213,308 research outputs found
Building Secure and Anonymous Communication Channel: Formal Model and its Prototype Implementation
Various techniques need to be combined to realize anonymously authenticated
communication. Cryptographic tools enable anonymous user authentication while
anonymous communication protocols hide users' IP addresses from service
providers. One simple approach for realizing anonymously authenticated
communication is their simple combination, but this gives rise to another
issue; how to build a secure channel. The current public key infrastructure
cannot be used since the user's public key identifies the user. To cope with
this issue, we propose a protocol that uses identity-based encryption for
packet encryption without sacrificing anonymity, and group signature for
anonymous user authentication. Communications in the protocol take place
through proxy entities that conceal users' IP addresses from service providers.
The underlying group signature is customized to meet our objective and improve
its efficiency. We also introduce a proof-of-concept implementation to
demonstrate the protocol's feasibility. We compare its performance to SSL
communication and demonstrate its practicality, and conclude that the protocol
realizes secure, anonymous, and authenticated communication between users and
service providers with practical performance.Comment: This is a preprint version of our paper presented in SAC'14, March
24-28, 2014, Gyeongju, Korea. ACMSAC 201
Kak's three-stage protocol of secure quantum communication revisited: Hitherto unknown strengths and weaknesses of the protocol
Kak's three-stage protocol for quantum key distribution is revisited with
special focus on its hitherto unknown strengths and weaknesses. It is shown
that this protocol can be used for secure direct quantum communication.
Further, the implementability of this protocol in the realistic situation is
analyzed by considering various Markovian noise models. It is found that the
Kak's protocol and its variants in their original form can be implemented only
in a restricted class of noisy channels, where the protocols can be transformed
to corresponding protocols based on logical qubits in decoherence free
subspace. Specifically, it is observed that Kak's protocol can be implemented
in the presence of collective rotation and collective dephasing noise, but
cannot be implemented in its original form in the presence of other types of
noise, like amplitude damping and phase damping noise. Further, the performance
of the protocol in the noisy environment is quantified by computing average
fidelity under various noise models, and subsequently a set of preferred states
for secure communication in noisy environment have also been identified.Comment: Kak's protocol is not suitable for quantum cryptography in presence
of nois
Secure and energy-efficient multicast routing in smart grids
A smart grid is a power system that uses information and communication technology to operate, monitor, and control data flows between the power generating source and the end user. It aims at high efficiency, reliability, and sustainability of the electricity supply process that is provided by the utility centre and is distributed from generation stations to clients. To this end, energy-efficient multicast communication is an important requirement to serve a group of residents in a neighbourhood. However, the multicast routing introduces new challenges in terms of secure operation of the smart grid and user privacy. In this paper, after having analysed the security threats for multicast-enabled smart grids, we propose a novel multicast routing protocol that is both sufficiently secure and energy efficient.We also evaluate the performance of the proposed protocol by means of computer simulations, in terms of its energy-efficient operation
Simulation and Evaluation of CTP and Secure-CTP Protocols
The paper discusses characteristics and qualities of two routing protocols â Collection Tree Protocol and its secure modiïŹcation. The original protocol, as well as other protocols for wireless sensors, solves only problems of ra- dio communication and limited resources. Our design of the secure protocol tries to solve also the essential security ob- jectives. For the evaluation of properties of our protocol in large networks, a TOSSIM simulator was used. Our effort was to show the inïŹuence of the modiïŹcation of the routing protocol to its behavior and quality of routing trees. We have proved that adding security into protocol design does not necessarily mean higher demands for data transfer, power consumption or worse protocol efïŹciency. In the paper, we manifest that security in the protocol may be achieved with low cost and may offer similar performance as the original protocol
Kak's three-stage protocol of secure quantum communication revisited: Hitherto unknown strengths and weaknesses of the protocol
Kak's three-stage protocol for quantum key distribution is revisited with
special focus on its hitherto unknown strengths and weaknesses. It is shown
that this protocol can be used for secure direct quantum communication.
Further, the implementability of this protocol in the realistic situation is
analyzed by considering various Markovian noise models. It is found that the
Kak's protocol and its variants in their original form can be implemented only
in a restricted class of noisy channels, where the protocols can be transformed
to corresponding protocols based on logical qubits in decoherence free
subspace. Specifically, it is observed that Kak's protocol can be implemented
in the presence of collective rotation and collective dephasing noise, but
cannot be implemented in its original form in the presence of other types of
noise, like amplitude damping and phase damping noise. Further, the performance
of the protocol in the noisy environment is quantified by computing average
fidelity under various noise models, and subsequently a set of preferred states
for secure communication in noisy environment have also been identified.Comment: Kak's protocol is not suitable for quantum cryptography in presence
of nois
High-dimensional coherent one-way quantum key distribution
High-dimensional quantum key distribution (QKD) offers secure communication,
with secure key rates that surpass those achievable by QKD protocols utilizing
two-dimensional encoding. However, existing high-dimensional QKD protocols
require additional experimental resources, such as multiport interferometers
and multiple detectors, thus raising the cost of practical high-dimensional
systems and limiting their use. Here, we present and analyze a novel protocol
for arbitrary-dimensional QKD, that requires only the hardware of a standard
two-dimensional system. We provide security proofs against individual attacks
and coherent attacks, setting an upper and lower bound on the secure key rates.
Then, we test the new high-dimensional protocol in a standard two-dimensional
QKD system over a 40 km fiber link. The new protocol yields a two-fold
enhancement of the secure key rate compared to the standard two-dimensional
coherent one-way protocol, without introducing any hardware modifications to
the system. This work, therefore, holds great potential to enhance the
performance of already deployed time-bin QKD systems through a software update
alone. Furthermore, its applications extend across different encoding schemes
of QKD qudits
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