[Identifiability Study] Add noise to Reid estimation
In this CL we add code for adding noise to the Reid score estimation with a probability controlled by a feature parameter. This CL is a continuation of the POC to estimate the REID score of sets of surfaces defined by the feature parameter kIdentifiabilityStudyReidSurfaceBlocks.
We add one feature setting that can be set from server-side:
kIdentifiabilityStudyReidSurfaceBlocksNoise. This parameter sets the probability of noise to be reported when computing the REID hash for the relative block of surfaces defined in kIdentifiabilityStudyReidSurfaceBlocks parameter.
Bug: 1330244
Change-Id: I0a7de4379a959a3be503cf2d01ef68ba283d9f40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3771820
Commit-Queue: Saeid Eid <saeideid@chromium.org>
Reviewed-by: Antonio Sartori <antoniosartori@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1026185}
diff --git a/chrome/browser/privacy_budget/identifiability_study_group_settings.cc b/chrome/browser/privacy_budget/identifiability_study_group_settings.cc
index 035515c1..c6af150 100644
--- a/chrome/browser/privacy_budget/identifiability_study_group_settings.cc
+++ b/chrome/browser/privacy_budget/identifiability_study_group_settings.cc
@@ -34,7 +34,8 @@
features::kIdentifiabilityStudyAllowedRandomTypes.Get(),
features::kIdentifiabilityStudyReidSurfaceBlocks.Get(),
features::kIdentifiabilityStudyReidSurfaceBlocksSaltsRanges.Get(),
- features::kIdentifiabilityStudyReidSurfaceBlocksBits.Get());
+ features::kIdentifiabilityStudyReidSurfaceBlocksBits.Get(),
+ features::kIdentifiabilityStudyReidBlocksNoiseProbabilities.Get());
}
// static
@@ -47,7 +48,8 @@
const std::string& allowed_random_types,
const std::string& reid_blocks,
const std::string& reid_blocks_salts_ranges,
- const std::string& reid_blocks_bits) {
+ const std::string& reid_blocks_bits,
+ const std::string& reid_blocks_noise_probabilities) {
return IdentifiabilityStudyGroupSettings(
enabled, expected_surface_count, surface_budget,
DecodeIdentifiabilityFieldTrialParam<IdentifiableSurfaceBlocks>(blocks),
@@ -58,7 +60,9 @@
reid_blocks),
DecodeIdentifiabilityFieldTrialParam<std::vector<uint64_t>>(
reid_blocks_salts_ranges),
- DecodeIdentifiabilityFieldTrialParam<std::vector<int>>(reid_blocks_bits));
+ DecodeIdentifiabilityFieldTrialParam<std::vector<int>>(reid_blocks_bits),
+ DecodeIdentifiabilityFieldTrialParam<std::vector<double>>(
+ reid_blocks_noise_probabilities));
}
IdentifiabilityStudyGroupSettings::IdentifiabilityStudyGroupSettings(
@@ -70,7 +74,8 @@
std::vector<blink::IdentifiableSurface::Type> allowed_random_types,
IdentifiableSurfaceBlocks reid_blocks,
std::vector<uint64_t> reid_blocks_salts_ranges,
- std::vector<int> reid_blocks_bits)
+ std::vector<int> reid_blocks_bits,
+ std::vector<double> reid_blocks_noise_probabilities)
: enabled_(enabled),
expected_surface_count_(base::clamp<int>(
expected_surface_count,
@@ -85,6 +90,8 @@
reid_blocks_(std::move(reid_blocks)),
reid_blocks_salts_ranges_(std::move(reid_blocks_salts_ranges)),
reid_blocks_bits_(std::move(reid_blocks_bits)),
+ reid_blocks_noise_probabilities_(
+ std::move(reid_blocks_noise_probabilities)),
allowed_random_types_(std::move(allowed_random_types)) {
bool validates = Validate();
UmaHistogramFinchConfigValidation(validates);
@@ -155,15 +162,22 @@
bool IdentifiabilityStudyGroupSettings::ValidateReidBlockEstimator() {
if (reid_blocks_salts_ranges_.size() != reid_blocks_.size() ||
- reid_blocks_bits_.size() != reid_blocks_.size())
+ reid_blocks_bits_.size() != reid_blocks_.size() ||
+ reid_blocks_noise_probabilities_.size() != reid_blocks_.size())
return false;
- bool valid_ranges =
+ bool valid_params =
base::ranges::all_of(reid_blocks_salts_ranges_,
[](uint64_t salt_range) { return salt_range > 0; });
- return valid_ranges &&
- base::ranges::all_of(reid_blocks_bits_, [](int reid_bits) {
- return reid_bits > 0 && reid_bits <= 32;
- });
+ valid_params = valid_params &&
+ base::ranges::all_of(reid_blocks_bits_, [](int reid_bits) {
+ return reid_bits > 0 && reid_bits <= 32;
+ });
+
+ return valid_params && base::ranges::all_of(reid_blocks_noise_probabilities_,
+ [](double reid_noise) {
+ return reid_noise >= 0 &&
+ reid_noise <= 1;
+ });
}
const IdentifiableSurfaceBlocks& IdentifiabilityStudyGroupSettings::blocks()
@@ -186,6 +200,11 @@
return reid_blocks_bits_;
}
+const std::vector<double>&
+IdentifiabilityStudyGroupSettings::reid_blocks_noise_probabilities() const {
+ return reid_blocks_noise_probabilities_;
+}
+
const IdentifiableSurfaceBlocks&
IdentifiabilityStudyGroupSettings::reid_blocks() const {
return reid_blocks_;
diff --git a/chrome/browser/privacy_budget/identifiability_study_group_settings.h b/chrome/browser/privacy_budget/identifiability_study_group_settings.h
index 8556493..0c32a9c 100644
--- a/chrome/browser/privacy_budget/identifiability_study_group_settings.h
+++ b/chrome/browser/privacy_budget/identifiability_study_group_settings.h
@@ -28,7 +28,8 @@
const std::string& allowed_random_types,
const std::string& reid_blocks,
const std::string& reid_blocks_salts_ranges,
- const std::string& reid_blocks_bits);
+ const std::string& reid_blocks_bits,
+ const std::string& reid_blocks_noise_probabilities);
IdentifiabilityStudyGroupSettings(const IdentifiabilityStudyGroupSettings&) =
delete;
@@ -56,6 +57,7 @@
const std::vector<double>& blocks_weights() const;
const std::vector<uint64_t>& reid_blocks_salts_ranges() const;
const std::vector<int>& reid_blocks_bits() const;
+ const std::vector<double>& reid_blocks_noise_probabilities() const;
const std::vector<blink::IdentifiableSurface::Type>& allowed_random_types()
const;
@@ -72,7 +74,8 @@
std::vector<blink::IdentifiableSurface::Type> allowed_random_types,
IdentifiableSurfaceBlocks reid_blocks,
std::vector<uint64_t> reid_blocks_salts_ranges,
- std::vector<int> reid_blocks_bits);
+ std::vector<int> reid_blocks_bits,
+ std::vector<double> reid_blocks_noise_probabilities);
bool Validate();
bool ValidateAssignedBlockSampling();
@@ -96,6 +99,8 @@
const std::vector<int> reid_blocks_bits_;
+ const std::vector<double> reid_blocks_noise_probabilities_;
+
// Surface types to sample from when random surface sampling is enabled. If
// this vector is empty all surface types are allowed to be sampled.
const std::vector<blink::IdentifiableSurface::Type> allowed_random_types_;
diff --git a/chrome/browser/privacy_budget/identifiability_study_group_settings_unittest.cc b/chrome/browser/privacy_budget/identifiability_study_group_settings_unittest.cc
index bcdc2bb7..e435840 100644
--- a/chrome/browser/privacy_budget/identifiability_study_group_settings_unittest.cc
+++ b/chrome/browser/privacy_budget/identifiability_study_group_settings_unittest.cc
@@ -14,7 +14,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, Disabled) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- false, 0, 0, "", "", "", "", "", "");
+ false, 0, 0, "", "", "", "", "", "", "");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", true, 1);
@@ -22,7 +22,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, DisabledWithParams) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- false, 10, 40, "", "", "", "", "", "");
+ false, 10, 40, "", "", "", "", "", "", "");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", true, 1);
@@ -30,7 +30,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, DisabledBySurfaceCountZero) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 40, "", "", "", "", "", "");
+ true, 0, 40, "", "", "", "", "", "", "");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", false, 1);
@@ -38,7 +38,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, ValidRandomSurfaceSampling) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 10, 40, "", "", "1,4", "", "", "");
+ true, 10, 40, "", "", "1,4", "", "", "", "");
EXPECT_TRUE(settings.enabled());
EXPECT_FALSE(settings.IsUsingAssignedBlockSampling());
EXPECT_TRUE(settings.IsUsingRandomSampling());
@@ -56,7 +56,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, ValidAssignedBlockSampling) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "1;2,3;4,5;6", "1,1,1", "", "", "", "");
+ true, 0, 0, "1;2,3;4,5;6", "1,1,1", "", "", "", "", "");
EXPECT_TRUE(settings.enabled());
EXPECT_TRUE(settings.IsUsingAssignedBlockSampling());
EXPECT_FALSE(settings.IsUsingRandomSampling());
@@ -67,7 +67,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, InvalidNegativeWeight) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "1;2,3;4,5;6", "-1,1,1", "", "", "", "");
+ true, 0, 0, "1;2,3;4,5;6", "-1,1,1", "", "", "", "", "");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", false, 1);
@@ -75,7 +75,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, InvalidSurfaceTooLikely) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "1;2,1;4,5;6", "1,1,1", "", "", "", "");
+ true, 0, 0, "1;2,1;4,5;6", "1,1,1", "", "", "", "", "");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", false, 1);
@@ -83,7 +83,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, EnableSettingsForValidReidBlock) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "", "", "", "1;2,4;5;6", "2,2", "2,3");
+ true, 0, 0, "", "", "", "1;2,4;5;6", "2,2", "2,3", "0.1,0.2");
EXPECT_TRUE(settings.IsUsingReidScoreEstimator());
EXPECT_FALSE(settings.IsUsingSamplingOfSurfaces());
EXPECT_TRUE(settings.enabled());
@@ -93,7 +93,7 @@
TEST_F(IdentifiabilityStudyGroupSettingsTest, InvalidReidBlocks) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "", "", "", "1;2,4;5;6", "2", "2,3");
+ true, 0, 0, "", "", "", "1;2,4;5;6", "2", "2,3", "0.1,0.2");
EXPECT_FALSE(settings.enabled());
histogram_tester.ExpectUniqueSample(
"PrivacyBudget.Identifiability.FinchConfigValidationResult", false, 1);
diff --git a/chrome/browser/privacy_budget/privacy_budget_reid_score_browsertest.cc b/chrome/browser/privacy_budget/privacy_budget_reid_score_browsertest.cc
index 3100734e..e29720ab 100644
--- a/chrome/browser/privacy_budget/privacy_budget_reid_score_browsertest.cc
+++ b/chrome/browser/privacy_budget/privacy_budget_reid_score_browsertest.cc
@@ -42,6 +42,7 @@
parameters.reid_salts_ranges = {1};
parameters.reid_bits = {1};
+ parameters.reid_noise = {0.01};
scoped_config_.Apply(parameters);
}
diff --git a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.cc b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.cc
index 46fd54d..bd27dfb 100644
--- a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.cc
+++ b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.cc
@@ -40,6 +40,8 @@
IdentifiableSurfaceBlocks reid_blocks = state_settings.reid_blocks();
reid_blocks_salts_ranges_ = state_settings.reid_blocks_salts_ranges();
reid_blocks_bits_ = state_settings.reid_blocks_bits();
+ reid_blocks_noise_probabilities_ =
+ state_settings.reid_blocks_noise_probabilities();
// Step 2: Get the type of the Reid surface.
constexpr auto kReidScoreType =
@@ -93,7 +95,7 @@
// Compute the Reid hash for the needed Reid block.
uint64_t reid_hash = ComputeHashForReidScore(
*surface_map, reid_blocks_salts_ranges_.at(i),
- reid_blocks_bits_.at(i));
+ reid_blocks_bits_.at(i), reid_blocks_noise_probabilities_.at(i));
// Report to UKM in a separate task in order to avoid re-entrancy.
base::SequencedTaskRunnerHandle::Get()->PostTask(
FROM_HERE, base::BindOnce(&ReportHashForReidScore, map_itr.first,
@@ -108,7 +110,8 @@
uint64_t PrivacyBudgetReidScoreEstimator::ComputeHashForReidScore(
const SurfacesAndOptionalValues& surface_map,
uint64_t max_num_salt,
- int reid_bits) {
+ int reid_bits,
+ double reid_noise_probability) {
std::vector<uint64_t> tokens;
uint64_t salt = base::RandGenerator(max_num_salt);
@@ -117,11 +120,18 @@
tokens.emplace_back(
static_cast<uint64_t>(surface_itr.second->ToUkmMetricValue()));
}
- // Use the hash function embedded in IdentifiableToken.
- uint64_t reid_hash = blink::IdentifiabilityDigestOfBytes(
- base::as_bytes(base::make_span(tokens)));
+ // Initialize Reid hash with random noise.
+ uint64_t reid_hash = base::RandUint64();
+ // Calculate the real hash if the random number is greater than the Reid noise
+ // probability.
+ if (base::RandDouble() >= reid_noise_probability) {
+ // Use the hash function embedded in IdentifiableToken.
+ reid_hash = blink::IdentifiabilityDigestOfBytes(
+ base::as_bytes(base::make_span(tokens)));
+ }
// Create mask based on reid_bits required.
- uint64_t mask = (1 << reid_bits) - 1;
+ constexpr uint64_t kTypedOne = 1;
+ uint64_t mask = (kTypedOne << reid_bits) - 1;
uint64_t needed_bits = reid_hash & mask;
// Return salt in the left 32 bits and Reid b-bits hash in the right 32 bits.
return ((salt << 32) | needed_bits);
diff --git a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.h b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.h
index b251286..d8365df 100644
--- a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.h
+++ b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator.h
@@ -43,6 +43,10 @@
// surface block.
std::vector<int> reid_blocks_bits_;
+ // Keeps track of the probability of noise that should be reported for every
+ // Reid surface block.
+ std::vector<double> reid_blocks_noise_probabilities_;
+
// Keeps track of the number of reported surfaces in every Reid surface block.
// The Reid surface map at index i is full when the count_flag_ at i is equal
// to the number of surfaces in that map i.e. size of the map.
@@ -51,7 +55,8 @@
// Compute the hash for estimating the REID score.
uint64_t ComputeHashForReidScore(const SurfacesAndOptionalValues& surface_map,
uint64_t max_num_salt,
- int reid_bits);
+ int reid_bits,
+ double reid_noise_probability);
};
#endif // CHROME_BROWSER_PRIVACY_BUDGET_PRIVACY_BUDGET_UKM_ENTRY_FILTER_H_
diff --git a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator_unittest.cc b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator_unittest.cc
index 611c6c0..d1881a0 100644
--- a/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator_unittest.cc
+++ b/chrome/browser/privacy_budget/privacy_budget_reid_score_estimator_unittest.cc
@@ -5,6 +5,7 @@
#include <cstdint>
#include "base/barrier_closure.h"
+#include "base/containers/flat_set.h"
#include "base/rand_util.h"
#include "base/test/task_environment.h"
#include "chrome/browser/privacy_budget/identifiability_study_group_settings.h"
@@ -17,7 +18,7 @@
TEST(PrivacyBudgetReidScoreEstimatorStandaloneTest,
ReportReidFixedTokenRandomSalt) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "", "", "", "2077075229;1122849309", "1000000", "1");
+ true, 0, 0, "", "", "", "2077075229;1122849309", "1000000", "1", "0");
constexpr auto surface_1 =
blink::IdentifiableSurface::FromMetricHash(2077075229u);
@@ -78,7 +79,7 @@
TEST(PrivacyBudgetReidScoreEstimatorStandaloneTest,
ReportReidRandomTokenFixedSalt) {
auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
- true, 0, 0, "", "", "", "2077075229;1122849309", "1", "1");
+ true, 0, 0, "", "", "", "2077075229;1122849309", "1", "1", "0");
constexpr auto surface_1 =
blink::IdentifiableSurface::FromMetricHash(2077075229u);
constexpr auto surface_2 =
@@ -134,3 +135,57 @@
EXPECT_TRUE(has_value_0);
EXPECT_TRUE(has_value_1);
}
+
+TEST(PrivacyBudgetReidScoreEstimatorStandaloneTest,
+ ReportReidFixedTokenFixedSaltAllNoise) {
+ auto settings = IdentifiabilityStudyGroupSettings::InitFrom(
+ true, 0, 0, "", "", "", "2077075229;1122849309", "1", "32", "1");
+
+ constexpr auto surface_1 =
+ blink::IdentifiableSurface::FromMetricHash(2077075229u);
+ constexpr auto surface_2 =
+ blink::IdentifiableSurface::FromMetricHash(1122849309u);
+
+ int64_t token1 = 1234;
+ int64_t token2 = 12345;
+ constexpr int num_iterations = 50;
+ base::test::SingleThreadTaskEnvironment task_environment;
+ ukm::TestAutoSetUkmRecorder test_recorder;
+ base::RunLoop run_loop;
+ test_recorder.SetOnAddEntryCallback(
+ ukm::builders::Identifiability::kEntryName,
+ base::BarrierClosure(num_iterations, run_loop.QuitClosure()));
+ blink::test::ScopedIdentifiabilityTestSampleCollector collector;
+ for (int i = 0; i < num_iterations; ++i) {
+ auto reid_storage =
+ std::make_unique<PrivacyBudgetReidScoreEstimator>(settings);
+ // Process values for 2 surfaces.
+ reid_storage->ProcessForReidScore(surface_1,
+ blink::IdentifiableToken(token1));
+ reid_storage->ProcessForReidScore(surface_2,
+ blink::IdentifiableToken(token2));
+ }
+ // This should let the async tasks run.
+ run_loop.Run();
+ const auto& entries = collector.entries();
+ base::flat_set<uint32_t> reid_results;
+ int count = 0;
+ for (auto& entry : entries) {
+ for (auto& metric : entry.metrics) {
+ auto surface = metric.surface;
+ if (surface.GetType() ==
+ blink::IdentifiableSurface::Type::kReidScoreEstimator) {
+ EXPECT_EQ(metric.surface.ToUkmMetricHash(), 7415899889871487013u);
+ ++count;
+ uint64_t hash = static_cast<uint64_t>(metric.value.ToUkmMetricValue());
+ uint32_t reid_bits = hash & 0xFFFFFFFF;
+ // Result should be noise i.e. didn't appeared before.
+ EXPECT_FALSE(reid_results.contains(reid_bits));
+ reid_results.insert(reid_bits);
+ uint32_t salt = (hash >> 32);
+ EXPECT_EQ(salt, 0u);
+ }
+ }
+ }
+ EXPECT_EQ(count, num_iterations);
+}
diff --git a/chrome/common/privacy_budget/privacy_budget_features.cc b/chrome/common/privacy_budget/privacy_budget_features.cc
index fffd844e..8745ba8 100644
--- a/chrome/common/privacy_budget/privacy_budget_features.cc
+++ b/chrome/common/privacy_budget/privacy_budget_features.cc
@@ -62,5 +62,8 @@
const base::FeatureParam<std::string>
kIdentifiabilityStudyReidSurfaceBlocksBits = {&kIdentifiabilityStudy,
"ReidBlocksBits", ""};
+const base::FeatureParam<std::string>
+ kIdentifiabilityStudyReidBlocksNoiseProbabilities = {
+ &kIdentifiabilityStudy, "ReidBlocksNoiseProbabilities", ""};
} // namespace features
diff --git a/chrome/common/privacy_budget/privacy_budget_features.h b/chrome/common/privacy_budget/privacy_budget_features.h
index 627c0db..472a26a 100644
--- a/chrome/common/privacy_budget/privacy_budget_features.h
+++ b/chrome/common/privacy_budget/privacy_budget_features.h
@@ -400,6 +400,27 @@
extern const base::FeatureParam<std::string>
kIdentifiabilityStudyReidSurfaceBlocksBits;
+// Probabilities of reporting noise in Reid estimation.
+//
+// Parameter name: "ReidBlocksNoiseProbabilities"
+// Parameter type: Comma separated list of noise probabilities represented as
+// decimals.
+//
+// If this parameter is specified then it must specify the probability of noise
+// that should be reported for each block that is defined using the `ReidBlocks`
+// parameter. The probability should be a decimal between 0 and 1.
+//
+// * All probabilities must be positive decimals between 0 and 1.
+//
+// * There must be exactly as many Reid noise probabilities as there are Reid
+// blocks. If not, disable the Reid estimator feature.
+//
+// E.g.:
+// * "0.1,0.05": Assigns probabilities of noise that should be reported from
+// two Reid Blocks sent in the `ReidBlocks` parameter.
+extern const base::FeatureParam<std::string>
+ kIdentifiabilityStudyReidBlocksNoiseProbabilities;
+
} // namespace features
#endif // CHROME_COMMON_PRIVACY_BUDGET_PRIVACY_BUDGET_FEATURES_H_
diff --git a/chrome/common/privacy_budget/scoped_privacy_budget_config.cc b/chrome/common/privacy_budget/scoped_privacy_budget_config.cc
index b2375db..505895c6 100644
--- a/chrome/common/privacy_budget/scoped_privacy_budget_config.cc
+++ b/chrome/common/privacy_budget/scoped_privacy_budget_config.cc
@@ -130,6 +130,11 @@
ftp.insert({features::kIdentifiabilityStudyReidSurfaceBlocksBits.name,
EncodeIdentifiabilityFieldTrialParam(parameters.reid_bits)});
}
+ if (!parameters.reid_noise.empty()) {
+ ftp.insert(
+ {features::kIdentifiabilityStudyReidBlocksNoiseProbabilities.name,
+ EncodeIdentifiabilityFieldTrialParam(parameters.reid_noise)});
+ }
if (!parameters.per_surface_cost.empty()) {
ftp.insert(
{features::kIdentifiabilityStudyPerHashCost.name,
diff --git a/chrome/common/privacy_budget/scoped_privacy_budget_config.h b/chrome/common/privacy_budget/scoped_privacy_budget_config.h
index d4e32b61..befb6fac 100644
--- a/chrome/common/privacy_budget/scoped_privacy_budget_config.h
+++ b/chrome/common/privacy_budget/scoped_privacy_budget_config.h
@@ -67,6 +67,7 @@
IdentifiableSurfaceBlocks reid_blocks;
std::vector<uint64_t> reid_salts_ranges;
std::vector<int> reid_bits;
+ std::vector<double> reid_noise;
std::vector<blink::IdentifiableSurface::Type> allowed_random_types;
bool enable_active_sampling = false;
std::vector<std::string> actively_sampled_fonts;
diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
index 0a67e0b..2e72d5eb 100644
--- a/testing/variations/fieldtrial_testing_config.json
+++ b/testing/variations/fieldtrial_testing_config.json
@@ -5104,6 +5104,7 @@
"Gen": "8",
"ReidBlocks": "18009598079355128088,9223784233214641190;10735872651981970214",
"ReidBlocksBits": "1,4",
+ "ReidBlocksNoiseProbabilities": "0.01,0.01",
"ReidBlocksSaltsRanges": "1000,1000000"
},
"enable_features": [
