Squashed commit of the following:

commit 3d5f759 Author: ovi <ovi@posteo.de> Date: Fri Sep 8 17:57:46 2023 +0200 ordering ZCdpBudget commit d6a9985 Author: ovi <ovi@posteo.de> Date: Fri Sep 8 17:53:18 2023 +0200 ordering ZCdpDiscreteGaussians commit d2cdd4c Author: ovi <ovi@posteo.de> Date: Mon Sep 4 16:17:38 2023 +0200 non-pub epsilon commit cfef6a7 Author: ovi <ovi@posteo.de> Date: Mon Sep 4 15:07:01 2023 +0200 pub budget commit eae7e4e Author: ovi <ovi@posteo.de> Date: Mon Sep 4 14:32:57 2023 +0200 Display for error commit 410427e Author: ovi <ovi@posteo.de> Date: Mon Sep 4 13:53:37 2023 +0200 FromStr for Rational commit 59f5522 Author: ovi <ovi@posteo.de> Date: Sun Sep 3 14:13:20 2023 +0200 Display Rational commit 3ac128d Author: ovi <ovi@posteo.de> Date: Sun Sep 3 13:11:47 2023 +0200 trying a thing commit 42e6cad Author: ovi <ovi@posteo.de> Date: Sat Sep 2 03:07:45 2023 +0200 yet more derives commit d43961a Author: ovi <ovi@posteo.de> Date: Sat Sep 2 01:39:16 2023 +0200 yet more derives commit 76d20d9 Author: Maxim Urschumzew <u.maxim@live.de> Date: Thu Aug 31 08:59:19 2023 +0200 Add more derives. commit 7bced48 Author: Maxim Urschumzew <u.maxim@live.de> Date: Thu Aug 31 08:53:04 2023 +0200 Add derive. commit fcdc568 Author: Maxim Urschumzew <u.maxim@live.de> Date: Tue Aug 29 11:51:53 2023 +0200 Add serialize for rational. commit bd41119 Author: Maxim Urschumzew <u.maxim@live.de> Date: Sun Aug 27 18:25:33 2023 +0200 Add default impl for poplar. commit 2437364 Author: Maxim Urschumzew <u.maxim@live.de> Date: Sun Aug 27 18:21:15 2023 +0200 Add default implementations. commit 7c45460 Author: Maxim Urschumzew <u.maxim@live.de> Date: Sun Aug 27 17:47:41 2023 +0200 Add default implementation for `TypeWithNoise`. commit e5bdff3 Author: Maxim Urschumzew <u.maxim@live.de> Date: Mon Aug 14 13:34:03 2023 +0200 Add differential privacy to `FixedPointBoundedL2VecSum` (divviup#578). Co-Authored-By: Olivia <ovi@posteo.de> Co-Authored-By: Maxim Urschumzew <u.maxim@live.de>
dpsa4fl · Sep 12, 2023 · ca0a72f · ca0a72f
1 parent e2751fe
commit ca0a72f
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Showing 6 changed files with 49 additions and 5 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -22,7 +22,7 @@ hmac = { version = "0.12.1", optional = true }
 num-bigint = { version = "0.4.4", 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-rational = { version = "0.4.1", optional = true, features = ["serde"] }
 num-traits = { version = "0.2.16", optional = true }
 rand = { version = "0.8", optional = true }
 rand_core = "0.6.4"

diff --git a/src/dp.rs b/src/dp.rs
@@ -16,6 +16,8 @@
 //!
 use num_bigint::{BigInt, BigUint, TryFromBigIntError};
 use num_rational::{BigRational, Ratio};
+use serde::{Deserialize, Serialize};
+use std::{fmt, str::FromStr};
 
 /// Errors propagated by methods in this module.
 #[derive(Debug, thiserror::Error)]
@@ -38,9 +40,35 @@ pub enum DpError {
 
 /// Positive arbitrary precision rational number to represent DP and noise distribution parameters in
 /// protocol messages and manipulate them without rounding errors.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
 pub struct Rational(Ratio<BigUint>);
 
+impl fmt::Display for Rational {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+/// An error indicating a string could not be parsed as Rational.
+#[derive(Debug)]
+pub struct RationalParseError;
+
+impl fmt::Display for RationalParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "RationalParseError")
+    }
+}
+
+impl FromStr for Rational {
+    type Err = RationalParseError;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match Ratio::<BigUint>::from_str(s) {
+            Ok(r) => Ok(Rational(r)),
+            Err(_) => Err(RationalParseError),
+        }
+    }
+}
+
 impl Rational {
     /// Construct a [`Rational`] number from numerator `n` and denominator `d`. Errors if denominator is zero.
     pub fn from_unsigned<T>(n: T, d: T) -> Result<Self, DpError>
@@ -83,6 +111,7 @@ pub trait DifferentialPrivacyDistribution {}
 /// Zero-concentrated differential privacy (ZCDP) budget as defined in [[BS16]].
 ///
 /// [BS16]: https://arxiv.org/pdf/1605.02065.pdf
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, Ord, PartialOrd)]
 pub struct ZCdpBudget {
     epsilon: Ratio<BigUint>,
 }
@@ -95,6 +124,11 @@ impl ZCdpBudget {
     pub fn new(epsilon: Rational) -> Self {
         Self { epsilon: epsilon.0 }
     }
+
+    /// Return the `epsilon` parameter of this strategy.
+    pub fn get_epsilon(&self) -> Rational {
+        Rational(self.epsilon.clone())
+    }
 }
 
 impl DifferentialPrivacyBudget for ZCdpBudget {}

diff --git a/src/dp/distributions.rs b/src/dp/distributions.rs
@@ -56,6 +56,7 @@ use num_iter::range_inclusive;
 use num_rational::Ratio;
 use num_traits::{One, Zero};
 use rand::{distributions::uniform::UniformSampler, distributions::Distribution, Rng};
+use serde::{Deserialize, Serialize};
 
 use super::{
     DifferentialPrivacyBudget, DifferentialPrivacyDistribution, DifferentialPrivacyStrategy,
@@ -252,11 +253,12 @@ impl Distribution<BigInt> for DiscreteGaussian {
 impl DifferentialPrivacyDistribution for DiscreteGaussian {}
 
 /// A DP strategy using the discrete gaussian distribution.
+#[derive(Clone, PartialEq, Serialize, Deserialize, Eq, Debug, Ord, PartialOrd)]
 pub struct DiscreteGaussianDpStrategy<B>
 where
-    B: DifferentialPrivacyBudget,
+    B: DifferentialPrivacyBudget + std::fmt::Debug,
 {
-    budget: B,
+    pub budget: B,
 }
 
 /// A DP strategy using the discrete gaussian distribution providing zero-concentrated DP.

diff --git a/src/flp/types.rs b/src/flp/types.rs
@@ -2,13 +2,17 @@
 
 //! A collection of [`Type`] implementations.
 
+
+#[cfg(feature = "experimental")]
+use crate::dp::distributions::ZCdpDiscreteGaussian;
 use crate::field::{FftFriendlyFieldElement, FieldElementWithIntegerExt};
 use crate::flp::gadgets::{Mul, ParallelSumGadget, PolyEval};
 use crate::flp::{FlpError, Gadget, Type};
 use crate::polynomial::poly_range_check;
 use std::convert::TryInto;
 use std::fmt::{self, Debug};
 use std::marker::PhantomData;
+
 /// The counter data type. Each measurement is `0` or `1` and the aggregate result is the sum of the measurements (i.e., the total number of `1s`).
 #[derive(Clone, PartialEq, Eq)]
 pub struct Count<F> {
@@ -569,6 +573,7 @@ impl<F: FftFriendlyFieldElement, S> Clone for SumVec<F, S> {
     }
 }
 
+
 impl<F, S> Type for SumVec<F, S>
 where
     F: FftFriendlyFieldElement,

diff --git a/src/vdaf/poplar1.rs b/src/vdaf/poplar1.rs
@@ -12,7 +12,7 @@ use crate::{
     vdaf::{
         xof::{Seed, Xof, XofShake128},
         Aggregatable, Aggregator, Client, Collector, PrepareTransition, Vdaf, VdafError,
-    },
+    }, dp::distributions::ZCdpDiscreteGaussian,
 };
 use bitvec::{prelude::Lsb0, vec::BitVec};
 use rand_core::RngCore;
@@ -27,6 +27,8 @@ use std::{
 };
 use subtle::{Choice, ConditionallyNegatable, ConditionallySelectable, ConstantTimeEq};
 
+use super::AggregatorWithNoise;
+
 const DST_SHARD_RANDOMNESS: u16 = 1;
 const DST_CORR_INNER: u16 = 2;
 const DST_CORR_LEAF: u16 = 3;