Merge pull request #60 from qfall/psf_perturbation

PSF with Perturbation Sampling

Author: jnsiemer

benches/benchmarks.rs

@@ -10,6 +10,7 @@
 use criterion::criterion_main;
 
 pub mod pfdh;
+pub mod psf;
 pub mod regev;
 
-criterion_main! {regev::benches, pfdh::benches}
+criterion_main! {regev::benches, pfdh::benches, psf::benches}

benches/psf.rs

@@ -0,0 +1,100 @@
+// Copyright © 2025 Niklas Siemer
+//
+// This file is part of qFALL-crypto.
+//
+// qFALL-crypto is free software: you can redistribute it and/or modify it under
+// the terms of the Mozilla Public License Version 2.0 as published by the
+// Mozilla Foundation. See <https://mozilla.org/en-US/MPL/2.0/>.
+
+use criterion::{criterion_group, Criterion};
+use qfall_crypto::{
+    primitive::psf::{PSFPerturbation, PSF, PSFGPV},
+    sample::g_trapdoor::gadget_parameters::GadgetParameters,
+};
+use qfall_math::{integer_mod_q::MatZq, rational::Q};
+
+/// Benchmark [bench_psf] with `n = 8`.
+///
+/// This benchmark can be run with for example:
+/// - `cargo criterion PSF\ GPV\ n=8`
+/// - `cargo bench --bench benchmarks PSF\ GPV\ n=8`
+/// - `cargo flamegraph --bench benchmarks -- --bench PSF\ GPV\ n=8`
+///
+/// Shorter variants or regex expressions can also be used to specify the
+/// benchmark name. The `\ ` is used to escape the space, alternatively,
+/// quotation marks can be used.
+fn bench_psf(c: &mut Criterion) {
+    let (n, q) = (8, 128);
+
+    let psf = PSFGPV {
+        gp: GadgetParameters::init_default(n, q),
+        // multiply with the rounding parameter from next test to have the same samplign parameter
+        s: Q::from(30) * Q::from(n).log(2).unwrap(),
+    };
+
+    let target = MatZq::sample_uniform(n, 1, q);
+    let (a, r) = psf.trap_gen();
+
+    c.bench_function("PSF GPV n=8", |b| b.iter(|| psf.samp_p(&a, &r, &target)));
+}
+
+/// Benchmark [bench_psf_perturbation] with `n = 8`.
+///
+/// This benchmark can be run with for example:
+/// - `cargo criterion PSF\ Perturbation\ n=8`
+/// - `cargo bench --bench benchmarks PSF\ Perturbation\ n=8`
+/// - `cargo flamegraph --bench benchmarks -- --bench PSF\ Perturbation\ n=8`
+///
+/// Shorter variants or regex expressions can also be used to specify the
+/// benchmark name. The `\ ` is used to escape the space, alternatively,
+/// quotation marks can be used.
+fn bench_psf_perturbation(c: &mut Criterion) {
+    let (n, q) = (8, 128);
+
+    let psf = PSFPerturbation {
+        gp: GadgetParameters::init_default(n, q),
+        s: Q::from(30),
+        r: Q::from(n).log(2).unwrap(),
+    };
+
+    let target = MatZq::sample_uniform(n, 1, q);
+    let (a, r) = psf.trap_gen();
+
+    c.bench_function("PSF Perturbation n=8", |b| {
+        b.iter(|| psf.samp_p(&a, &r, &target))
+    });
+}
+
+/// Benchmark [bench_psf_perturbation] with `n = 64`.
+///
+/// This benchmark can be run with for example:
+/// - `cargo criterion PSF\ Perturbation\ n=64`
+/// - `cargo bench --bench benchmarks PSF\ Perturbation\ n=64`
+/// - `cargo flamegraph --bench benchmarks -- --bench PSF\ Perturbation\ n=64`
+///
+/// Shorter variants or regex expressions can also be used to specify the
+/// benchmark name. The `\ ` is used to escape the space, alternatively,
+/// quotation marks can be used.
+fn bench_psf_perturbation_larger(c: &mut Criterion) {
+    let (n, q) = (64, 128);
+
+    let psf = PSFPerturbation {
+        gp: GadgetParameters::init_default(n, q),
+        s: Q::from(100),
+        r: Q::from(n).log(2).unwrap(),
+    };
+
+    let target = MatZq::sample_uniform(n, 1, q);
+    let (a, r) = psf.trap_gen();
+
+    c.bench_function("PSF Perturbation n=64", |b| {
+        b.iter(|| psf.samp_p(&a, &r, &target))
+    });
+}
+
+criterion_group!(
+    benches,
+    bench_psf,
+    bench_psf_perturbation,
+    bench_psf_perturbation_larger,
+);

src/primitive/psf.rs

@@ -20,12 +20,18 @@
 //!   January. Implementation and evaluation of improved Gaussian sampling for lattice
 //!   trapdoors. In Proceedings of the 6th Workshop on Encrypted Computing & Applied
 //!   Homomorphic Cryptography (pp. 61-71). <https://dl.acm.org/doi/pdf/10.1145/3267973.3267975>
+//! - \[3\] Peikert, Chris.
+//!   An efficient and parallel Gaussian sampler for lattices.
+//!   In: Annual Cryptology Conference - CRYPTO 2010.
+//!   Springer, Berlin, Heidelberg. <https://doi.org/10.1007/978-3-642-14623-7_5>
 
 mod gpv;
 mod gpv_ring;
+mod mp_perturbation;
 
 pub use gpv::PSFGPV;
 pub use gpv_ring::PSFGPVRing;
+pub use mp_perturbation::PSFPerturbation;
 
 /// This trait should be implemented by all constructions that are
 /// actual implementations of a preimage sampleable function.