Papers
Topics
Authors
Recent
Search
2000 character limit reached

Blowfish Privacy: Tuning Privacy-Utility Trade-offs using Policies

Published 13 Dec 2013 in cs.DB | (1312.3913v5)

Abstract: Privacy definitions provide ways for trading-off the privacy of individuals in a statistical database for the utility of downstream analysis of the data. In this paper, we present Blowfish, a class of privacy definitions inspired by the Pufferfish framework, that provides a rich interface for this trade-off. In particular, we allow data publishers to extend differential privacy using a policy, which specifies (a) secrets, or information that must be kept secret, and (b) constraints that may be known about the data. While the secret specification allows increased utility by lessening protection for certain individual properties, the constraint specification provides added protection against an adversary who knows correlations in the data (arising from constraints). We formalize policies and present novel algorithms that can handle general specifications of sensitive information and certain count constraints. We show that there are reasonable policies under which our privacy mechanisms for k-means clustering, histograms and range queries introduce significantly lesser noise than their differentially private counterparts. We quantify the privacy-utility trade-offs for various policies analytically and empirically on real datasets.

Citations (189)

Summary

  • The paper presents a novel Blowfish privacy framework that augments differential privacy through policy-driven controls defining secrets and constraints.
  • It demonstrates reduced noise interference in tasks like k-means clustering, cumulative histograms, and range queries by leveraging policy-specific sensitivity metrics.
  • The framework promises enhanced data utility and accuracy in real-world applications, including spatial and social network data analysis.

Blowfish Privacy: Tuning Privacy-Utility Trade-offs using Policies

In the discourse of data privacy within statistical databases, the necessity of balancing privacy risks with data utility becomes crucial. The traditional mechanism of differential privacy, while robust, often provides an overly stringent measure of privacy that may result in utility degradation. This paper presents a novel approach, termed Blowfish privacy, that augments differential privacy through policy-driven controls which delineate the trade-offs between privacy protection and data utility.

The research introduces Blowfish privacy as a broader framework inspired by the Pufferfish privacy model. This framework provides more granular control by utilizing policies that specify particular "secrets"—individual pieces of information that require protection—and "constraints," which are assumed known traits or patterns within the data. The introduction of these policies allows data stakeholders to specify which data attributes should remain confidential and under what known constraints the data are correlated, offering a more customizable privacy-utility balance.

Strong numerical results are achieved by demonstrating that under realistic policy scenarios, data utilities such as k-means clustering, cumulative histograms, and range queries exhibit significantly reduced noise interference compared to traditional differentially private algorithms. Notably, the framework articulates new algorithms that work with reduced global sensitivity metrics for specific policies, including concepts of sparse auxiliary knowledge. For instance, policy-specific global sensitivity is carefully calculated within sparse constraints using policy graphs, which substantially enhance the performance of many common data analysis tasks.

The implications of this research are multifaceted. Practically, the Blowfish privacy framework allows for data analysis tasks to be performed with higher accuracy and effectiveness, especially in domains like spatial data analytics and social network datasets with inherent correlations. Theoretically, it proposes a novel structuring of data privacy norms that balance traditional aspects of differential privacy with nuanced trade-offs that cater to specific information and privacy requirements.

Future AI developments could see Blowfish privacy being extensively applied to machine learning and data-driven environments, primarily through enhanced policy specification models that further refine privacy protection without compromising utility. Moreover, the scalability of such models within complex data infrastructures remains an intriguing point of exploration, suggesting extensions of this research could include the refinement of policy-driven mechanisms in large-scale distributed data systems.

In summary, the Blowfish privacy framework represents a significant step forward in privacy-preserving data analysis, emphasizing the strategic balance of privacy protection and data utility through innovative use of policy-driven controls. The exploration of constraints and their integration into privacy measures serves as a fertile ground for further investigation, potentially leading to more robust and versatile privacy solutions in data-intensive applications.

Paper to Video (Beta)

Whiteboard

No one has generated a whiteboard explanation for this paper yet.

Open Problems

We haven't generated a list of open problems mentioned in this paper yet.

Collections

Sign up for free to add this paper to one or more collections.