Bloom Filter Cardinality Estimation for Privacy-Safe Audience Deduplication

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing audience measurement systems face challenges in accurately estimating unique audience size across multiple datasets while preserving user privacy, as they rely on third-party cookies which may be limited or unavailable, and deduplication techniques involving personally identifiable information (PII) are undesirable due to privacy concerns and computational inefficiencies.

Innovation Solution

The use of Bloom filter arrays to generate sketch data that summarizes media exposure across multiple datasets, allowing for the estimation of cardinality without revealing individual identities, thereby enabling accurate deduplication of audience members and preserving privacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deduplication techniques using personally identifiable information (PII) are employed to estimate unique audience size, then measurement precision is improved, but privacy protection deteriorates and device complexity increases

Engineering Contradiction:
Improveaudience size estimation accuracyVSAvoiduser privacy exposure
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the essential identifying features needed for deduplication while removing personally identifiable information. Bloom filters capture presence/absence patterns of users across datasets without storing actual PII, thereby achieving deduplication functionality while protecting user privacy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Bloom filters serve as an intermediary data structure between raw PII and final audience metrics. They transform detailed user information into a compact probabilistic representation that enables deduplication across datasets while preventing direct access to individual user identities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional deduplication methods using PII are used, then cardinality estimation accuracy is improved, but computational efficiency deteriorates and memory usage increases

Engineering Contradiction:
Improvecardinality estimation accuracyVSAvoidcomputational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent creates a compact copy of user presence information using Bloom filters instead of storing complete user profiles. This copied representation maintains sufficient information for deduplication while dramatically reducing memory requirements and computational overhead for processing large datasets.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the parameter representation from detailed PII fields to a compact bit array structure. By transforming user information into a fixed-size Bloom filter representation, the system achieves constant-time operations regardless of dataset size, improving computational efficiency while maintaining estimation accuracy.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If complete user data is shared across multiple database proprietors for audience measurement, then measurement precision is improved, but privacy protection deteriorates

Engineering Contradiction:
Improvecross-platform audience measurement accuracyVSAvoiduser privacy exposure
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the minimal necessary information for cross-platform deduplication - specifically, user presence patterns across datasets - while leaving out all personally identifiable information. This extracted representation enables accurate audience measurement across multiple database proprietors without exposing user privacy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Bloom filters act as a privacy-preserving intermediary that allows multiple database proprietors to collaboratively measure cross-platform audiences. Each proprietor can contribute to the aggregated measurement using their own Bloom filters without sharing raw user data, enabling precision while maintaining privacy boundaries.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS12602702B2Methods and apparatus to estimate cardinality across multiple datasets represented using bloom filter arrays
Publication Date: 2026.04.14 THE NIELSEN CO (US) LLC
  • US12602702B2 patent drawing
  • US12602702B2 patent drawing
  • US12602702B2 patent drawing

AI summary

Methods and apparatus to estimate cardinality across multiple datasets represented using Bloom filter arrays are disclosed. Disclosed examples include processor circuitry to execute and/or instantiate instructions to determine an inclusion-exclusion expression that defines an audience size for a user group of interest. Terms in the inclusion-exclusion expression corresponding to either a first cardinality of a first one of at least three Bloom filter arrays or a second cardinality of a union of two or more of the Bloom filter arrays. Different ones of the Bloom filter arrays representative of different sets of users who accessed media. The at least one processor further to estimate, based on the inclusion-exclusion expression, the audience size of the user group of interest.