112,032 research outputs found
Brief History of Quantum Cryptography: A Personal Perspective
Quantum cryptography is the only approach to privacy ever proposed that
allows two parties (who do not share a long secret key ahead of time) to
communicate with provably perfect secrecy under the nose of an eavesdropper
endowed with unlimited computational power and whose technology is limited by
nothing but the fundamental laws of nature. This essay provides a personal
historical perspective on the field. For the sake of liveliness, the style is
purposely that of a spontaneous after-dinner speech.Comment: 14 pages, no figure
Quantum Key Distribution
This chapter describes the application of lasers, specifically diode lasers,
in the area of quantum key distribution (QKD). First, we motivate the
distribution of cryptographic keys based on quantum physical properties of
light, give a brief introduction to QKD assuming the reader has no or very
little knowledge about cryptography, and briefly present the state-of-the-art
of QKD. In the second half of the chapter we describe, as an example of a
real-world QKD system, the system deployed between the University of Calgary
and SAIT Polytechnic. We conclude the chapter with a brief discussion of
quantum networks and future steps.Comment: 20 pages, 12 figure
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The driving factors of continuance online shopping: Gender differences in behaviour among students in Saudi Arabia
This study proposes a revised technology acceptance model that integrates expectation confirmation theory to measure student gender differences with regard to continuance online shopping intentions in Saudi Arabia. The 234-respondent sample consists of 61.5% women and 38.5% men. A structural equation model confirms model fit.
Perceived usefulness, enjoyment, and subjective norms are determinants of online shopping continuance in Saudi Arabia. Both male and female groups are equivalent. The structural weights are also largely equivalent, but the regression paths from subjective norms to enjoyment and subjective norms to continuance intention (in the men sample) and perceived usefulness to continuous intention (in the women sample) are not supported.
The model was operationally generalized across the whole of Saudi Arabia. This research moves beyond online shopping intentions and includes factors affecting online shopping continuance. The research model explains 71% of the intention to continue shopping online.
This research suggests that online strategies cannot ignore either the direct or indirect gender differences on continuance intentions in Saudi Arabia. The model can be generalized across Saudi Arabia
Toward designing a quantum key distribution network simulation model
As research in quantum key distribution network technologies grows larger and more complex, the need for highly accurate and scalable simulation technologies becomes important to assess the practical feasibility and foresee difficulties in the practical implementation of theoretical achievements. In this paper, we described the design of simplified simulation environment of the quantum key distribution network with multiple links and nodes. In such simulation environment, we analyzed several routing protocols in terms of the number of sent routing packets, goodput and Packet Delivery Ratio of data traffic flow using NS-3 simulator
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Artificial Intelligence, International Competition, and the Balance of Power (May 2018)
World leaders, CEOs, and academics have suggested that a revolution in artificial intelligence is upon us. Are they right, and what will advances in artificial intelligence mean for international competition and the balance of power? This article evaluates how developments in artificial intelligence (AI) â advanced, narrow applications in particular â are poised to influence military power and international politics. It describes how AI more closely resembles âenablingâ technologies such as the combustion engine or electricity than a specific weapon. AIâs still-emerging developments make it harder to assess than many technological changes, especially since many of the organizational decisions about the adoption and uses of new technology that generally shape the impact of that technology are in their infancy. The article then explores the possibility that key drivers of AI development in the private sector could cause the rapid diffusion of military applications of AI, limiting first-mover advantages for innovators. Alternatively, given uncertainty about the technological trajectory of AI, it is also possible that military uses of AI will be harder to develop based on private-sector AI technologies than many expect, generating more potential first-mover advantages for existing powers such as China and the United States, as well as larger consequences for relative power if a country fails to adapt. Finally, the article discusses the extent to which U.S. military rhetoric about the importance of AI matches the reality of U.S. investments.LBJ School of Public Affair
E-Voting in an ubicomp world: trust, privacy, and social implications
The advances made in technology have unchained the user from the desktop into interactions where access is anywhere, anytime. In addition, the introduction of ubiquitous computing (ubicomp) will see further changes in how we interact with technology and also socially. Ubicomp evokes a near future in which humans will be surrounded by âalways-on,â unobtrusive, interconnected intelligent objects where information is exchanged seamlessly. This seamless exchange of information has vast social implications, in particular the protection and management of personal information. This research project investigates the concepts of trust and privacy issues specifically related to the exchange of e-voting information when using a ubicomp type system
Fiat-Shamir for highly sound protocols is instantiable
The FiatâShamir (FS) transformation (Fiat and Shamir, Crypto '86) is a popular paradigm for constructing very efficient non-interactive zero-knowledge (NIZK) arguments and signature schemes from a hash function and any three-move interactive protocol satisfying certain properties. Despite its wide-spread applicability both in theory and in practice, the known positive results for proving security of the FS paradigm are in the random oracle model only, i.e., they assume that the hash function is modeled as an external random function accessible to all parties. On the other hand, a sequence of negative results shows that for certain classes of interactive protocols, the FS transform cannot be instantiated in the standard model.
We initiate the study of complementary positive results, namely, studying classes of interactive protocols where the FS transform does have standard-model instantiations. In particular, we show that for a class of âhighly soundâ protocols that we define, instantiating the FS transform via a q-wise independent hash function yields NIZK arguments and secure signature schemes. In the case of NIZK, we obtain a weaker âq-boundedâ zero-knowledge flavor where the simulator works for all adversaries asking an a-priori bounded number of queries q; in the case of signatures, we obtain the weaker notion of random-message unforgeability against q-bounded random message attacks.
Our main idea is that when the protocol is highly sound, then instead of using random-oracle programming, one can use complexity leveraging. The question is whether such highly sound protocols exist and if so, which protocols lie in this class. We answer this question in the affirmative in the common reference string (CRS) model and under strong assumptions. Namely, assuming indistinguishability obfuscation and puncturable pseudorandom functions we construct a compiler that transforms any 3-move interactive protocol with instance-independent commitments and simulators (a property satisfied by the LapidotâShamir protocol, Crypto '90) into a compiled protocol in the CRS model that is highly sound. We also present a second compiler, in order to be able to start from a larger class of protocols, which only requires instance-independent commitments (a property for example satisfied by the classical protocol for quadratic residuosity due to Blum, Crypto '81). For the second compiler we require dual-mode commitments.
We hope that our work inspires more research on classes of (efficient) 3-move protocols where FiatâShamir is (efficiently) instantiable
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