
// tmp_b = phi(a * X^-t - b)
if let Some(key) = auto_keys.get(&gal_el) {
tmp_b.automorphism_inplace(module, key, scratch_1);
} else {
panic!("auto_key[{}] not found", gal_el);
}
// a = a + b*X^t + phi(a - b*X^t))
a.add_inplace(module, &tmp_b);
// a = a * X^-t + b - phi(a * X^-t - b)
a.sub_inplace_ab(module, &tmp_b);
a.normalize_inplace(module, scratch_1);
// a = a + b * X^t - phi(a * X^-t - b) * X^t
// = a + b * X^t - phi(a * X^-t - b) * - phi(X^t)
// = a + b * X^t + phi(a - b * X^t)
a.rotate_inplace(module, t);
} else {
a.rsh(1, scratch);
// a = a + phi(a)
if let Some(key) = auto_keys.get(&gal_el) {
a.automorphism_add_inplace(module, key, scratch);