Performance Optimizations (#5)

Enabling Lazy NTT, giving a speedup of about 2x for encryption/decryption/rerandomization. 

* Updated version to 0.2.0

* added poly operation benchmarks

* added butterfly mod and tests

* cleaned up interfaces.

* basic lazy butterfly tests work

* lazy butterfly and tests

* added trait and tests for lazy transforms

* swap

* switch to use split_at

* added lazy (i)ntt; tests pass.

* conditional compilation

* benchmarking

* optimized performance by pure u64 impl

* added benchmark for integer ops and gaussian sampling

* sample ternary

* optimized uniform sampling

* clean up

* enabled lazy ntt by default

* fixing reviewer comments

* fix underflow

* further addressing comments

* updating version to 0.2.1

* remove unused dependencies

Co-authored-by: Hao Chen <sxxach@gmail.com>

.gitignore

@@ -1,2 +1,3 @@
 /target
 Cargo.lock
+src/*.md

CHANGELOG.md

@@ -0,0 +1,8 @@
+## 0.2.1 (August 30, 2021)
+
+* Performance optimizations: Faster encryption/decryption based on lazy NTT
+
+## 0.2.0 (June 1, 2021)
+
+* Added serailization support
+* Added ability to customize plaintext modulus

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "Cupcake"
-version = "0.1.1"
+version = "0.2.1"
 authors = ["Hao Chen <haoche@fb.com>"]
 license = "MIT"
 edition = "2018"
@@ -20,12 +20,28 @@ bencher = "0.1.5"
 name = "cupcake"
 path = "src/lib.rs"
 
+[features]
+bench = []
+
 [[example]]
 name = "basic"
 
 [[example]]
 name = "serialization"
 
 [[bench]]
-name = "example"
+name = "scheme"
+harness = false
+
+[[bench]]
+name = "polyops"
+harness = false
+required-features = ["bench"]
+
+[[bench]]
+name = "butterfly"
+harness = false
+
+[[bench]]
+name = "integerops"
 harness = false

README.md

@@ -11,7 +11,7 @@ Cupcake requires or works with
 ## Installation
 Add the following line to the dependencies of your Cargo.toml:
 ```
-Cupcake = "0.1.1"
+Cupcake = "0.2.1"
 ```
 
 ## Building from source

benches/butterfly.rs

@@ -0,0 +1,73 @@
+// Copyright (c) Facebook, Inc. and its affiliates.
+//
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+#[macro_use]
+extern crate bencher;
+use bencher::Bencher;
+use cupcake::integer_arith::butterfly::{
+    butterfly, inverse_butterfly, lazy_butterfly, lazy_butterfly_u64,
+};
+use cupcake::integer_arith::scalar::Scalar;
+use cupcake::integer_arith::ArithUtils;
+
+#[allow(non_snake_case)]
+fn bench_butterfly(bench: &mut Bencher) {
+    let q = Scalar::new_modulus(18014398492704769u64);
+    let x = rand::random::<u64>();
+    let y = rand::random::<u64>();
+    let w = rand::random::<u64>();
+
+    let mut X = Scalar::from(x);
+    let mut Y = Scalar::from(y);
+    let W = Scalar::from(w);
+
+    bench.iter(|| {
+        let _ = butterfly(&mut X, &mut Y, &W, &q);
+    })
+}
+
+#[allow(non_snake_case)]
+fn bench_inverse_butterfly(bench: &mut Bencher) {
+    let q = Scalar::new_modulus(18014398492704769u64);
+    let x = rand::random::<u64>();
+    let y = rand::random::<u64>();
+    let w = rand::random::<u64>();
+
+    let mut X = Scalar::from(x);
+    let mut Y = Scalar::from(y);
+    let W = Scalar::from(w);
+
+    bench.iter(|| {
+        let _ = inverse_butterfly(&mut X, &mut Y, &W, &q);
+    })
+}
+
+#[allow(non_snake_case)]
+fn bench_lazy_butterfly(bench: &mut Bencher) {
+    let q = Scalar::new_modulus(18014398492704769u64);
+    let x = rand::random::<u64>();
+    let y = rand::random::<u64>();
+    let w = rand::random::<u64>();
+
+    let mut X = Scalar::from(x);
+    let mut Y = Scalar::from(y);
+    let W = Scalar::from(w);
+
+    let Wprime: u64 = cupcake::integer_arith::util::compute_harvey_ratio(W.rep(), q.rep());
+
+    let twoq: u64 = q.rep() << 1;
+
+    bench.iter(|| {
+        let _ = lazy_butterfly_u64(x, y, W.rep(), Wprime, q.rep(), twoq);
+    })
+}
+
+benchmark_group!(
+    butterfly_group,
+    bench_butterfly,
+    bench_inverse_butterfly,
+    bench_lazy_butterfly
+);
+
+benchmark_main!(butterfly_group);