2,915 research outputs found
Privacy-Preserving Trust Management Mechanisms from Private Matching Schemes
Cryptographic primitives are essential for constructing privacy-preserving
communication mechanisms. There are situations in which two parties that do not
know each other need to exchange sensitive information on the Internet. Trust
management mechanisms make use of digital credentials and certificates in order
to establish trust among these strangers. We address the problem of choosing
which credentials are exchanged. During this process, each party should learn
no information about the preferences of the other party other than strictly
required for trust establishment. We present a method to reach an agreement on
the credentials to be exchanged that preserves the privacy of the parties. Our
method is based on secure two-party computation protocols for set intersection.
Namely, it is constructed from private matching schemes.Comment: The material in this paper will be presented in part at the 8th DPM
International Workshop on Data Privacy Management (DPM 2013
The Crypto-democracy and the Trustworthy
In the current architecture of the Internet, there is a strong asymmetry in
terms of power between the entities that gather and process personal data
(e.g., major Internet companies, telecom operators, cloud providers, ...) and
the individuals from which this personal data is issued. In particular,
individuals have no choice but to blindly trust that these entities will
respect their privacy and protect their personal data. In this position paper,
we address this issue by proposing an utopian crypto-democracy model based on
existing scientific achievements from the field of cryptography. More
precisely, our main objective is to show that cryptographic primitives,
including in particular secure multiparty computation, offer a practical
solution to protect privacy while minimizing the trust assumptions. In the
crypto-democracy envisioned, individuals do not have to trust a single physical
entity with their personal data but rather their data is distributed among
several institutions. Together these institutions form a virtual entity called
the Trustworthy that is responsible for the storage of this data but which can
also compute on it (provided first that all the institutions agree on this).
Finally, we also propose a realistic proof-of-concept of the Trustworthy, in
which the roles of institutions are played by universities. This
proof-of-concept would have an important impact in demonstrating the
possibilities offered by the crypto-democracy paradigm.Comment: DPM 201
Zero-Knowledge Proof-of-Identity: Sybil-Resistant, Anonymous Authentication on Permissionless Blockchains and Incentive Compatible, Strictly Dominant Cryptocurrencies
Zero-Knowledge Proof-of-Identity from trusted public certificates (e.g.,
national identity cards and/or ePassports; eSIM) is introduced here to
permissionless blockchains in order to remove the inefficiencies of
Sybil-resistant mechanisms such as Proof-of-Work (i.e., high energy and
environmental costs) and Proof-of-Stake (i.e., capital hoarding and lower
transaction volume). The proposed solution effectively limits the number of
mining nodes a single individual would be able to run while keeping membership
open to everyone, circumventing the impossibility of full decentralization and
the blockchain scalability trilemma when instantiated on a blockchain with a
consensus protocol based on the cryptographic random selection of nodes.
Resistance to collusion is also considered.
Solving one of the most pressing problems in blockchains, a zk-PoI
cryptocurrency is proved to have the following advantageous properties:
- an incentive-compatible protocol for the issuing of cryptocurrency rewards
based on a unique Nash equilibrium
- strict domination of mining over all other PoW/PoS cryptocurrencies, thus
the zk-PoI cryptocurrency becoming the preferred choice by miners is proved to
be a Nash equilibrium and the Evolutionarily Stable Strategy
- PoW/PoS cryptocurrencies are condemned to pay the Price of Crypto-Anarchy,
redeemed by the optimal efficiency of zk-PoI as it implements the social
optimum
- the circulation of a zk-PoI cryptocurrency Pareto dominates other PoW/PoS
cryptocurrencies
- the network effects arising from the social networks inherent to national
identity cards and ePassports dominate PoW/PoS cryptocurrencies
- the lower costs of its infrastructure imply the existence of a unique
equilibrium where it dominates other forms of paymentComment: 2.1: Proof-of-Personhood Considered Harmful (and Illegal); 4.1.5:
Absence of Active Authentication; 4.2.6: Absence of Active Authentication;
4.2.7: Removing Single-Points of Failure; 4.3.2: Combining with
Non-Zero-Knowledge Authentication; 4.4: Circumventing the Impossibility of
Full Decentralizatio
Supporting Regularized Logistic Regression Privately and Efficiently
As one of the most popular statistical and machine learning models, logistic
regression with regularization has found wide adoption in biomedicine, social
sciences, information technology, and so on. These domains often involve data
of human subjects that are contingent upon strict privacy regulations.
Increasing concerns over data privacy make it more and more difficult to
coordinate and conduct large-scale collaborative studies, which typically rely
on cross-institution data sharing and joint analysis. Our work here focuses on
safeguarding regularized logistic regression, a widely-used machine learning
model in various disciplines while at the same time has not been investigated
from a data security and privacy perspective. We consider a common use scenario
of multi-institution collaborative studies, such as in the form of research
consortia or networks as widely seen in genetics, epidemiology, social
sciences, etc. To make our privacy-enhancing solution practical, we demonstrate
a non-conventional and computationally efficient method leveraging distributing
computing and strong cryptography to provide comprehensive protection over
individual-level and summary data. Extensive empirical evaluation on several
studies validated the privacy guarantees, efficiency and scalability of our
proposal. We also discuss the practical implications of our solution for
large-scale studies and applications from various disciplines, including
genetic and biomedical studies, smart grid, network analysis, etc
HandiVote: simple, anonymous, and auditable electronic voting
We suggest a set of procedures utilising a range of technologies by which a major democratic deïŹcit of modern society can be addressed. The mechanism, whilst it makes limited use of cryptographic techniques in the background, is based around objects and procedures with which voters are currently familiar. We believe that this holds considerable potential for the extension of democratic participation and control
Cryptographic security mechanism of the next generation digital tachograph system
JRC is in the process of evaluating the impact of update of the cryptographic security mechanisms for the next generation Digital Tachograph.
The purpose of this document is to give background information about the cryptographic security mechanisms and vulnerabilities regarding the security mechanisms of the current Digital Tachograph System along with suggestions for the next generation Digital Tachograph security mechanisms.
This document can be referred as an important reference to update the technical appendixes of the Tachograph regulation.JRC.G.7-Digital Citizen Securit
Personal Data Security: Divergent Standards in the European Union and the United States
This Note argues that the U.S. Government should discontinue all attempts to establish EES as the de facto encryption standard in the United States because the economic disadvantages associated with widespread implementation of EES outweigh the advantages this advanced data security system provides. Part I discusses the EU\u27s legislative efforts to ensure personal data security and analyzes the evolution of encryption technology in the United States. Part II examines the methods employed by the U.S. Government to establish EES as the de facto U.S. encryption standard. Part III argues that the U.S. Government should terminate its effort to establish EES as the de facto U.S. encryption standard and institute an alternative standard that ensures continued U.S. participation in the international marketplace
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