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  • 1.
    Aamir, Syed Ahmed
    Linköpings universitet. Linköpings universitet, Institutionen för systemteknik.
    A 65nm, Low Voltage, Fully Differential, SC Programmable Gain Amplifier for Video AFE2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Due to rapid growth of home entertainment consumer market, video technology has been continuously pushed to deliver sharper pictures with higher resolution. This has brought about stringent requirements on the video analog front end, which often coupled with the low power and low voltage regulations had to deal with short channel effects of the deep submicron CMOS processes.

    This thesis presents the design of a fully differential programmable gain amplifier, as a subcircuit of a larger video digitizing IC designed at division of Electronic Systems. The switched capacitor architecture of the PGA does not only buffer the signal, but performs compensation for the sync-tip of analog video signal.

    The pseudo differential OTA eliminates tail current source and maintains high signal swing and has efficient common mode feedforward mechanism. When coupled with a similar stage provides inherent common moode feedback without using an additional SC-CMFB block.

    The PGA has been implemented using a 65 nm digital CMOS process. Expected difficulties in a 1.2 V OTA design make themselves evident in 65 nm, which is why cascaded OTA structures were inevitable for attaining gain specification of 60 dB. Nested Miller compensation with a pole shifting source follower, stabilizes the multipole system. The final circuit attains up to 200 MHz bandwidth and maintains high output swing of 0.85 V. High slew rate and good common mode and power supply rejection are observed. Noise requirements require careful design of input differential stage. Although output source follower stabilized the system, it reduces significant bandwidth and adds to second order non-linearity.

  • 2.
    Aamir, Syed Ahmed
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, J Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A 1.2-V pseudo-differential OTA with common-mode feedforward in 65-nm CMOS2010Inngår i: Proceedings of the 17th IEEE International Conference on Electronics, Circuits, and Systems, Institute of Electrical and Electronics Engineers (IEEE), 2010, s. 29-32Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work, we describe the implementation of a 1. 2-V pseudo-differential operational transconductance amplifier (OTA) with common-mode feedforward (CMFF) and inher­ent common-mode feedback (CMFB) in a 65-nm, digital CMOS process. The OTA architecture provides an inher­ent CMFB when cascaded OTA structures are utilized andthis work has studied a cascaded amplifier consisting of fourstages. Due to the low-gain using core 65-nm circuit de­vices, the overall gain must be distributed on all four stages to acquire a gain of more than 60 dB, while maintaining a-3-dB bandwidth of 200 MHz. To achieve high gain, we propose using a modified, positive-feedback, cross-coupled input differential stage. The modified OTA achieves a high output swing of ± 0.85 V due to only two stacked transistors, 88 dB DC gain and a third-order harmonic of -60 dB for 800 mVpp at 30 MHz. Further on, in a capacitive buffer configuration, we achieve a high slew rate of 1240 V/µS, -3-dB bandwidth of 509 MHz, signal-to-noise ratio of 63 dB while consuming 10.4 mW power.

  • 3.
    Aamir, Syed Ahmed
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, J Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A 500-MHz low-voltage programmable gain amplifier for HD video in 65-nm CMOS2010Inngår i: Proceedings of 28th IEEE Norchip Conference., NORCHIP'10, Tampere: www.ieee.org , 2010, s. 1-4Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work describes the implementation of a 1.2-V programmable gain amplifier (PGA) for high-definition (HD) video digitizers in a 65-nm digital CMOS process. The “pseudo” switched-capacitor (SC) PGA architecture buffers the video signal, without switching, during the active video. The SC circuitry is used for setup of DC operating point during horizontal and vertical blanking periods. Additionally, it compensates for the `sync-tip' of analog video signals to an equal blanking level for increased dynamic range to the digitizer following the PGA. The operational transconductance amplifier (OTA) employed as main amplifier in the PGA is a pseudo-differential, positive-feedback input stage architecture with a common-mode feedforward (CMFF) technique. The common-mode feedback (CMFB) is provided once two OTAs are cascaded. Schematic-level simulation results show that the OTA maintains a -3-dB bandwidth of 550 MHz, while keeping the distortion HD3 at -60 dB for a 30-MHz, 850 mVpp high definition video signal. The 88 dB DC gain is distributed among four OTA stages and the overall, combined PGA achieves a signal-to-noise ratio of 63 dB. Due to only two stacked transistors, it achieves high output swing of ±0.85 V, 1240 V/μs slew rate while consuming 10.4 mW power.

  • 4.
    Abara, Precious Ugo
    et al.
    Univ Padua, Italy; Tech Univ Munich, Germany.
    Ticozzi, Francesco
    Univ Padua, Italy; Dartmouth Coll, NH 03755 USA.
    Altafini, Claudio
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    Spectral Conditions for Stability and Stabilization of Positive Equilibria for a Class of Nonlinear Cooperative Systems2018Inngår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 63, nr 2, s. 402-417Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nonlinear cooperative systems associated to vector fields that are concave or subhomogeneous describe well interconnected dynamics that are of key interest for communication, biological, economical, and neural network applications. For this class of positive systems, we provide conditions that guarantee existence, uniqueness and stability of strictly positive equilibria. These conditions can be formulated directly in terms of the spectral radius of the Jacobian of the system. If control inputs are available, then it is shown how to use state feedback to stabilize an equilibrium point in the interior of the positive orthant.

  • 5.
    Abarghouyi, Hadis
    et al.
    IUST, Iran; MTNi Co, Iran.
    Razavizadeh, S. Mohammad
    IUST, Iran.
    Björnson, Emil
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    QoE-Aware Beamforming Design for Massive MIMO Heterogeneous Networks2018Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, nr 9, s. 8315-8323Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the main goals of the future wireless networks is improving the users quality of experience (QoE). In this paper, we consider the problem of the QoE-based resource allocation in the downlink of a massive multiple-input multiple-output heterogeneous network. The network consists of a macrocell with a number of small cells embedded in it. The small cells base stations (BSs) are equipped with a few antennas, while the macro BS is equipped with a massive number of antennas. We consider the two services Video and Web Browsing and design the beamforming vectors at the BSs. The objective is to maximize the aggregated mean opinion score (MOS) of the users under constraints on the BSs powers and the required quality of service of the users. We also consider extra constraints on the QoE of users to more strongly enforce the QoE in the beamforming design. To reduce the complexity of the optimization problem, we suggest suboptimal and computationally efficient solutions. Our results illustrate that increasing the number of antennas at the BSs and also increasing the number of small cells antennas in the network leads to a higher user satisfaction.

  • 6. Bestill onlineKjøp publikasjonen >>
    Abbas, Muhammad
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    On the Implementation of Integer and Non-Integer Sampling Rate Conversion2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The main focus in this thesis is on the aspects related to the implementation of integer and non-integer sampling rate conversion (SRC). SRC is used in many communication and signal processing applications where two signals or systems having different sampling rates need to be interconnected. There are two basic approaches to deal with this problem. The first is to convert the signal to analog and then re-sample it at the desired rate. In the second approach, digital signal processing techniques are utilized to compute values of the new samples from the existing ones. The former approach is hardly used since the latter one introduces less noise and distortion. However, the implementation complexity for the second approach varies for different types of conversion factors. In this work, the second approach for SRC is considered and its implementation details are explored. The conversion factor in general can be an integer, a ratio of two integers, or an irrational number. The SRC by an irrational numbers is impractical and is generally stated for the completeness. They are usually approximated by some rational factor.

    The performance of decimators and interpolators is mainly determined by the filters, which are there to suppress aliasing effects or removing unwanted images. There are many approaches for the implementation of decimation and interpolation filters, and cascaded integrator comb (CIC) filters are one of them. CIC filters are most commonly used in the case of integer sampling rate conversions and often preferred due to their simplicity, hardware efficiency, and relatively good anti-aliasing (anti-imaging) characteristics for the first (last) stage of a decimation (interpolation). The multiplierless nature, which generally yields to low power consumption, makes CIC filters well suited for performing conversion at higher rate. Since these filters operate at the maximum sampling frequency, therefore, are critical with respect to power consumption. It is therefore necessary to have an accurate and efficient ways and approaches that could be utilized to estimate the power consumption and the important factors that are contributing to it. Switching activity is one such factor. To have a high-level estimate of dynamic power consumption, switching activity equations in CIC filters are derived, which may then be used to have an estimate of the dynamic power consumption. The modeling of leakage power is also included, which is an important parameter to consider since the input sampling rate may differ several orders of magnitude. These power estimates at higher level can then be used as a feed-back while exploring multiple alternatives.

    Sampling rate conversion is a typical example where it is required to determine the values between existing samples. The computation of a value between existing samples can alternatively be regarded as delaying the underlying signal by a fractional sampling period. The fractional-delay filters are used in this context to provide a fractional-delay adjustable to any desired value and are therefore suitable for both integer and non-integer factors. The structure that is used in the efficient implementation of a fractional-delay filter is know as Farrow structure or its modifications. The main advantage of the Farrow structure lies in the fact that it consists of fixed finite-impulse response (FIR) filters and there is only one adjustable fractional-delay parameter, used to evaluate a polynomial with the filter outputs as coefficients. This characteristic of the Farrow structure makes it a very attractive structure for the implementation. In the considered fixed-point implementation of the Farrow structure, closed-form expressions for suitable word lengths are derived based on scaling and round-off noise. Since multipliers share major portion of the total power consumption, a matrix-vector multiple constant multiplication approach is proposed to improve the multiplierless implementation of FIR sub-filters.

    The implementation of the polynomial part of the Farrow structure is investigated by considering the computational complexity of different polynomial evaluation schemes. By considering the number of operations of different types, critical path, pipelining complexity, and latency after pipelining, high-level comparisons are obtained and used to short list the suitable candidates. Most of these evaluation schemes require the explicit computation of higher order power terms. In the parallel evaluation of powers, redundancy in computations is removed by exploiting any possible sharing at word level and also at bit level. As a part of this, since exponents are additive under multiplication, an ILP formulation for the minimum addition sequence problem is proposed.

    Delarbeid
    1. Power Estimation of Recursive and Non-Recursive CIC Filters Implemented in Deep-Submicron Technology
    Åpne denne publikasjonen i ny fane eller vindu >>Power Estimation of Recursive and Non-Recursive CIC Filters Implemented in Deep-Submicron Technology
    2010 (engelsk)Inngår i: Proceedings of International Conference on Green Circuits and Systems (ICGCS), 2010, Date: 21-23 June, 2010, IEEE , 2010, s. 221-225Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    The power modeling of different realizations of cascaded integrator-comb (CIC) decimation filters has been a subject of several recent works. In this work we have extended these with modeling of leakage power, which is an important factor since the input sample rate may differ several orders of magnitude. Furthermore, we have pointed out the importance of the input wordlength on the comparison of recursive and nonrecursive implementations.

    sted, utgiver, år, opplag, sider
    IEEE, 2010
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-70451 (URN)10.1109/ICGCS.2010.5543063 (DOI)978-1-4244-6877-5 (ISBN)978-1-4244-6876-8 (ISBN)
    Konferanse
    International Conference on Green Circuits and Systems (ICGCS), June 21–23, Shanghai, China
    Tilgjengelig fra: 2011-09-20 Laget: 2011-09-08 Sist oppdatert: 2015-03-11bibliografisk kontrollert
    2. Switching Activity Estimation of CIC Filter Integrators
    Åpne denne publikasjonen i ny fane eller vindu >>Switching Activity Estimation of CIC Filter Integrators
    2010 (engelsk)Inngår i: Proceedings of Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics (PrimeAsia), 2010, Date:22-24 Sept. 2010, IEEE , 2010, s. 21-24Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this work, a method for estimation of the switching activity in integrators is presented. To achieve low power, it is always necessary to develop accurate and efficient methods to estimate the switching activity. The switching activities are then used to estimate the power consumption. In our work, the switching activity is first estimated for the general purpose integrators and then it is extended for the estimation of switching activity in cascaded integrators in CIC filters.

    sted, utgiver, år, opplag, sider
    IEEE, 2010
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-70452 (URN)10.1109/PRIMEASIA.2010.5604971 (DOI)978-1-4244-6736-5 (ISBN)978-1-4244-6735-8 (ISBN)
    Konferanse
    Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics (PrimeAsia), 22-24 September, Shanghai, China
    Merknad
    ©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. MUHAMMAD ABBAS and Oscar Gustafsson, Switching Activity Estimation of CIC Filter Integrators, 2010, Asia Pacific Conf. on Postgraduate Research in Microelectronics and Electronics, Shanghai, China. http://dx.doi.org/10.1109/PRIMEASIA.2010.5604971 Tilgjengelig fra: 2011-09-20 Laget: 2011-09-08 Sist oppdatert: 2015-03-11bibliografisk kontrollert
    3. Scaling of fractional delay filters based on the Farrow structure
    Åpne denne publikasjonen i ny fane eller vindu >>Scaling of fractional delay filters based on the Farrow structure
    2009 (engelsk)Inngår i: Proceedings of IEEE International Symposium on Circuits and Systems, 2009. ISCAS 2009, Piscataway: IEEE , 2009, s. 489-492Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this work we consider scaling of fractional delay filters using the Farrow structure. Based on the observation that the subfilters approximate the Taylor expansion of a differentiator, we derive estimates of the L2-norm scaling values at the outputs of each subfilter as well as at the inputs of each delay multiplier. The scaling values can then be used to derive suitable wordlengths in a fixed-point implementation.

    sted, utgiver, år, opplag, sider
    Piscataway: IEEE, 2009
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-51070 (URN)10.1109/ISCAS.2009.5117792 (DOI)000275929800123 ()978-1-4244-3827-3 (ISBN)
    Konferanse
    IEEE International Symposium on Circuits and Systems, 24-27 May 2009, Taipei,Taiwan
    Tilgjengelig fra: 2009-10-15 Laget: 2009-10-15 Sist oppdatert: 2018-09-01bibliografisk kontrollert
    4. Computational and Implementation Complexity of Polynomial Evaluation Schemes
    Åpne denne publikasjonen i ny fane eller vindu >>Computational and Implementation Complexity of Polynomial Evaluation Schemes
    2011 (engelsk)Inngår i: Proceedings of NORCHIP, 2011 Date:14-15 Nov. 2011, IEEE conference proceedings, 2011, s. 1-6Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this work, we consider the computational complexity of different polynomial evaluation schemes. By considering the number of operations of different types, critical path, pipelining complexity, and latency after pipelining, high-level comparisons are obtained. These can then be used to short list suitable candidates for an implementation given the specifications. Not only multiplications are considered, but they are divided into data-data multiplications, squarers, and data-coefficient multiplications, as the latter can be optimized depending on implementation architecture and application.

    sted, utgiver, år, opplag, sider
    IEEE conference proceedings, 2011
    Emneord
    Adders, Computer architecture, Delay, Filtering algorithms, ISO, Pipeline processing, Polynomials
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-73935 (URN)10.1109/NORCHP.2011.6126735 (DOI)978-1-4577-0515-1 (ISBN)978-1-4577-0514-4 (ISBN)
    Konferanse
    NORCHIP 2011. The Nordic Microelectronics event, 29th Norchip Conference 14-15 November 2011, Lund, Sweden
    Tilgjengelig fra: 2012-01-17 Laget: 2012-01-17 Sist oppdatert: 2015-03-11bibliografisk kontrollert
    5. Low-Complexity Parallel Evaluation of Powers Exploiting Bit-Level Redundancy
    Åpne denne publikasjonen i ny fane eller vindu >>Low-Complexity Parallel Evaluation of Powers Exploiting Bit-Level Redundancy
    2010 (engelsk)Inngår i: Conference Record of the Forty Fourth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2010, 7-10 Nov. 2010 / [ed] Michael B. Matthews, Washington, DC, USA: IEEE Computer Society , 2010, s. 1168-1172Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this work, we investigate the problem of computing any requested set of power terms in parallel using summations trees. This problem occurs in applications like polynomial approximation, Farrow filters (polynomial evaluation part) etc. In the proposed technique, the partial product of each power term is initially computed independently. A redundancy check is then made in each and among all partial products matrices at bit level. The redundancy here relates to the fact that same three partial products may be present in more than one columns, and, hence, can be mapped to the same full adder. The proposed algorithm is tested for different sets of powers and wordlengths to exploit the sharing potential.

    sted, utgiver, år, opplag, sider
    Washington, DC, USA: IEEE Computer Society, 2010
    Serie
    Asilomar Conference on Signals, Systems and Computers. Conference Record, ISSN 1058-6393
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-70453 (URN)10.1109/ACSSC.2010.5757714 (DOI)978-1-4244-9722-5 (ISBN)
    Konferanse
    Signals, Systems and Computers (ASILOMAR), 2010, 7-10 Nov. 2010 , Pacific Grove, CA, USA
    Tilgjengelig fra: 2011-09-20 Laget: 2011-09-08 Sist oppdatert: 2015-03-11bibliografisk kontrollert
    6. Integer Linear Programming Modeling of Addition Sequences With Additional Constraints for Evaluation of Power Terms
    Åpne denne publikasjonen i ny fane eller vindu >>Integer Linear Programming Modeling of Addition Sequences With Additional Constraints for Evaluation of Power Terms
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this work, an integer linear programming (ILP) based model is proposed for the computation of a minimal cost addition sequence for a given set of integers. Since exponents are additive under multiplication, the minimal length addition sequence will provide an optimal solution for the evaluation of a requested set of power terms. This in turn finds application in, e.g., window-based exponentiation for cryptography and polynomial evaluation. Not only is an optimal model proposed, the model is extended to consider different costs for multipliers and squarers as well as controlling the depth of the resulting addition sequence.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-73936 (URN)
    Tilgjengelig fra: 2012-01-17 Laget: 2012-01-17 Sist oppdatert: 2015-03-11bibliografisk kontrollert
    7. Switching Activity Estimation of DDFS Phase Accumulators
    Åpne denne publikasjonen i ny fane eller vindu >>Switching Activity Estimation of DDFS Phase Accumulators
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this letter, equations for the one’s probability and switching activities for direct digital frequency synthesis (DDFS) phase accumulators are derived. These results are useful for obtaining good accuracy estimated of both leakage and dynamic power consumption for the phase accumulator and the phase-to-magnitude converter.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-73937 (URN)
    Tilgjengelig fra: 2012-01-17 Laget: 2012-01-17 Sist oppdatert: 2015-03-11bibliografisk kontrollert
  • 7.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Computational and Implementation Complexity of Polynomial Evaluation Schemes2011Inngår i: Proceedings of NORCHIP, 2011 Date:14-15 Nov. 2011, IEEE conference proceedings, 2011, s. 1-6Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work, we consider the computational complexity of different polynomial evaluation schemes. By considering the number of operations of different types, critical path, pipelining complexity, and latency after pipelining, high-level comparisons are obtained. These can then be used to short list suitable candidates for an implementation given the specifications. Not only multiplications are considered, but they are divided into data-data multiplications, squarers, and data-coefficient multiplications, as the latter can be optimized depending on implementation architecture and application.

  • 8.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Integer Linear Programming Modeling of Addition Sequences With Additional Constraints for Evaluation of Power TermsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this work, an integer linear programming (ILP) based model is proposed for the computation of a minimal cost addition sequence for a given set of integers. Since exponents are additive under multiplication, the minimal length addition sequence will provide an optimal solution for the evaluation of a requested set of power terms. This in turn finds application in, e.g., window-based exponentiation for cryptography and polynomial evaluation. Not only is an optimal model proposed, the model is extended to consider different costs for multipliers and squarers as well as controlling the depth of the resulting addition sequence.

  • 9.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Switching Activity Estimation of CIC Filter Integrators2010Inngår i: Proceedings of Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics (PrimeAsia), 2010, Date:22-24 Sept. 2010, IEEE , 2010, s. 21-24Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work, a method for estimation of the switching activity in integrators is presented. To achieve low power, it is always necessary to develop accurate and efficient methods to estimate the switching activity. The switching activities are then used to estimate the power consumption. In our work, the switching activity is first estimated for the general purpose integrators and then it is extended for the estimation of switching activity in cascaded integrators in CIC filters.

  • 10.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Switching Activity Estimation of DDFS Phase AccumulatorsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this letter, equations for the one’s probability and switching activities for direct digital frequency synthesis (DDFS) phase accumulators are derived. These results are useful for obtaining good accuracy estimated of both leakage and dynamic power consumption for the phase accumulator and the phase-to-magnitude converter.

  • 11.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Blad, Anton
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Low-Complexity Parallel Evaluation of Powers Exploiting Bit-Level Redundancy2010Inngår i: Conference Record of the Forty Fourth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2010, 7-10 Nov. 2010 / [ed] Michael B. Matthews, Washington, DC, USA: IEEE Computer Society , 2010, s. 1168-1172Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work, we investigate the problem of computing any requested set of power terms in parallel using summations trees. This problem occurs in applications like polynomial approximation, Farrow filters (polynomial evaluation part) etc. In the proposed technique, the partial product of each power term is initially computed independently. A redundancy check is then made in each and among all partial products matrices at bit level. The redundancy here relates to the fact that same three partial products may be present in more than one columns, and, hence, can be mapped to the same full adder. The proposed algorithm is tested for different sets of powers and wordlengths to exploit the sharing potential.

  • 12.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Johansson, Håkan
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    On the Fixed-Point Implementation of Fractional-Delay Filters Based on the Farrow Structure2013Inngår i: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 60, nr 4, s. 926-937Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, the fixed-point implementation of adjustable fractional-delay filters using the Farrow structure is considered. Based on the observation that the sub-filters approximate differentiators, closed-form expressions for the L-2-norm scaling values at the outputs of each sub-filter as well as at the inputs of each delay multiplier are derived. The scaling values can then be used to derive suitable word lengths by also considering the round-off noise analysis and optimization. Different approaches are proposed to derive suitable word lengths including one based on integer linear programming, which always gives an optimal allocation. Finally, a new approach for multiplierless implementation of the sub-filters in the Farrow structure is suggested. This is shown to reduce register complexity and, for most word lengths, require less number of adders and subtracters when compared to existing approaches.

  • 13.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Johansson, Håkan
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Scaling of fractional delay filters based on the Farrow structure2009Inngår i: Proceedings of IEEE International Symposium on Circuits and Systems, 2009. ISCAS 2009, Piscataway: IEEE , 2009, s. 489-492Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work we consider scaling of fractional delay filters using the Farrow structure. Based on the observation that the subfilters approximate the Taylor expansion of a differentiator, we derive estimates of the L2-norm scaling values at the outputs of each subfilter as well as at the inputs of each delay multiplier. The scaling values can then be used to derive suitable wordlengths in a fixed-point implementation.

  • 14.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wanhammar, Lars
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Power Estimation of Recursive and Non-Recursive CIC Filters Implemented in Deep-Submicron Technology2010Inngår i: Proceedings of International Conference on Green Circuits and Systems (ICGCS), 2010, Date: 21-23 June, 2010, IEEE , 2010, s. 221-225Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The power modeling of different realizations of cascaded integrator-comb (CIC) decimation filters has been a subject of several recent works. In this work we have extended these with modeling of leakage power, which is an important factor since the input sample rate may differ several orders of magnitude. Furthermore, we have pointed out the importance of the input wordlength on the comparison of recursive and nonrecursive implementations.

  • 15.
    Abbas, Muhammad
    et al.
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Qureshi, Fahad
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Ullah Sheikh, Zaka
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Johansson, Håkan
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Johansson, Kenny
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Comparison of Multiplierless Implementation of Nonlinear-Phase Versus Linear-Phase FIR filters2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    FIR filters are often used because of their linear-phase response. However, there are certain applications where the linear-phase property is not required, such as signal energy estimation, but IIR filters can not be used due to the limitation of sample rate imposed by the recursive algorithm. In this work, we discuss multiplierless implementation of minimum order, and therefore nonlinear-phase, FIR filters and compare it to the linear-phase counterpart.

  • 16.
    Abdullah Jan, Mirza
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Ahsan, Mahmododfateh
    Linköpings universitet, Institutionen för systemteknik.
    Multi-View Video Transmission over the Internet2010Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    3D television using multiple views rendering is receiving increasing interest. In this technology a number of video sequences are transmitted simultaneously and provides a larger view of the scene or stereoscopic viewing experience. With two views stereoscopic rendition is possible. Nowadays 3D displays are available that are capable of displaying several views simultaneously and the user is able to see different views by moving his head.

    The thesis work aims at implementing a demonstration system with a number of simultaneous views. The system will include two cameras, computers at both the transmitting and receiving end and a multi-view display. Besides setting up the hardware, the main task is to implement software so that the transmission can be done over an IP-network.

    This thesis report includes an overview and experiences of similar published systems, the implementation of real time video, its compression, encoding, and transmission over the internet with the help of socket programming and finally the multi-view display in 3D format.  This report also describes the design considerations more precisely regarding the video coding and network protocols.

  • 17.
    Abellán, C.
    et al.
    ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.
    Acín, A.
    ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain / ICREA - Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain.
    Alarcón, A.
    Millennium Institute for Research in Optics, Universidad de Concepción, Universidad de Concepción, Concepción, Chile / Departamento de Ingeniería Eléctrica, Universidad de Concepción, Concepción, Chile.
    Alibart, O.
    Université Côte d’Azur, CNRS UMR 7010, Institut de Physique de Nice (INPHYNI), Nice, France.
    Andersen, C. K.
    Department of Physics, ETH Zurich,, Zurich, Switzerland.
    Andreoli, F.
    Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy.
    Beckert, A.
    Department of Physics, ETH Zurich,, Zurich, Switzerland.
    Beduini, F. A.
    ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.
    Bendersky, A.
    Departamento de Computación, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Investigación en Ciencias de la Comunicación (ICC), CONICET, Buenos Aires, Argentina.
    Bentivegna, M.
    Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy.
    Bierhorst, P.
    National Institute of Standards and Technology, Boulder, CO, USA.
    Burchardt, D.
    Ludwig-Maximilians-Universität, Munich, Germany.
    Cabello, A.
    Departamento de Física Aplicada II, Universidad de Sevilla, Seville, Spain.
    Cariñe, J.
    Millennium Institute for Research in Optics, Universidad de Concepción, Universidad de Concepción, Concepción, Chile.
    Carrasco, S.
    ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.
    Carvacho, G.
    Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy.
    Cavalcanti, D.
    Chaves, R.
    Cortés-Vega, J.
    Cuevas, A.
    Delgado, A.
    de Riedmatten, H.
    Eichler, C.
    Farrera, P.
    Fuenzalida, J.
    García-Matos, M.
    Garthoff, R.
    Gasparinetti, S.
    Gerrits, T.
    Ghafari Jouneghani, F.
    Glancy, S.
    Gómez, E. S.
    González, P.
    Guan, J. -Y.
    Handsteiner, J.
    Heinsoo, J.
    Heintze, G.
    Hirschmann, A.
    Jiménez, O.
    Kaiser, F.
    Knill, E.
    Knoll, L. T.
    Krinner, S.
    Kurpiers, P.
    Larotonda, M. A.
    Larsson, Jan-Åke
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska fakulteten.
    Lenhard, A.
    Li, H.
    Li, M. -H.
    Lima, G.
    Liu, B.
    Liu, Y.
    López Grande, I. H.
    Lunghi, T.
    Ma, X.
    Magaña-Loaiza, O. S.
    Magnard, P.
    Magnoni, A.
    Martí­-Prieto, M.
    Martínez, D.
    Mataloni, P.
    Mattar, A.
    Mazzera, M.
    Mirin, R. P.
    Mitchell, M. W.
    Nam, S.
    Oppliger, M.
    Pan, J. -W.
    Patel, R. B.
    Pryde, G. J.
    Rauch, D.
    Redeker, K.
    Rieländer, D.
    Ringbauer, M.
    Roberson, T.
    Rosenfeld, W.
    Salathé, Y.
    Santodonato, L.
    Sauder, G.
    Scheidl, T.
    Schmiegelow, C. T.
    Sciarrino, F.
    Seri, A.
    Shalm, L. K.
    Shi, S. -C
    Slussarenko, S.
    Stevens, M. J.
    Tanzilli, S.
    Toledo, F.
    Tura, J.
    Ursin, R.
    Vergyris, P.
    Verma, V. B.
    Walter, T.
    Wallraff, A.
    Wang, Z.
    Weinfurter, H.
    Weston, M. M.
    White, A. G.
    Wu, C.
    Xavier, Guilherme B.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska fakulteten.
    You, L.
    Yuan, X.
    Zeilinger, A.
    Zhang, Q.
    Zhang, W.
    Zhong, J.
    Challenging Local Realism with Human Choices2018Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 557, s. 212-216Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A Bell test is a randomized trial that compares experimental observations against the philosophical worldview of local realism , in which the properties of the physical world are independent of our observation of them and no signal travels faster than light. A Bell test requires spatially distributed entanglement, fast and high-efficiency detection and unpredictable measurement settings. Although technology can satisfy the first two of these requirements, the use of physical devices to choose settings in a Bell test involves making assumptions about the physics that one aims to test. Bell himself noted this weakness in using physical setting choices and argued that human 'free will' could be used rigorously to ensure unpredictability in Bell tests. Here we report a set of local-realism tests using human choices, which avoids assumptions about predictability in physics. We recruited about 100,000 human participants to play an online video game that incentivizes fast, sustained input of unpredictable selections and illustrates Bell-test methodology. The participants generated 97,347,490 binary choices, which were directed via a scalable web platform to 12 laboratories on five continents, where 13 experiments tested local realism using photons, single atoms, atomic ensembles and superconducting devices. Over a 12-hour period on 30 November 2016, participants worldwide provided a sustained data flow of over 1,000 bits per second to the experiments, which used different human-generated data to choose each measurement setting. The observed correlations strongly contradict local realism and other realistic positions in bi-partite and tri-partite 12 scenarios. Project outcomes include closing the 'freedom-of-choice loophole' (the possibility that the setting choices are influenced by 'hidden variables' to correlate with the particle properties), the utilization of video-game methods for rapid collection of human-generated randomness, and the use of networking techniques for global participation in experimental science.

  • 18.
    Aberger, Martin
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska högskolan.
    Effects of Nonlinearities in Black Box Identification of an Industrial Robot2000Rapport (Annet vitenskapelig)
    Abstract [en]

    This paper discusses effects of nonlinearities in black box identification of one axis of a robot. The used data come from a commercial ABB robot, IRB1400. A three-mass flexible model for the robot was built in MathModelica. The nonlinearities in the model are nonlinear friction and backlash in the gear box.

  • 19. Bestill onlineKjøp publikasjonen >>
    Abidin, Aysajan
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska högskolan.
    Authentication in Quantum Key Distribution: Security Proof and Universal Hash Functions2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Quantum Key Distribution (QKD) is a secret key agreement technique that consists of two parts: quantum transmission and measurement on a quantum channel, and classical post-processing on a public communication channel. It enjoys provable unconditional security provided that the public communication channel is immutable. Otherwise, QKD is vulnerable to a man-in-the-middle attack. Immutable public communication channels, however, do not exist in practice. So we need to use authentication that implements the properties of an immutable channel as well as possible. One scheme that serves this purpose well is the Wegman-Carter authentication (WCA), which is built upon Almost Strongly Universal2 (ASU2) hashing. This scheme uses a new key in each authentication attempt to select a hash function from an ASU2 family, which is then used to generate the authentication tag for a message.

    The main focus of this dissertation is on authentication in the context of QKD. We study ASU2 hash functions, security of QKD that employs a computationally secure authentication, and also security of authentication with a partially known key. Specifically, we study the following.

    First, Universal hash functions and their constructions are reviewed, and as well as a new construction of ASU2 hash functions is presented. Second, security of QKD that employs a specific computationally secure authentication is studied. We present detailed attacks on various practical implementations of QKD that employs this authentication. We also provide countermeasures and prove necessary and sufficient conditions for upgrading the security of the authentication to the level of unconditional security. Third, Universal hash function based multiple authentication is studied. This uses a fixed ASU2 hash function followed by one-time pad encryption, to keep the hash function secret. We show that the one-time pad is necessary in every round for the authentication to be unconditionally secure. Lastly, we study security of the WCA scheme, in the case of a partially known authentication key. Here we prove tight information-theoretic security bounds and also analyse security using witness indistinguishability as used in the Universal Composability framework.

    Delarbeid
    1. New Universal Hash Functions
    Åpne denne publikasjonen i ny fane eller vindu >>New Universal Hash Functions
    2012 (engelsk)Inngår i: Lecture Notes in Computer Science, Vol. 7242 / [ed] Frederik Armknecht and Stefan Lucks, Springer Berlin Heidelberg , 2012, s. 99-108Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Universal hash functions are important building blocks for unconditionally secure message authentication codes. In this paper, we present a new construction of a class of Almost Strongly Universal hash functions with much smaller description (or key) length than the Wegman-Carter construction. Unlike some other constructions, our new construction has a very short key length and a security parameter that is independent of the message length, which makes it suitable for authentication in practical applications such as Quantum Cryptography.

    sted, utgiver, år, opplag, sider
    Springer Berlin Heidelberg, 2012
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349 ; 7242
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-84711 (URN)10.1007/978-3-642-34159-5_7 (DOI)978-3-642-34158-8 (ISBN)978-3-642-34159-5 (ISBN)
    Konferanse
    4th Western European Workshop on Research in Cryptology, WEWoRC 2011, Weimar, Germany, July 20-22, 2011
    Prosjekter
    ICG QC
    Tilgjengelig fra: 2012-10-18 Laget: 2012-10-17 Sist oppdatert: 2018-01-31
    2. Vulnerability of "A Novel Protocol-Authentication Algorithm Ruling out a Man-in-the-Middle Attack in Quantum Cryptography"
    Åpne denne publikasjonen i ny fane eller vindu >>Vulnerability of "A Novel Protocol-Authentication Algorithm Ruling out a Man-in-the-Middle Attack in Quantum Cryptography"
    2009 (engelsk)Inngår i: International Journal of Quantum Information, ISSN 0219-7499, Vol. 7, nr 5, s. 1047-1052Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In this paper, we review and comment on "A novel protocol-authentication algorithm ruling out a man-in-the-middle attack in quantum cryptography" [M. Peev et al., Int. J. Quant. Inf. 3 (2005) 225]. In particular, we point out that the proposed primitive is not secure when used in a generic protocol, and needs additional authenticating properties of the surrounding quantum-cryptographic protocol.

    Emneord
    Quantum cryptography, quantum key distribution, authentication
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-20405 (URN)10.1142/S0219749909005754 (DOI)
    Prosjekter
    ICG QC
    Tilgjengelig fra: 2009-09-08 Laget: 2009-09-07 Sist oppdatert: 2019-08-15bibliografisk kontrollert
    3. Attacks on quantum key distribution protocols that employ non-ITS authentication
    Åpne denne publikasjonen i ny fane eller vindu >>Attacks on quantum key distribution protocols that employ non-ITS authentication
    Vise andre…
    2016 (engelsk)Inngår i: Quantum Information Processing, ISSN 1570-0755, E-ISSN 1573-1332, Vol. 15, nr 1, s. 327-362Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    We demonstrate how adversaries with unbounded computing resources can break Quantum Key Distribution (QKD) protocols which employ a particular message authentication code suggested previously. This authentication code, featuring low key consumption, is not Information-Theoretically Secure (ITS) since for each message the eavesdropper has intercepted she is able to send a different message from a set of messages that she can calculate by finding collisions of a cryptographic hash function. However, when this authentication code was introduced it was shown to prevent straightforward Man-In-The-Middle (MITM) attacks against QKD protocols.

    In this paper, we prove that the set of messages that collide with any given message under this authentication code contains with high probability a message that has small Hamming distance to any other given message. Based on this fact we present extended MITM attacks against different versions of BB84 QKD protocols using the addressed authentication code; for three protocols we describe every single action taken by the adversary. For all protocols the adversary can obtain complete knowledge of the key, and for most protocols her success probability in doing so approaches unity.

    Since the attacks work against all authentication methods which allow to calculate colliding messages, the underlying building blocks of the presented attacks expose the potential pitfalls arising as a consequence of non-ITS authentication in QKDpostprocessing. We propose countermeasures, increasing the eavesdroppers demand for computational power, and also prove necessary and sufficient conditions for upgrading the discussed authentication code to the ITS level.

    sted, utgiver, år, opplag, sider
    Springer Publishing Company, 2016
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-91260 (URN)10.1007/s11128-015-1160-4 (DOI)000372876800020 ()
    Prosjekter
    ICG QC
    Merknad

    Vid tiden för disputation förelåg publikationen som manuskript

    Funding agencies: Vienna Science and Technology Fund (WWTF) [ICT10-067]; Austrian Research Promotion Agency (FFG) [Bridge-2364544]

    Tilgjengelig fra: 2013-04-18 Laget: 2013-04-18 Sist oppdatert: 2019-08-15bibliografisk kontrollert
    4. On Security of Universal Hash Function Based Multiple Authentication
    Åpne denne publikasjonen i ny fane eller vindu >>On Security of Universal Hash Function Based Multiple Authentication
    2012 (engelsk)Inngår i: Lecture Notes in Computer Science, Vol. 7618 / [ed] Chim, Tat Wing and Yuen, Tsz Hon, 2012, s. 303-310Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Universal hash function based multiple authentication was originally proposed by Wegman and Carter in 1981. In this authentication, a series of messages are authenticated by first hashing each message by a fixed (almost) strongly universal$_2$ hash function and then encrypting the hash value with a preshared one-time pad. This authentication is unconditionally secure. In this paper, we show that the unconditional security cannot be guaranteed if the hash function output for the first message is not encrypted, as remarked in [Atici and Stinson, CRYPTO '96. LNCS, vol. 1109]. This means that it is not only sufficient, but also necessary, to encrypt the hash of every message to be authenticated in order to have unconditional security. The security loss is demonstrated by a simple existential forgery attack.

    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349 ; 7618
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-84732 (URN)10.1007/978-3-642-34129-8_27 (DOI)978-3-642-34128-1 (ISBN)978-3-642-34129-8 (ISBN)
    Konferanse
    14th International Conference on Information and Communications Security, ICICS 2012, Hong Kong, China, October 29-31, 2012
    Prosjekter
    ICG QC
    Tilgjengelig fra: 2012-10-18 Laget: 2012-10-18 Sist oppdatert: 2018-02-12
    5. Direct proof of security of Wegman-Carter authentication with partially known key
    Åpne denne publikasjonen i ny fane eller vindu >>Direct proof of security of Wegman-Carter authentication with partially known key
    2014 (engelsk)Inngår i: Quantum Information Processing, ISSN 1570-0755, E-ISSN 1573-1332, Vol. 13, nr 10, s. 2155-2170Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Information-theoretically secure (ITS) authentication is needed in Quantum Key Distribution (QKD). In this paper, we study security of an ITS authentication scheme proposed by Wegman& Carter, in the case of partially known authentication key. This scheme uses a new authentication key in each authentication attempt, to select a hash function from an Almost Strongly Universal2 hash function family. The partial knowledge of the attacker is measured as the trace distance between the authentication key distribution and the uniform distribution; this is the usual measure in QKD. We provide direct proofs of security of the scheme, when using partially known key, first in the information-theoretic setting and then in terms of witness indistinguishability as used in the Universal Composability (UC) framework. We find that if the authentication procedure has a failure probability ε and the authentication key has an ε´ trace distance to the uniform, then under ITS, the adversary’s success probability conditioned on an authentic message-tag pair is only bounded by ε +|Ƭ|ε´, where |Ƭ| is the size of the set of tags. Furthermore, the trace distance between the authentication key distribution and the uniform increases to |Ƭ|ε´ after having seen an authentic message-tag pair. Despite this, we are able to prove directly that the authenticated channel is indistinguishable from an (ideal) authentic channel (the desired functionality), except with probability less than ε + ε´. This proves that the scheme is (ε + ε´)-UC-secure, without using the composability theorem.

    sted, utgiver, år, opplag, sider
    Springer, 2014
    Emneord
    Authentication, Strongly Universal hash functions, Partially known key, Trace distance, Universal Composability, Quantum Key Distribution.
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-91264 (URN)10.1007/s11128-013-0641-6 (DOI)000341842000002 ()
    Prosjekter
    ICG QC
    Tilgjengelig fra: 2013-04-18 Laget: 2013-04-18 Sist oppdatert: 2017-12-06bibliografisk kontrollert
  • 20.
    Abidin, Aysajan
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    On Security of Universal Hash Function Based Multiple Authentication2012Inngår i: Lecture Notes in Computer Science, Vol. 7618 / [ed] Chim, Tat Wing and Yuen, Tsz Hon, 2012, s. 303-310Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Universal hash function based multiple authentication was originally proposed by Wegman and Carter in 1981. In this authentication, a series of messages are authenticated by first hashing each message by a fixed (almost) strongly universal$_2$ hash function and then encrypting the hash value with a preshared one-time pad. This authentication is unconditionally secure. In this paper, we show that the unconditional security cannot be guaranteed if the hash function output for the first message is not encrypted, as remarked in [Atici and Stinson, CRYPTO '96. LNCS, vol. 1109]. This means that it is not only sufficient, but also necessary, to encrypt the hash of every message to be authenticated in order to have unconditional security. The security loss is demonstrated by a simple existential forgery attack.

  • 21.
    Abidin, Aysajan
    et al.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska högskolan.
    Larsson, Jan-Åke
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska högskolan.
    Direct proof of security of Wegman-Carter authentication with partially known key2014Inngår i: Quantum Information Processing, ISSN 1570-0755, E-ISSN 1573-1332, Vol. 13, nr 10, s. 2155-2170Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Information-theoretically secure (ITS) authentication is needed in Quantum Key Distribution (QKD). In this paper, we study security of an ITS authentication scheme proposed by Wegman& Carter, in the case of partially known authentication key. This scheme uses a new authentication key in each authentication attempt, to select a hash function from an Almost Strongly Universal2 hash function family. The partial knowledge of the attacker is measured as the trace distance between the authentication key distribution and the uniform distribution; this is the usual measure in QKD. We provide direct proofs of security of the scheme, when using partially known key, first in the information-theoretic setting and then in terms of witness indistinguishability as used in the Universal Composability (UC) framework. We find that if the authentication procedure has a failure probability ε and the authentication key has an ε´ trace distance to the uniform, then under ITS, the adversary’s success probability conditioned on an authentic message-tag pair is only bounded by ε +|Ƭ|ε´, where |Ƭ| is the size of the set of tags. Furthermore, the trace distance between the authentication key distribution and the uniform increases to |Ƭ|ε´ after having seen an authentic message-tag pair. Despite this, we are able to prove directly that the authenticated channel is indistinguishable from an (ideal) authentic channel (the desired functionality), except with probability less than ε + ε´. This proves that the scheme is (ε + ε´)-UC-secure, without using the composability theorem.

  • 22.
    Abidin, Aysajan
    et al.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    Larsson, Jan-Åke
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    New Universal Hash Functions2012Inngår i: Lecture Notes in Computer Science, Vol. 7242 / [ed] Frederik Armknecht and Stefan Lucks, Springer Berlin Heidelberg , 2012, s. 99-108Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Universal hash functions are important building blocks for unconditionally secure message authentication codes. In this paper, we present a new construction of a class of Almost Strongly Universal hash functions with much smaller description (or key) length than the Wegman-Carter construction. Unlike some other constructions, our new construction has a very short key length and a security parameter that is independent of the message length, which makes it suitable for authentication in practical applications such as Quantum Cryptography.