20 research outputs found

    A secure and private RFID authentication protocol based on quadratic residue

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    Radio Frequency IDentification based systems are getting pervasively deployed in many real-life applications in various settings for identification and authentication of remote objects. However, the messages that are transmitted over a insecure channel, are vulnerable to security and privacy concerns such as data privacy, location privacy of tag owner and etc. Recently, Yeh et al.'s proposed a RFID authentication protocol based on quadratic residue which is claimed to provide location privacy and prevent possible attacks. In this paper, we formally analyzed the protocol and we proved that the protocol provides destructive privacy according to Vaudenay privacy model. Moreover, we proposed a unilateral authentication protocol and we prove that our protocol satisfies higher privacy level such as narrow strong privacy. Besides, we proposed an enhanced version of our proposed protocol, which has same privacy level as Yeh at al protocol, but has reader authentication against stronger adversaries. Furthermore, the enhanced version of our protocol uses smaller number of cryptographic operations when compared to Yeh at al protocol and it is also cost efficient at the server and tag side and requires O(1) complexity to identify a RFID tag

    Security and privacy in RFID systems

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    RFID is a leading technology that has been rapidly deployed in several daily life applications such as payment, access control, ticketing, e-passport, supply-chain, etc. An RFID tag is an electronic label that can be attached to an object/individual in order to identify or track the object/individual through radio waves. Security and privacy are two major concerns in several applications as the tags are required to provide a proof of identity. The RFID tags are generally not tamper-resistant against strong adversarial attacks. They also have limited computational resources. Therefore, the design of a privacy preserving and cost-effective RFID authentication protocol is a very challenging task for industrial applications. Moreover, RFID systems are also vulnerable to relay attacks (i.e., mafia, terrorist and distance frauds) when they are used for authentication purposes. Distance bounding protocols are particularly designed as a countermeasure against these attacks. These protocols aim to ensure that the tags are in a bounded area by measuring the round-trip delays during a rapid challenge-response exchange of short authentication messages. Several RFID distance bounding protocols have been proposed recently in the literature. However, none of them provides the ideal security against the terrorist fraud. Besides, the requirements of low resources and inefficient data management trigger to make use of cloud computing technology in RFID authentication systems. However, as more and more information on individuals and companies is placed in the cloud, concerns about data safety and privacy raise. Therefore, while integrating cloud services into RFID authentication systems, the privacy of tag owner against the cloud must also be taken into account. Motivated by this need, this dissertation contributes to the design of algorithms and protocols aimed at dealing with the issues explained above. First of all, we introduce two privacy models for RFID authentication protocols based on Physically Unclonable Functions (PUF). We propose several authentication protocols in order to demonstrate these models. Moreover, we study distance bounding protocols having bit-wise fast phases and no final signature. We give analysis for the optimal security limits of the distance bounding protocols. Furthermore, we propose a novel RFID distance bounding protocol based on PUFs and it satisfies the highest security levels. Finally, we provide a new security and privacy model for integrating cloud computing into RFID systems. For the sake of demonstration of this model, we also propose two RFID authentication protocols that require various computational resources and provide different privacy levels

    New event detection and tracking in Turkish

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    Ankara : The Department of Computer Engineering and the Institute of Engineering and Science of Bilkent University, 2009.Thesis (Master's) -- Bilkent University, 2009.Includes bibliographical references leaves 66-73.The amount of information and the number of information resources on the Internet have been growing rapidly for over a decade. This is also true for on-line news and news providers. To overcome information overload news consumers prefer to track the topics that they are interested in. Topic detection and tracking (TDT) applications aim to organize the temporally ordered stories of a news stream according to the events. Two major problems in TDT are new event detection (NED) and topic tracking (TT). These problems respectively focus on finding the first stories of previously unseen new events and all subsequent stories on a certain topic defined by a small number of initial stories. In this thesis, the NED and TT problems are investigated in detail using the first large-scale test collection (BilCol2005) developed by Bilkent Information Retrieval Group. The collection contains 209,305 documents from the entire year of 2005 and involves several events in which eighty of them are annotated by humans. The experimental results show that a simple word truncation stemming method can statistically compete with a sophisticated stemming approach that pays attention to the morphological structure of the language. Our statistical findings illustrate that word stopping and the contents of the associated stopword list are important and removing the stopwords from content can significantly improve the system performance. We demonstrate that the confidence scores of two different similarity measures can be combined in a straightforward manner for improving the effectiveness.Kardaş, SüleymanM.S

    An efficient and private RFID authentication protocol supporting ownership transfer

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    Radio Frequency IDentification (RFID) systems are getting pervasively deployed in many daily life applications. But this increased usage of RFID systems brings some serious problems together, security and privacy. In some applications, ownership transfer of RFID labels is sine qua non need. Specifically, the owner of RFID tag might be required to change several times during its lifetime. Besides, after ownership transfer, the authentication protocol should also prevent the old owner to trace the tags and disallow the new owner to trace old transactions of the tags. On the other hand, while achieving privacy and security concerns, the computation complexity should be considered. In order to resolve these issues, numerous authentication protocols have been proposed in the literature. Many of them failed and their computation load on the server side is very high. Motivated by this need, we propose an RFID mutual authentication protocol to provide ownership transfer. In our protocol, the server needs only a constant-time complexity for identification when the tag and server are synchronized. In case of ownership transfer, our protocol preserves both old and new owners’ privacy. Our protocol is backward untraceable against a strong adversary who compromise tag, and also forward untraceable under an assumption

    Optimal security limits of RFID distance bounding protocols

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    In this paper, we classify the RFID distance bounding protocols having bitwise fast phases and no final signature. We also give the theoretical security bounds for two specific classes, leaving the security bounds for the general case as an open problem. As for the classification, we introduce the notion of k-previous challenge dependent (k-PCD) protocols where each response bit depends on the current and k-previous challenges and there is no final signature. We treat the case k = 0, which means each response bit depends only on the current challenge, as a special case and define such protocols as current challenge dependent (CCD) protocols. In general, we construct a trade-off curve between the security levels of mafia and distance frauds by introducing two generic attack algorithms. This leads to the conclusion that CCD protocols cannot attain the ideal security against distance fraud, i.e. 1/2, for each challenge-response bit, without totally losing the security against mafia fraud. We extend the generic attacks to 1-PCD protocols and obtain a trade-off curve for 1-PCD protocols pointing out that 1-PCD protocols can provide better security than CCD protocols. Thereby, we propose a natural extension of a CCD protocol to a 1-PCD protocol in order to improve its security. As a study case, we give two natural extensions of Hancke and Kuhn protocol to show how to enhance the security against either mafia fraud or distance fraud without extra cost

    Solving the Secure Storage Dilemma: An Efficient Scheme for Secure Deduplication with Privacy-Preserving Public Auditing

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    Existing cloud storage systems obtain the data in its plaintext form and perform conventional (server-side) deduplication mechanisms. However, disclosing the data to the cloud can potentially threaten the security and privacy of users, which is of utmost importance for a real-world cloud storage. This can be solved by secure deduplication mechanisms which enables the user to encrypt the data on the client-side (or via an encryption-as-a-service module) before uploading it to the cloud storage. Conventional client-side encryption solutions unfortunately make the deduplication more challenging. Privacy-preserving public auditing schemes, on the other hand, is also crucial because the clients outsource their data to the cloud providers and then permanently deletes the data from their local storages. In this paper, we consider the problem of secure deduplication over encrypted data stored in the cloud while supporting a privacy-preserving public auditing mechanism.We show that existing solutions cannot support both goals simultaneously due to the conflict of their security and efficiency requirements. In this respect, we present an efficient and secure deduplication scheme that supports client-side encryption and privacy-preserving public auditing. We finally show that our scheme provides better security and efficiency with respect to the very recently proposed existing schemes

    Security Attacks and Enhancements to Chaotic Map-Based RFID Authentication Protocols

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    Radio frequency identification (RFID) technology has been increasingly integrated into numerous applications for authentication of objects or individuals. However, because of its limited computation power, RFID technology may cause several security and privacy issues such as tracking the owner of the tag, cloning of the tags and etc. Recently, two chaotic map-based authentication protocols have been proposed for low-cost RFID tags in order to eliminate these issues. In this paper, we give the security analysis of these protocols and uncover their weaknesses. We prove that these protocols are vulnerable to tag tracing, tag impersonation and desynchronization attacks. The attack complexity of an adversary is polynomial and the success probability of these attacks are substantial. Moreover, we also propose an improved RFID authentication protocol that employs Chebyshev chaotic maps and complies with the EPC global Class 1 Generation 2 standard. Finally, we show that our protocol is resistant against those security issues

    Examination of a New Defense Mechanism: Honeywords

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    Past experiences show us that password breach is still one of the main methods of attackers to obtain personal or sensitive user data. Basically, assuming they have access to list of hashed passwords, they apply guessing attacks, i.e., attempt to guess a password by trying a large number of possibilities. We certainly need to change our way of thinking and use a novel and creative approach in order to protect our passwords. In fact, there are already novel attempts to provide password protection. The Honeywords system of Juels and Rivest is one of them which provides a detection mechanism for password breaches. Roughly speaking, they propose a method for password-based authentication systems where fake passwords, i.e., "honeywords" are added into a password file, in order to detect impersonation. Their solution includes an auxiliary secure server called "honeychecker" which can distinguish a user's real password among her honeywords and immediately sets off an alarm whenever a honeyword is used. However, they also pointed out that their system needs to be improved in various ways by highlighting some open problems. In this paper, after revisiting the security of their proposal, we specifically focus on and aim to solve a highlighted open problem, i.e., active attacks where the adversary modifies the code running on either the login server or the honeychecker

    A framework for analyzing RFID distance bounding protocols

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    Many distance bounding protocols appropriate for the RFID technology have been proposed recently. Unfortunately, they are commonly designed without any formal approach, which leads to inaccurate analyzes and unfair comparisons. Motivated by this need, we introduce a unied framework that aims to improve analysis and design of distance bounding protocols. Our framework includes a thorough terminology about the frauds, adversary, and prover, thus disambiguating many misleading terms. It also explores the adversary's capabilities and strategies, and addresses the impact of the prover's ability to tamper with his device. It thus introduces some new concepts in the distance bounding domain as the black-box and white-box models, and the relation between the frauds with respect to these models. The relevancy and impact of the framework is nally demonstrated on a study case: Munilla-Peinado distance bounding protocol

    Norwegian internet voting protocol revisited: ballot box and receipt generator are allowed to collude

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. open access articleNorway experienced internet voting in 2011 and 2013 for municipal and parliamentary elections, respectively. Its security depends on the assumptions that the involving organizations are completely independent, reliable, and the receipt codes are securely sent to the voters. In this paper, we point out the following aspects: - The vote privacy of the Norwegian scheme is violated if Ballot Box and Receipt Generator cooperate because the private key of Decryption Service can be obtained by the two former players. We propose a solution to avoid this issue without adding new players. - To assure the correctness, the receipt codes are sent to the voters over a pre‐channel (postal service) and a post‐channel (Short Message Service [SMS]). However, by holding both SMS and the postal receipt code, a voter can reveal his vote even after the elections. Albeit revoting is a fairly well solution for coercion or concealment, intentional vote revealing is still a problem. We suggest SMS only for notification of vote submission. - In case the codes are falsely generated or the pre‐channel is not secure, a vote can be counted for a different candidate without detection. We propose a solution in which voters verify the integrity of the postal receipt codes
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