Merge pull request #871 from private-attribution/boolean_array_dot_pr…

…oduct

Migrating the feature label dot product to use BooleanArray

ipa-core/src/ff/galois_field.rs

@@ -7,6 +7,7 @@ use bitvec::prelude::{bitarr, BitArr, Lsb0};
 use generic_array::GenericArray;
 use typenum::{Unsigned, U1, U2, U3, U4, U5};
 
+use super::ArrayAccess;
 use crate::{
     ff::{Field, Serializable},
     secret_sharing::{Block, SharedValue},
@@ -165,6 +166,23 @@ macro_rules! bit_array_impl {
                 }
             }
 
+            impl ArrayAccess for $name {
+                type Output = bool;
+
+                fn get(&self, index: usize) -> Option<Self::Output> {
+                    if index < usize::try_from(<$name>::BITS).unwrap() {
+                        Some(self.0[index].into())
+                    } else {
+                        None
+                    }
+                }
+
+                fn set(&mut self, index: usize, e: Self::Output) {
+                    debug_assert!(index < usize::try_from(<$name>::BITS).unwrap());
+                    self.0.set(index, bool::from(e));
+                }
+            }
+
             impl GaloisField for $name {
                 const POLYNOMIAL: u128 = $polynomial;
             }
@@ -613,16 +631,6 @@ bit_array_impl!(
     0b10_0001_1011_u128,
 );
 
-bit_array_impl!(
-    bit_array_5,
-    Gf5Bit,
-    U8_1,
-    5,
-    bitarr!(const u8, Lsb0; 1, 0, 0, 0, 0),
-    // x^5 + x^4 + x^3 + x^2 + x + 1
-    0b111_111_u128,
-);
-
 bit_array_impl!(
     bit_array_3,
     Gf3Bit,

ipa-core/src/ff/mod.rs

@@ -13,9 +13,7 @@ mod prime_field;
 use std::ops::{Add, AddAssign, Sub, SubAssign};
 
 pub use field::{Field, FieldType};
-pub use galois_field::{
-    GaloisField, Gf2, Gf20Bit, Gf32Bit, Gf3Bit, Gf40Bit, Gf5Bit, Gf8Bit, Gf9Bit,
-};
+pub use galois_field::{GaloisField, Gf2, Gf20Bit, Gf32Bit, Gf3Bit, Gf40Bit, Gf8Bit, Gf9Bit};
 use generic_array::{ArrayLength, GenericArray};
 #[cfg(any(test, feature = "weak-field"))]
 pub use prime_field::Fp31;

ipa-core/src/protocol/ipa/mod.rs

@@ -11,7 +11,7 @@ use typenum::Unsigned;
 
 use crate::{
     error::Error,
-    ff::{Field, GaloisField, Gf2, PrimeField, Serializable},
+    ff::{ArrayAccess, Field, Gf2, PrimeField, Serializable},
     helpers::{query::IpaQueryConfig, Role},
     protocol::{
         attribution::secure_attribution,
@@ -35,7 +35,7 @@ use crate::{
             semi_honest::AdditiveShare as Replicated,
             ReplicatedSecretSharing,
         },
-        BitDecomposed, Linear as LinearSecretSharing, LinearRefOps,
+        BitDecomposed, Linear as LinearSecretSharing, LinearRefOps, SharedValue,
     },
 };
 
@@ -60,15 +60,15 @@ pub(crate) enum IPAInputRowResharableStep {
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(Clone, PartialEq, Eq))]
-pub struct IPAInputRow<F: Field, MK: GaloisField, BK: GaloisField> {
+pub struct IPAInputRow<F: Field, MK: SharedValue, BK: SharedValue> {
     pub timestamp: Replicated<F>,
     pub mk_shares: Replicated<MK>,
     pub is_trigger_bit: Replicated<F>,
     pub breakdown_key: Replicated<BK>,
     pub trigger_value: Replicated<F>,
 }
 
-impl<F: Field, MK: GaloisField, BK: GaloisField> Serializable for IPAInputRow<F, MK, BK>
+impl<F: Field, MK: SharedValue, BK: SharedValue> Serializable for IPAInputRow<F, MK, BK>
 where
     Replicated<BK>: Serializable,
     Replicated<MK>: Serializable,
@@ -163,7 +163,7 @@ where
     }
 }
 
-impl<F: Field, MK: GaloisField, BK: GaloisField> IPAInputRow<F, MK, BK>
+impl<F: Field, MK: SharedValue, BK: SharedValue> IPAInputRow<F, MK, BK>
 where
     IPAInputRow<F, MK, BK>: Serializable,
 {
@@ -323,8 +323,8 @@ where
         + 'static,
     for<'r> &'r SB: LinearRefOps<'r, SB, Gf2>,
     F: PrimeField + ExtendableField,
-    MK: GaloisField,
-    BK: GaloisField,
+    MK: SharedValue + ArrayAccess<Output = bool>,
+    BK: SharedValue + ArrayAccess<Output = bool>,
     ShuffledPermutationWrapper<S, C::UpgradedContext<F>>: DowngradeMalicious<Target = Vec<u32>>,
     for<'u> UpgradeContext<'u, C::UpgradedContext<F>, F, RecordId>: UpgradeToMalicious<'u, BitConversionTriple<Replicated<F>>, BitConversionTriple<S>>
         + UpgradeToMalicious<
@@ -413,16 +413,16 @@ fn get_gf2_match_key_bits<F, MK, BK>(
 ) -> Vec<BitDecomposed<Replicated<Gf2>>>
 where
     F: PrimeField,
-    MK: GaloisField,
-    BK: GaloisField,
+    MK: SharedValue + ArrayAccess<Output = bool>,
+    BK: SharedValue + ArrayAccess<Output = bool>,
 {
     input_rows
         .iter()
         .map(|row| {
             BitDecomposed::decompose(MK::BITS, |i| {
                 Replicated::new(
-                    Gf2::truncate_from(row.mk_shares.left()[i]),
-                    Gf2::truncate_from(row.mk_shares.right()[i]),
+                    Gf2::truncate_from(row.mk_shares.left().get(i.try_into().unwrap()).unwrap()),
+                    Gf2::truncate_from(row.mk_shares.right().get(i.try_into().unwrap()).unwrap()),
                 )
             })
         })
@@ -434,16 +434,23 @@ fn get_gf2_breakdown_key_bits<F, MK, BK>(
 ) -> Vec<BitDecomposed<Replicated<Gf2>>>
 where
     F: PrimeField,
-    MK: GaloisField,
-    BK: GaloisField,
+    MK: SharedValue + ArrayAccess<Output = bool>,
+    BK: SharedValue + ArrayAccess<Output = bool>,
 {
     input_rows
         .iter()
         .map(|row| {
             BitDecomposed::decompose(BK::BITS, |i| {
                 Replicated::new(
-                    Gf2::truncate_from(row.breakdown_key.left()[i]),
-                    Gf2::truncate_from(row.breakdown_key.right()[i]),
+                    Gf2::truncate_from(
+                        row.breakdown_key.left().get(i.try_into().unwrap()).unwrap(),
+                    ),
+                    Gf2::truncate_from(
+                        row.breakdown_key
+                            .right()
+                            .get(i.try_into().unwrap())
+                            .unwrap(),
+                    ),
                 )
             })
         })