Add differential privacy to FixedPointBoundedL2VecSum (divviup#578).

Co-Authored-By: Olivia <ovi@posteo.de> Co-Authored-By: Maxim Urschumzew <u.maxim@live.de>
dpsa4fl · Aug 25, 2023 · 81306a0 · 81306a0
1 parent d45bf21
commit 81306a0
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Showing 20 changed files with 1,488 additions and 162 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -21,6 +21,12 @@ fiat-crypto = { version = "0.1.20", optional = true }
 fixed = { version = "1.23", optional = true }
 getrandom = { version = "0.2.10", features = ["std"] }
 hmac = { version = "0.12.1", optional = true }
+num-bigint = { version = "0.4.3", optional = true, features = ["rand", "serde"] }
+num-integer = { version = "0.1.45", optional = true }
+num-iter = { version = "0.1.43", optional = true }
+num-rational = { version = "0.4.1", optional = true }
+num-traits = { version = "0.2.15", optional = true }
+rand = { version = "0.8", optional = true }
 rand_core = "0.6.4"
 rayon = { version = "1.7.0", optional = true }
 serde = { version = "1.0", features = ["derive"] }
@@ -50,7 +56,7 @@ zipf = "7.0.1"
 
 [features]
 default = ["crypto-dependencies"]
-experimental = ["bitvec", "fiat-crypto", "fixed"]
+experimental = ["bitvec", "fiat-crypto", "fixed", "num-bigint", "num-rational", "num-traits", "num-integer", "num-iter", "rand"]
 multithreaded = ["rayon"]
 prio2 = ["crypto-dependencies", "hmac", "sha2"]
 crypto-dependencies = ["aes", "ctr", "cmac"]
@@ -69,6 +75,11 @@ harness = false
 name = "cycle_counts"
 harness = false
 
+[[test]]
+name = "discrete_gauss"
+path = "tests/discrete_gauss.rs"
+required-features = ["experimental"]
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

diff --git a/benches/speed_tests.rs b/benches/speed_tests.rs
@@ -7,6 +7,16 @@ use criterion::{BatchSize, Throughput};
 use fixed::types::{I1F15, I1F31};
 #[cfg(feature = "experimental")]
 use fixed_macro::fixed;
+#[cfg(feature = "experimental")]
+use num_bigint::BigUint;
+#[cfg(feature = "experimental")]
+use num_rational::Ratio;
+#[cfg(feature = "experimental")]
+use num_traits::ToPrimitive;
+#[cfg(feature = "experimental")]
+use prio::dp::distributions::DiscreteGaussian;
+#[cfg(feature = "multithreaded")]
+use prio::flp::gadgets::ParallelSumMultithreaded;
 #[cfg(feature = "prio2")]
 use prio::vdaf::prio2::Prio2;
 use prio::{
@@ -49,6 +59,30 @@ fn prng(c: &mut Criterion) {
     group.finish();
 }
 
+/// Speed test for generating samples from the discrete gaussian distribution using different
+/// standard deviations.
+#[cfg(feature = "experimental")]
+pub fn dp_noise(c: &mut Criterion) {
+    let mut group = c.benchmark_group("dp_noise");
+    let mut rng = StdRng::seed_from_u64(RNG_SEED);
+
+    let test_stds = [
+        Ratio::<BigUint>::from_integer(BigUint::from(u128::MAX)).pow(2),
+        Ratio::<BigUint>::from_integer(BigUint::from(u64::MAX)),
+        Ratio::<BigUint>::from_integer(BigUint::from(u32::MAX)),
+        Ratio::<BigUint>::from_integer(BigUint::from(5u8)),
+        Ratio::<BigUint>::new(BigUint::from(10000u32), BigUint::from(23u32)),
+    ];
+    for std in test_stds {
+        let sampler = DiscreteGaussian::new(std.clone()).unwrap();
+        group.bench_function(
+            BenchmarkId::new("discrete_gaussian", std.to_f64().unwrap_or(f64::INFINITY)),
+            |b| b.iter(|| sampler.sample(&mut rng)),
+        );
+    }
+    group.finish();
+}
+
 /// The asymptotic cost of polynomial multiplication is `O(n log n)` using FFT and `O(n^2)` using
 /// the naive method. This benchmark demonstrates that the latter has better concrete performance
 /// for small polynomials. The result is used to pick the `FFT_THRESHOLD` constant in
@@ -312,7 +346,7 @@ fn prio3(c: &mut Criterion) {
                 BenchmarkId::new("serial", dimension),
                 &dimension,
                 |b, dimension| {
-                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _, _>, _, 16> =
+                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _>, _, 16> =
                         Prio3::new_fixedpoint_boundedl2_vec_sum(num_shares, *dimension).unwrap();
                     let mut measurement = vec![fixed!(0: I1F15); *dimension];
                     measurement[0] = fixed!(0.5: I1F15);
@@ -329,7 +363,7 @@ fn prio3(c: &mut Criterion) {
                     BenchmarkId::new("parallel", dimension),
                     &dimension,
                     |b, dimension| {
-                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _, _>, _, 16> =
+                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _>, _, 16> =
                             Prio3::new_fixedpoint_boundedl2_vec_sum_multithreaded(
                                 num_shares, *dimension,
                             )
@@ -350,7 +384,7 @@ fn prio3(c: &mut Criterion) {
                 BenchmarkId::new("series", dimension),
                 &dimension,
                 |b, dimension| {
-                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _, _>, _, 16> =
+                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _>, _, 16> =
                         Prio3::new_fixedpoint_boundedl2_vec_sum(num_shares, *dimension).unwrap();
                     let mut measurement = vec![fixed!(0: I1F15); *dimension];
                     measurement[0] = fixed!(0.5: I1F15);
@@ -379,7 +413,7 @@ fn prio3(c: &mut Criterion) {
                     BenchmarkId::new("parallel", dimension),
                     &dimension,
                     |b, dimension| {
-                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _, _>, _, 16> =
+                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F15, _, _>, _, 16> =
                             Prio3::new_fixedpoint_boundedl2_vec_sum_multithreaded(
                                 num_shares, *dimension,
                             )
@@ -413,7 +447,7 @@ fn prio3(c: &mut Criterion) {
                 BenchmarkId::new("serial", dimension),
                 &dimension,
                 |b, dimension| {
-                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _, _>, _, 16> =
+                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _>, _, 16> =
                         Prio3::new_fixedpoint_boundedl2_vec_sum(num_shares, *dimension).unwrap();
                     let mut measurement = vec![fixed!(0: I1F31); *dimension];
                     measurement[0] = fixed!(0.5: I1F31);
@@ -430,7 +464,7 @@ fn prio3(c: &mut Criterion) {
                     BenchmarkId::new("parallel", dimension),
                     &dimension,
                     |b, dimension| {
-                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _, _>, _, 16> =
+                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _>, _, 16> =
                             Prio3::new_fixedpoint_boundedl2_vec_sum_multithreaded(
                                 num_shares, *dimension,
                             )
@@ -451,7 +485,7 @@ fn prio3(c: &mut Criterion) {
                 BenchmarkId::new("series", dimension),
                 &dimension,
                 |b, dimension| {
-                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _, _>, _, 16> =
+                    let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _>, _, 16> =
                         Prio3::new_fixedpoint_boundedl2_vec_sum(num_shares, *dimension).unwrap();
                     let mut measurement = vec![fixed!(0: I1F31); *dimension];
                     measurement[0] = fixed!(0.5: I1F31);
@@ -480,7 +514,7 @@ fn prio3(c: &mut Criterion) {
                     BenchmarkId::new("parallel", dimension),
                     &dimension,
                     |b, dimension| {
-                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _, _>, _, 16> =
+                        let vdaf: Prio3<FixedPointBoundedL2VecSum<I1F31, _, _>, _, 16> =
                             Prio3::new_fixedpoint_boundedl2_vec_sum_multithreaded(
                                 num_shares, *dimension,
                             )
@@ -737,9 +771,26 @@ fn poplar1_generate_zipf_distributed_batch(
 }
 
 #[cfg(all(feature = "prio2", feature = "experimental"))]
-criterion_group!(benches, poplar1, prio3, prio2, poly_mul, prng, idpf);
+criterion_group!(
+    benches,
+    poplar1,
+    prio3,
+    prio2,
+    poly_mul,
+    prng,
+    idpf,
+    dp_noise
+);
 #[cfg(all(not(feature = "prio2"), feature = "experimental"))]
-criterion_group!(benches, poplar1, prio3, poly_mul, prng, idpf);
+criterion_group!(
+    benches,
+    poplar1,
+    prio3,
+    poly_mul,
+    prng,
+    idpf,
+    dp_noise
+);
 #[cfg(all(feature = "prio2", not(feature = "experimental")))]
 criterion_group!(benches, prio3, prio2, prng, poly_mul);
 #[cfg(all(not(feature = "prio2"), not(feature = "experimental")))]

diff --git a/binaries/src/bin/vdaf_message_sizes.rs b/binaries/src/bin/vdaf_message_sizes.rs
@@ -1,5 +1,6 @@
 use fixed::{types::extra::U15, FixedI16};
 use fixed_macro::fixed;
+
 use prio::{
     codec::Encode,
     vdaf::{