57,852 research outputs found
Private Data Transfer over a Broadcast Channel
We study the following private data transfer problem: Alice has a database of
files. Bob and Cathy want to access a file each from this database (which may
or may not be the same file), but each of them wants to ensure that their
choices of file do not get revealed even if Alice colludes with the other user.
Alice, on the other hand, wants to make sure that each of Bob and Cathy does
not learn any more information from the database than the files they demand
(the identities of which will be unknown to her). Moreover, they should not
learn any information about the other files even if they collude.
It turns out that it is impossible to accomplish this if Alice, Bob, and
Cathy have access only to private randomness and noiseless communication links.
We consider this problem when a binary erasure broadcast channel with
independent erasures is available from Alice to Bob and Cathy in addition to a
noiseless public discussion channel. We study the
file-length-per-broadcast-channel-use rate in the honest-but-curious model. We
focus on the case when the database consists of two files, and obtain the
optimal rate. We then extend to the case of larger databases, and give upper
and lower bounds on the optimal rate.Comment: To be presented at IEEE International Symposium on Information Theory
(ISIT 2015), Hong Kon
On the Oblivious Transfer Capacity of the Degraded Wiretapped Binary Erasure Channel
We study oblivious transfer (OT) between Alice and Bob in the presence of an
eavesdropper Eve over a degraded wiretapped binary erasure channel from Alice
to Bob and Eve. In addition to the privacy goals of oblivious transfer between
Alice and Bob, we require privacy of Alice and Bob's private data from Eve. In
previous work we derived the OT capacity (in the honest-but-curious model) of
the wiretapped binary independent erasure channel where the erasure processes
of Bob and Eve are independent. Here we derive a lower bound on the OT capacity
in the same secrecy model when the wiretapped binary erasure channel is
degraded in favour of Bob.Comment: To be presented at the IEEE International Symposium on Information
Theory (ISIT 2015), Hong Kon
The Oblivious Transfer Capacity of the Wiretapped Binary Erasure Channel
We consider oblivious transfer between Alice and Bob in the presence of an
eavesdropper Eve when there is a broadcast channel from Alice to Bob and Eve.
In addition to the secrecy constraints of Alice and Bob, Eve should not learn
the private data of Alice and Bob. When the broadcast channel consists of two
independent binary erasure channels, we derive the oblivious transfer capacity
for both 2-privacy (where the eavesdropper may collude with either party) and
1-privacy (where there are no collusions).Comment: This is an extended version of the paper "The Oblivious Transfer
Capacity of the Wiretapped Binary Erasure Channel" to be presented at ISIT
201
Physical Layer Service Integration in 5G: Potentials and Challenges
High transmission rate and secure communication have been identified as the
key targets that need to be effectively addressed by fifth generation (5G)
wireless systems. In this context, the concept of physical-layer security
becomes attractive, as it can establish perfect security using only the
characteristics of wireless medium. Nonetheless, to further increase the
spectral efficiency, an emerging concept, termed physical-layer service
integration (PHY-SI), has been recognized as an effective means. Its basic idea
is to combine multiple coexisting services, i.e., multicast/broadcast service
and confidential service, into one integral service for one-time transmission
at the transmitter side. This article first provides a tutorial on typical
PHY-SI models. Furthermore, we propose some state-of-the-art solutions to
improve the overall performance of PHY-SI in certain important communication
scenarios. In particular, we highlight the extension of several concepts
borrowed from conventional single-service communications, such as artificial
noise (AN), eigenmode transmission etc., to the scenario of PHY-SI. These
techniques are shown to be effective in the design of reliable and robust
PHY-SI schemes. Finally, several potential research directions are identified
for future work.Comment: 12 pages, 7 figure
Quantum Anonymous Transmissions
We consider the problem of hiding sender and receiver of classical and
quantum bits (qubits), even if all physical transmissions can be monitored. We
present a quantum protocol for sending and receiving classical bits
anonymously, which is completely traceless: it successfully prevents later
reconstruction of the sender. We show that this is not possible classically. It
appears that entangled quantum states are uniquely suited for traceless
anonymous transmissions. We then extend this protocol to send and receive
qubits anonymously. In the process we introduce a new primitive called
anonymous entanglement, which may be useful in other contexts as well.Comment: 18 pages, LaTeX. Substantially updated version. To appear at
ASIACRYPT '0
Demand for satellite-provided domestic communications services up to the year 2000
Three fixed service telecommunications demand assessment studies were completed for NASA by The Western Union Telegraph Company and the U.S. Telephone and Telegraph Corporation. They provided forecasts of the total U.S. domestic demand, from 1980 to the year 2000, for voice, data, and video services. That portion that is technically and economically suitable for transmission by satellite systems, both large trunking systems and customer premises services (CPS) systems was also estimated. In order to provide a single set of forecasts a NASA synthesis of the above studies was conducted. The services, associated forecast techniques, and data bases employed by both contractors were examined, those elements of each judged to be the most appropriate were selected, and new forecasts were made. The demand for voice, data, and video services was first forecast in fundamental units of call-seconds, bits/year, and channels, respectively. Transmission technology characteristics and capabilities were then forecast, and the fundamental demand converted to an equivalent transmission capacity. The potential demand for satellite-provided services was found to grow by a factor of 6, from 400 to 2400 equivalent 36 MHz satellite transponders over the 20-year period. About 80 percent of this was found to be more appropriate for trunking systems and 20 percent CPS
Distributed storage manager system for synchronized and scalable AV services across networks
This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Hindawi Publishing CorporationThis paper provides an innovative solution, namely, the distributed storage manager that opens a new path for highly interactive and personalized services. The distributed storage manager provides an enhancement to the MHP storage management functionality acting as a value added middleware distributed across the network. The distributed storage manager system provides multiple protocol support for initializing and downloading both streamed and file-based content and provides optimum control mechanisms to organize the storing and retrieval of content that are remained accessible to other multiple heterogeneous devices
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