17,911 research outputs found
Eavesdropping on GSM: state-of-affairs
In the almost 20 years since GSM was deployed several security problems have
been found, both in the protocols and in the - originally secret -
cryptography. However, practical exploits of these weaknesses are complicated
because of all the signal processing involved and have not been seen much
outside of their use by law enforcement agencies.
This could change due to recently developed open-source equipment and
software that can capture and digitize signals from the GSM frequencies. This
might make practical attacks against GSM much simpler to perform.
Indeed, several claims have recently appeared in the media on successfully
eavesdropping on GSM. When looking at these claims in depth the conclusion is
often that more is claimed than what they are actually capable of. However, it
is undeniable that these claims herald the possibilities to eavesdrop on GSM
using publicly available equipment.
This paper evaluates the claims and practical possibilities when it comes to
eavesdropping on GSM, using relatively cheap hardware and open source
initiatives which have generated many headlines over the past year. The basis
of the paper is extensive experiments with the USRP (Universal Software Radio
Peripheral) and software projects for this hardware.Comment: 5th Benelux Workshop on Information and System Security (WISSec
2010), November 201
Using Signal Processing Tools for Regulation Analysis and Implementation
Regulators often face the challenge of designing and implementing rules that both, respond to the policy objectives and that can be clearly referred to the day-to-day operations and practices in the marketplace. In many cases, the actual codes end up being a cumbersome collection of conditions that are very difficult to evaluate and re-design. This paper suggests that some of the most commonly used tools in Signal Processing could offer a convenient vehicle for tackling these difficulties. By starting from a SIMULINK(R) model of the regulation of Banco de Mexico on the foreign exchange transactions of commercial banks, this paper offers an example of how those tools could be used in this context.
Plasmonic Metamaterials: Physical Background and Some Technological Applications
New technological frontiers appear every year, and few are as intriguing as the field of plasmonic metamaterials (PMMs). These uniquely designed materials use coherent electron oscillations to accomplish an astonishing array of tasks, and they present diverse opportunities in many scientific fields.
This paper consists of an explanation of the scientific background of PMMs and some technological applications of these fascinating materials. The physics section addresses the foundational concepts necessary to understand the operation of PMMs, while the technology section addresses various applications, like precise biological and chemical sensors, cloaking devices for several frequency ranges, nanoscale photovoltaics, experimental optical computing components, and superlenses that can surpass the diffraction limit of conventional optics
Reducing the Lower Bound on Market Interest Rates
This paper critically discusses three proposals to overcome the zero interest bound, which have recently been proposed by prominent economists. We trace back the historical origins of these proposals, reaching back to the late 19th century, and comment on their theoretical and practical deficiencies. We propose a much simpler method to spur real investment in times of a deep recession, based on long term central bank loans with low but non-negative base rates. With the prospect of decreasing default risks after the recession, this measure has a similar effect like negative base rates in time of crisis. We therefore hope to convey the message that the effects of the zero interest bound can at least be mitigated without substantially changing the existing monetary regime.negative interest rates, lower zero bound, monetary policy
POPE: Partial Order Preserving Encoding
Recently there has been much interest in performing search queries over
encrypted data to enable functionality while protecting sensitive data. One
particularly efficient mechanism for executing such queries is order-preserving
encryption/encoding (OPE) which results in ciphertexts that preserve the
relative order of the underlying plaintexts thus allowing range and comparison
queries to be performed directly on ciphertexts. In this paper, we propose an
alternative approach to range queries over encrypted data that is optimized to
support insert-heavy workloads as are common in "big data" applications while
still maintaining search functionality and achieving stronger security.
Specifically, we propose a new primitive called partial order preserving
encoding (POPE) that achieves ideal OPE security with frequency hiding and also
leaves a sizable fraction of the data pairwise incomparable. Using only O(1)
persistent and non-persistent client storage for
, our POPE scheme provides extremely fast batch insertion
consisting of a single round, and efficient search with O(1) amortized cost for
up to search queries. This improved security and
performance makes our scheme better suited for today's insert-heavy databases.Comment: Appears in ACM CCS 2016 Proceeding
The Impact of Channel Feedback on Opportunistic Relay Selection for Hybrid-ARQ in Wireless Networks
This paper presents a decentralized relay selection protocol for a dense
wireless network and describes channel feedback strategies that improve its
performance. The proposed selection protocol supports hybrid
automatic-repeat-request transmission where relays forward parity information
to the destination in the event of a decoding error. Channel feedback is
employed for refining the relay selection process and for selecting an
appropriate transmission mode in a proposed adaptive modulation transmission
framework. An approximation of the throughput of the proposed adaptive
modulation strategy is presented, and the dependence of the throughput on
system parameters such as the relay contention probability and the adaptive
modulation switching point is illustrated via maximization of this
approximation. Simulations show that the throughput of the proposed selection
strategy is comparable to that yielded by a centralized selection approach that
relies on geographic information.Comment: 30 pages, 9 figures, submitted to the IEEE Transactions on Vehicular
Technology, revised March 200
A Simulation Study of an ASEAN Monetary Union (Replaces CentER DP 2010-100)
This paper analyzes some pros and cons of a monetary union for the ASEAN1 countries, excluding Myanmar. We estimate a stylized open-economy dynamic general equilibrium model for the ASEAN countries. Using the framework of linear quadratic differential games, we contrast the potential gains or losses for these countries due to economic shocks, in case they maintain their status-quo, they coordinate their monetary and/or fiscal policies, or form a monetary union. Assuming for all players open-loop information, we conclude that there are substantial gains from cooperation of monetary authorities. We also find that whether a monetary union improves upon monetary cooperation depends on the type of shocks and the extent of fiscal policy cooperation. Results are based both on a theoretical study of the structure of the estimated model and a simulation study.ASEAN economic integration;monetary union;linear quadratic differential games;open-loop information structure
- …