687 research outputs found

    Data Minimisation in Communication Protocols: A Formal Analysis Framework and Application to Identity Management

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    With the growing amount of personal information exchanged over the Internet, privacy is becoming more and more a concern for users. One of the key principles in protecting privacy is data minimisation. This principle requires that only the minimum amount of information necessary to accomplish a certain goal is collected and processed. "Privacy-enhancing" communication protocols have been proposed to guarantee data minimisation in a wide range of applications. However, currently there is no satisfactory way to assess and compare the privacy they offer in a precise way: existing analyses are either too informal and high-level, or specific for one particular system. In this work, we propose a general formal framework to analyse and compare communication protocols with respect to privacy by data minimisation. Privacy requirements are formalised independent of a particular protocol in terms of the knowledge of (coalitions of) actors in a three-layer model of personal information. These requirements are then verified automatically for particular protocols by computing this knowledge from a description of their communication. We validate our framework in an identity management (IdM) case study. As IdM systems are used more and more to satisfy the increasing need for reliable on-line identification and authentication, privacy is becoming an increasingly critical issue. We use our framework to analyse and compare four identity management systems. Finally, we discuss the completeness and (re)usability of the proposed framework

    Server-based and server-less BYOD solutions to support electronic learning

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    Over the past 10 years, bring your own device has become an emerging practice across the commercial landscape and has empowered employees to conduct work-related business from the comfort of their own phone, tablet, or other personal electronic device. Currently in the Department of Defense, and specifically the Department of the Navy, no viable solution exists for the delivery of eLearning content to a service member's personal device that satisfy existing policies. The purpose of this thesis is to explore two potential solutions: a server-based method and a server-less method, both of which would allow Marines and Sailors to access eLearning course material by way of their personal devices. This thesis will test the feasibility and functionality of our server-based and server-less solutions by implementing a basic proof of concept for each. The intent is to provide a baseline from which further research and development can be conducted, and to demonstrate how these solutions present a low-risk environment that preserves government network security while still serving as a professional military education force multiplier. Both solutions, while demonstrated with limited prototypes, have the potential to finally introduce bring your own device into the Department of the Navy's eLearning realm.http://archive.org/details/serverbasedndser1094549343Captain, United States Marine CorpsCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

    Quantum Cryptography Beyond Quantum Key Distribution

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    Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation, secure two- and multi-party computation and delegated quantum computation. Quantum cryptography also studies the limitations and challenges resulting from quantum adversaries---including the impossibility of quantum bit commitment, the difficulty of quantum rewinding and the definition of quantum security models for classical primitives. In this review article, aimed primarily at cryptographers unfamiliar with the quantum world, we survey the area of theoretical quantum cryptography, with an emphasis on the constructions and limitations beyond the realm of QKD.Comment: 45 pages, over 245 reference

    The Cryptographic Security of the German Electronic Identity Card

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    In November 2010, the German government started to issue the new electronic identity card (eID) to its citizens. Besides its original utilization as a ’visual’ identification document, the eID card can be used by the cardholder to prove one’s identity at border control and to enhance security of authentication processes over the Internet, with the eID card serving as a token to reliably transmit personal data to service providers or terminals, respectively. To this end, the German Federal Office for Information Security (BSI) proposed several cryptographic protocols now deployed on the eID card. The Password Authenticated Connection Establishment (PACE) protocol secures the wireless communication between the eID card and the user’s local card reader, based on a cryptographically weak password like the PIN chosen by the card owner. Subsequently, the Extended Access Control (EAC) protocol is executed by the chip and the service provider to mutually authenticate and agree on a shared secret session key. This key is then used in the secure channel protocol, called Secure Messaging (SM). Finally, an optional protocol, called Restricted Identification (RI), provides a method to use pseudonyms such that they can be linked by individual service providers, but not across different service providers (even not by malicious ones). This thesis consists of two parts. First, we present the above protocols and provide a rigorous analysis on their security from a cryptographic point of view. We show that the Germen eID card provides reasonable security for authentication and exchange of sensitive information allaying concerns regarding its usage. In the second part of this thesis, we introduce two possible modifications to enhance the security of these protocols even further. Namely, we show how to (a) add to PACE an additional efficient chip authentication step, and (b) augment RI to allow also for signatures under pseudonyms

    An Analysis of Information Assurance Relating to the Department of Defense Radio Frequency Identification (RFID) Passive Network

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    The mandates for suppliers to commence Radio Frequency Identification tagging set by Wal-Mart and the Department of Defense is changing this long-time rumored technology into reality. Despite the many conveniences to automate and improve asset tracking this technology offers, consumer groups have obstinately opposed this adoption due to the perceived weaknesses in security and privacy of the network. While the heated debate between consumers and retailers continues, little to no research has addressed the implications of security on the Department of Defense Radio Frequency Identification network. This thesis utilized a historical analysis of Radio Frequency Identification literature to determine whether the current network design causes any serious security concerns adversaries could exploit. The research concluded that at the present level of implementation, there is little cause for concern over the security of the network, but as the network grows to its full deployment, more evaluation and monitoring of security issues will require further consideration

    The Frontiers of Technology in Warhead Verification

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    How might new technical verification capabilities enhance the prospects of success in future nuclear arms control negotiations? Both theory and evidence suggest that verification technologies can influence the dynamics of arms control negotiations by shaping and constraining the arguments and strategies that are available to the involved stakeholders. In the future, new technologies may help transcend the specific verification challenge of high-security warhead authentication, which is a verification capability needed in future disarmament scenarios that address fewer warheads, limit new categories of warheads, and involve nuclear weapons states other than the United States and Russia. Under these circumstances, the core challenge is maintaining the confidentiality of the classified information related to the warheads under inspection, while providing transparency in the verification process. This analysis focuses on a set of emerging warhead authentication approaches that rely on the cryptographic concept of zero-knowledge proofs and intend to solve the paradox between secrecy and transparency, making deeper reductions in warhead arsenals possible and thus facilitating future nuclear arms control negotiations

    Blockchain in Education

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    This report introduces the fundamental principles of the Blockchain focusing on its potential for the education sector. It explains how this technology may both disrupt institutional norms and empower learners. It proposes eight scenarios for the application of the Blockchain in an education context, based on the current state of technology development and deployment.JRC.B.4-Human Capital and Employmen

    Attacking and securing Network Time Protocol

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    Network Time Protocol (NTP) is used to synchronize time between computer systems communicating over unreliable, variable-latency, and untrusted network paths. Time is critical for many applications; in particular it is heavily utilized by cryptographic protocols. Despite its importance, the community still lacks visibility into the robustness of the NTP ecosystem itself, the integrity of the timing information transmitted by NTP, and the impact that any error in NTP might have upon the security of other protocols that rely on timing information. In this thesis, we seek to accomplish the following broad goals: 1. Demonstrate that the current design presents a security risk, by showing that network attackers can exploit NTP and then use it to attack other core Internet protocols that rely on time. 2. Improve NTP to make it more robust, and rigorously analyze the security of the improved protocol. 3. Establish formal and precise security requirements that should be satisfied by a network time-synchronization protocol, and prove that these are sufficient for the security of other protocols that rely on time. We take the following approach to achieve our goals incrementally. 1. We begin by (a) scrutinizing NTP's core protocol (RFC 5905) and (b) statically analyzing code of its reference implementation to identify vulnerabilities in protocol design, ambiguities in specifications, and flaws in reference implementations. We then leverage these observations to show several off- and on-path denial-of-service and time-shifting attacks on NTP clients. We then show cache-flushing and cache-sticking attacks on DNS(SEC) that leverage NTP. We quantify the attack surface using Internet measurements, and suggest simple countermeasures that can improve the security of NTP and DNS(SEC). 2. Next we move beyond identifying attacks and leverage ideas from Universal Composability (UC) security framework to develop a cryptographic model for attacks on NTP's datagram protocol. We use this model to prove the security of a new backwards-compatible protocol that correctly synchronizes time in the face of both off- and on-path network attackers. 3. Next, we propose general security notions for network time-synchronization protocols within the UC framework and formulate ideal functionalities that capture a number of prevalent forms of time measurement within existing systems. We show how they can be realized by real-world protocols (including but not limited to NTP), and how they can be used to assert security of time-reliant applications-specifically, cryptographic certificates with revocation and expiration times. Our security framework allows for a clear and modular treatment of the use of time in security-sensitive systems. Our work makes the core NTP protocol and its implementations more robust and secure, thus improving the security of applications and protocols that rely on time
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