scispace - formally typeset
Search or ask a question
Topic

Keying

About: Keying is a research topic. Over the lifetime, 6598 publications have been published within this topic receiving 82943 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: Three unconventional approaches to keying variable management are presented and the characteristics of an urban UHF radio channel, determined by mutual sounding, as the cryptovariable are proposed.
Abstract: We present three unconventional approaches to keying variable management. The first approach is based on using a public key cryptosystem (PKC) that is breakable in short, but on average less, time than it takes to set up an ultrawide bandwidth modem that is then used to transport a keying variable for a classical cryptosystem. The second concept proposes using the characteristics of an urban UHF radio channel, determined by mutual sounding, as the cryptovariable. The third concept encourages research into ill-conditioned problems as potentially fruitful ground for PKCs not based on finite field arithmetic. >

252 citations

01 Aug 2004
TL;DR: This document describes a key management scheme that can be used for real-time applications (both for peer-to-peer communication and group communication) and in particular, its use to support the Secure Real-time Transport Protocol is described in detail.
Abstract: This document describes a key management scheme that can be used for real-time applications (both for peer-to-peer communication and group communication) In particular, its use to support the Secure Real-time Transport Protocol is described in detail Security protocols for real-time multimedia applications have started to appear This has brought forward the need for a key management solution to support these protocols [STANDARDS-TRACK]

252 citations

Proceedings ArticleDOI
10 Apr 2011
TL;DR: This work presents a new secret key generation approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models and is highly scalable and can improve the analytical key bit generation rate by a couple of orders of magnitude.
Abstract: Recently, there has been great interest in physical layer security techniques that exploit the randomness of wireless channels for securely extracting cryptographic keys. Several interesting approaches have been developed and demonstrated for their feasibility. The state-of-the-art, however, still has much room for improving their practicality. This is because i) the key bit generation rate supported by most existing approaches is very low which significantly limits their practical usage given the intermittent connectivity in mobile environments; ii) existing approaches suffer from the scalability and flexibility issues, i.e., they cannot be directly extended to support efficient group key generation and do not suit for static environments. With these observations in mind, we present a new secret key generation approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models. The proposed approach enjoys a high key bit generation rate due to its efficient introduction of multiple randomized phase information within a single coherence time interval as the keying sources. The proposed approach also provides scalability and flexibility because it relies only on the transmission of periodical extensions of unmodulated sinusoidal beacons, which allows effective accumulation of channel phases across multiple nodes. The proposed scheme is thoroughly evaluated through both analytical and simulation studies. Compared to existing work that focus on pairwise key generation, our approach is highly scalable and can improve the analytical key bit generation rate by a couple of orders of magnitude.

251 citations

Proceedings ArticleDOI
22 Apr 2007
TL;DR: It is shown that for COFDM (coded OFDM) with QPSK (quadrature phase shift keying) modulation and a single LED, a BER of 2 times 10-5 is achieved for a distance of 90 cm between transmitter and receiver.
Abstract: White LEDs are set to penetrate many areas of everyday life. An interesting property of these devices (in addition to their lightening capabilities) is that they can be utilised for data transmission. In the past, primarily OOK (on-off keying) has been used for digital data modulation of such devices. OOK imposes limitations on the achievable data rates. Therefore, in this paper OFDM is considered in combination with higher order modulation schemes. A hardware demonstrator with an entire link chain (transmitter and receiver) is developed and measured BER (bit error ratio) results are reported. The system uses pilot sub-carriers to correct frequency synchronisation errors, training sequences for channel estimation and time synchronisation routines. Forward error correction (FEC) coding is used. It is shown that for COFDM (coded OFDM) with QPSK (quadrature phase shift keying) modulation and a single LED, a BER of 2 times 10-5 is achieved for a distance of 90 cm between transmitter and receiver.

243 citations

Posted Content
TL;DR: In this article, a quasi-orthogonal (QO) space-time block code with minimum decoding complexity (MDC-QO-STBC) was proposed.
Abstract: In this paper, we consider a quasi-orthogonal (QO) space-time block code (STBC) with minimum decoding complexity (MDC-QO-STBC). We formulate its algebraic structure and propose a systematic method for its construction. We show that a maximum-likelihood (ML) decoder for this MDC-QOSTBC, for any number of transmit antennas, only requires the joint detection of two real symbols. Assuming the use of a square or rectangular quadratic-amplitude modulation (QAM) or multiple phase-shift keying (MPSK) modulation for this MDC-QOSTBC, we also obtain the optimum constellation rotation angle, in order to achieve full diversity and optimum coding gain. We show that the maximum achievable code rate of these MDC-QOSTBC is 1 for three and four antennas and 3/4 for five to eight antennas. We also show that the proposed MDC-QOSTBC has several desirable properties, such as a more even power distribution among antennas and better scalability in adjusting the number of transmit antennas, compared with the coordinate interleaved orthogonal design (CIOD) and asymmetric CIOD (ACIOD) codes. For the case of an odd number of transmit antennas, MDC-QO-STBC also has better decoding performance than CIOD.

243 citations


Network Information
Related Topics (5)
Transmission (telecommunications)
171.3K papers, 1.2M citations
85% related
Optical fiber
167K papers, 1.8M citations
84% related
Wireless
133.4K papers, 1.9M citations
84% related
Network packet
159.7K papers, 2.2M citations
84% related
Wireless network
122.5K papers, 2.1M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023137
2022286
2021170
2020238
2019301
2018291