77 research outputs found
Secure Two-Party Computation is Practical
Secure multi-party computation has been considered by the cryptographic community for a number of years. Until recently it has been a purely theoretical area, with few implementations with which to test various ideas. This has led to a number of optimisations being proposed which are quite restricted in their application. In this paper we describe an implementation of the two-party case, using Yao’s garbled circuits, and present various algorithmic protocol improvements. These optimisations are analysed both theoretically and empirically, using experiments of various adversarial situations. Our experimental data is provided for reasonably large circuits, including one which performs an AES encryption, a problem which we discuss in the context of various possible applications
Privacy-Preserving Genetic Relatedness Test
An increasing number of individuals are turning to Direct-To-Consumer (DTC)
genetic testing to learn about their predisposition to diseases, traits, and/or
ancestry. DTC companies like 23andme and Ancestry.com have started to offer
popular and affordable ancestry and genealogy tests, with services allowing
users to find unknown relatives and long-distant cousins. Naturally, access and
possible dissemination of genetic data prompts serious privacy concerns, thus
motivating the need to design efficient primitives supporting private genetic
tests. In this paper, we present an effective protocol for privacy-preserving
genetic relatedness test (PPGRT), enabling a cloud server to run relatedness
tests on input an encrypted genetic database and a test facility's encrypted
genetic sample. We reduce the test to a data matching problem and perform it,
privately, using searchable encryption. Finally, a performance evaluation of
hamming distance based PP-GRT attests to the practicality of our proposals.Comment: A preliminary version of this paper appears in the Proceedings of the
3rd International Workshop on Genome Privacy and Security (GenoPri'16
ARM2GC: Succinct Garbled Processor for Secure Computation
We present ARM2GC, a novel secure computation framework based on Yao's
Garbled Circuit (GC) protocol and the ARM processor. It allows users to develop
privacy-preserving applications using standard high-level programming languages
(e.g., C) and compile them using off-the-shelf ARM compilers (e.g., gcc-arm).
The main enabler of this framework is the introduction of SkipGate, an
algorithm that dynamically omits the communication and encryption cost of the
gates whose outputs are independent of the private data. SkipGate greatly
enhances the performance of ARM2GC by omitting costs of the gates associated
with the instructions of the compiled binary, which is known by both parties
involved in the computation. Our evaluation on benchmark functions demonstrates
that ARM2GC not only outperforms the current GC frameworks that support
high-level languages, it also achieves efficiency comparable to the best prior
solutions based on hardware description languages. Moreover, in contrast to
previous high-level frameworks with domain-specific languages and customized
compilers, ARM2GC relies on standard ARM compiler which is rigorously verified
and supports programs written in the standard syntax.Comment: 13 page
Anonymous subject identification and privacy information management in video surveillance
The widespread deployment of surveillance cameras has raised serious privacy concerns, and many privacy-enhancing schemes have been recently proposed to automatically redact images of selected individuals in the surveillance video for protection. Of equal importance are the privacy and efficiency of techniques to first, identify those individuals for privacy protection and second, provide access to original surveillance video contents for security analysis. In this paper, we propose an anonymous subject identification and privacy data management system to be used in privacy-aware video surveillance. The anonymous subject identification system uses iris patterns to identify individuals for privacy protection. Anonymity of the iris-matching process is guaranteed through the use of a garbled-circuit (GC)-based iris matching protocol. A novel GC complexity reduction scheme is proposed by simplifying the iris masking process in the protocol. A user-centric privacy information management system is also proposed that allows subjects to anonymously access their privacy information via their iris patterns. The system is composed of two encrypted-domain protocols: The privacy information encryption protocol encrypts the original video records using the iris pattern acquired during the subject identification phase; the privacy information retrieval protocol allows the video records to be anonymously retrieved through a GC-based iris pattern matching process. Experimental results on a public iris biometric database demonstrate the validity of our framework
Privacy-Aware Processing of Biometric Templates by Means of Secure Two-Party Computation
The use of biometric data for person identification and access control is gaining more and more popularity. Handling biometric data, however, requires particular care, since biometric data is indissolubly tied to the identity of the owner hence raising important security and privacy issues. This chapter focuses on the latter, presenting an innovative approach that, by relying on tools borrowed from Secure Two Party Computation (STPC) theory, permits to process the biometric data in encrypted form, thus eliminating any risk that private biometric information is leaked during an identification process. The basic concepts behind STPC are reviewed together with the basic cryptographic primitives needed to achieve privacy-aware processing of biometric data in a STPC context. The two main approaches proposed so far, namely homomorphic encryption and garbled circuits, are discussed and the way such techniques can be used to develop a full biometric matching protocol described. Some general guidelines to be used in the design of a privacy-aware biometric system are given, so as to allow the reader to choose the most appropriate tools depending on the application at hand
Reuse It Or Lose It: More Efficient Secure Computation Through Reuse of Encrypted Values
Two-party secure function evaluation (SFE) has become significantly more
feasible, even on resource-constrained devices, because of advances in
server-aided computation systems. However, there are still bottlenecks,
particularly in the input validation stage of a computation. Moreover, SFE
research has not yet devoted sufficient attention to the important problem of
retaining state after a computation has been performed so that expensive
processing does not have to be repeated if a similar computation is done again.
This paper presents PartialGC, an SFE system that allows the reuse of encrypted
values generated during a garbled-circuit computation. We show that using
PartialGC can reduce computation time by as much as 96% and bandwidth by as
much as 98% in comparison with previous outsourcing schemes for secure
computation. We demonstrate the feasibility of our approach with two sets of
experiments, one in which the garbled circuit is evaluated on a mobile device
and one in which it is evaluated on a server. We also use PartialGC to build a
privacy-preserving "friend finder" application for Android. The reuse of
previous inputs to allow stateful evaluation represents a new way of looking at
SFE and further reduces computational barriers.Comment: 20 pages, shorter conference version published in Proceedings of the
2014 ACM SIGSAC Conference on Computer and Communications Security, Pages
582-596, ACM New York, NY, US
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