18,368 research outputs found
Extended Combinatorial Constructions for Peer-to-peer User-Private Information Retrieval
We consider user-private information retrieval (UPIR), an interesting
alternative to private information retrieval (PIR) introduced by Domingo-Ferrer
et al. In UPIR, the database knows which records have been retrieved, but does
not know the identity of the query issuer. The goal of UPIR is to disguise user
profiles from the database. Domingo-Ferrer et al.\ focus on using a
peer-to-peer community to construct a UPIR scheme, which we term P2P UPIR. In
this paper, we establish a strengthened model for P2P UPIR and clarify the
privacy goals of such schemes using standard terminology from the field of
privacy research. In particular, we argue that any solution providing privacy
against the database should attempt to minimize any corresponding loss of
privacy against other users. We give an analysis of existing schemes, including
a new attack by the database. Finally, we introduce and analyze two new
protocols. Whereas previous work focuses on a special type of combinatorial
design known as a configuration, our protocols make use of more general
designs. This allows for flexibility in protocol set-up, allowing for a choice
between having a dynamic scheme (in which users are permitted to enter and
leave the system), or providing increased privacy against other users.Comment: Updated version, which reflects reviewer comments and includes
expanded explanations throughout. Paper is accepted for publication by
Advances in Mathematics of Communication
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
Economics of intelligent selection of wireless access networks in a market-based framework : a game-theoretic approach
The Digital Marketplace is a market-based framework where network operators offer communications services with competition at the call level. It strives to address a tussle between the actors involved in a heterogeneous wireless access network. However, as with any market-like institution, it is vital to analyze the Digital Marketplace from the strategic perspective to ensure that all shortcomings are removed prior to implementation. In this paper, we analyze the selling mechanism proposed in the Digital Marketplace. The mechanism is based on a procurement first-price sealed-bid auction where the network operators represent the sellers/bidders, and the end-user of a wireless service is the buyer. However, this auction format is somewhat unusual as the winning bid is a composition of both the network operator’s monetary bid and their reputation rating. We create a simple economic model of the auction, and we show that it is mathematically intractable to derive the equilibrium bidding behavior when there are N network operators, and we make only generic assumptions about the structure of the bidding strategies. We then move on to consider a scenario with only two network operators, and assume that network operators use bidding strategies which are linear functions of their costs. This results in the derivation of the equilibrium bidding behavior in that scenario
Flexible and Robust Privacy-Preserving Implicit Authentication
Implicit authentication consists of a server authenticating a user based on
the user's usage profile, instead of/in addition to relying on something the
user explicitly knows (passwords, private keys, etc.). While implicit
authentication makes identity theft by third parties more difficult, it
requires the server to learn and store the user's usage profile. Recently, the
first privacy-preserving implicit authentication system was presented, in which
the server does not learn the user's profile. It uses an ad hoc two-party
computation protocol to compare the user's fresh sampled features against an
encrypted stored user's profile. The protocol requires storing the usage
profile and comparing against it using two different cryptosystems, one of them
order-preserving; furthermore, features must be numerical. We present here a
simpler protocol based on set intersection that has the advantages of: i)
requiring only one cryptosystem; ii) not leaking the relative order of fresh
feature samples; iii) being able to deal with any type of features (numerical
or non-numerical).
Keywords: Privacy-preserving implicit authentication, privacy-preserving set
intersection, implicit authentication, active authentication, transparent
authentication, risk mitigation, data brokers.Comment: IFIP SEC 2015-Intl. Information Security and Privacy Conference, May
26-28, 2015, IFIP AICT, Springer, to appea
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