[Resource Topic] 2022/1536: Privacy-Preserving Blueprints

Welcome to the resource topic for 2022/1536

Title:
Privacy-Preserving Blueprints

Authors: Markulf Kohlweiss, Anna Lysyanskaya, An Nguyen

Abstract:

In a world where everyone uses anonymous credentials for all access control needs, it is impossible to trace wrongdoers, by design. This makes legitimate controls, such as tracing illicit trade and terror suspects, impossible to carry out. Here, we propose a privacy-preserving blueprint capability that allows an auditor to publish an encoding pk_A of the function f(x,\cdot) for a publicly known function f and a secret input x. For example, x may be a secret watchlist, and f(x,y) may return y if y\in x. On input her data y and the auditor’s pk_A, a user can compute an escrow Z such that anyone can verify that Z was computed correctly from the user’s credential attributes, and moreover, the auditor can recover f(x,y) from Z. Our contributions are:

  • We define secure f-blueprint systems; our definition is designed to provide a modular extension to anonymous credential systems.

  • We show that secure f-blueprint systems can be constructed for all functions f from fully homomorphic encryption and NIZK proof systems. This result is of theoretical interest but is not efficient enough for practical use.

  • We realize an optimal blueprint system under the DDH assumption in the random-oracle model for the watchlist function.

ePrint: https://eprint.iacr.org/2022/1536

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .