We propose constant-round protocols for interval tests, equality tests, and comparisons where shared secret inputs are not given bitwise. In [9]. Damgård et al. presented a novel protocol called the bit-decomposition, which can convert a polynomial sharing of an element in prime field Zp into sharings of bits. Though, by using the bit-decomposition protocol, those protocols can be constructed with constant round complexities theoretically, it involves expensive computation, leading to relatively high round and communication complexities. In this paper, we construct more efficient protocols for those protocols without relying on the bit-decomposition protocol. In the interval test protocol, checking whether a shared secret exists in the known interval is reduced to checking whether a bitwise-shared random secret exists in the appropriate interval. In the comparison protocol, comparing two shared secrets is reduced to comparing the two secrets viaindirectly where p is an odd prime for an underlying linear secret sharing scheme. In the equality test protocol, checking whether two shared secrets are equal is reduced to checking whether the difference of the two secrets is zero and furthermore checking whether the difference is a zero is reduced to checking quadratice residuosity of a random secret in a probabilistic way.

For an integer d > 0, a d-queue layout of a graph consists of a total order of the vertices, and a partition of the edges into d sets of non-nested edges with respect to the vertex ordering. Recently V. Dujmovi and D. R. Wood showed that for every integer d ≥ 2, every graph G has a d-queue layout of a subdivision of G with 2logd qn(G)+1 division vertices per edge, where qn(G) is the queue number of G. This paper improves the result for the case of a bipartite graph, and shows that for every integer d ≥ 2, every bipartite graph Gm,n has a d-queue layout of a subdivision of Gm,n with logd n-1 division vertices per edge, where m and n are numbers of vertices of the partite sets of Gm,n (m ≥ n).

Copyright protection is a major issue in distributing content on Internet or broadcasting service. One well-known method of protecting copyright is a traitor tracing scheme. With this scheme, if a pirate decoder is made, the content provider can check the secret key contained in it and trace the authorized user/subscriber (traitor). Furthermore, users require that they could obtain services anywhere they want (Anywhere TV). For this purpose, they would need to take along their secret keys and therefore key exposure has to be kept in mind. As one of countermeasures against key exposure, a forward secure public key cryptosystem has been developed. In this system, the user secret key remains valid for a limited period of time. It means that even if it is exposed, the user would be affected only for the limited time period. In this paper, we propose a traitor tracing scheme secure against adaptive key exposure (TTaKE) which contains the properties of both a traitor tracing scheme and a forward secure public key cryptosystem. It is constructed by using two polynomials with two variables to generate user secret keys. Its security proof is constructed from scratch. Moreover we confirmed its efficiency through comparisons. Finally, we show the way how its building blocks can be applied to anywhere TV service. Its structure fits current broadcasting systems.

In this paper, we introduce a new decision problem associated with lattices, named the Exact Length Vector Problem (ELVP), and prove the NP-completeness of ELVP in the ∞ norm. Moreover, we define two variants of ELVP. The one is a binary variant of ELVP, named the Binary Exact Length Vector Problem (BELVP), and is shown to be NP-complete in any p norm (1 ≤ p ≤ ∞). The other is a nonnegative variant of ELVP, named the Nonnegative Exact Length Vector Problem (NELVP). NELVP is defined in the 1 norm, and is also shown to be NP-complete.

Buffer insertion plays a great role in modern global interconnect optimization. But too many buffers exhaust routing resources, and result in the rise of the power dissipation. Unfortunately, simplified delay models used by most of the present buffer insertion algorithms may introduce redundant buffers due to the delay estimation errors, whereas accurate delay models expand the solution space significantly, resulting in unacceptable runtime. Moreover, the power dissipation problem becomes a dominant factor in the state-of-the-art IC design. Not only transistor but also interconnect should be taken into consideration in the power calculation, which makes us have to use an accurate power model to calculate the total power dissipation. In this paper, we present two stochastic optimization methods, simulated annealing and solution space smoothing, which use accurate delay and power models to construct buffered routing trees with considerations of buffer/wire sizing, routing obstacles and delay and power optimization. Experimental results show our methods can save much of the buffer area and the power dissipation with better solutions, and for the cases with pins ≤ 15, the runtime of solution space smoothing is tens of times faster.

Vertical Power MOSFETs are widely designed by deep well structures for breakdown requirement. In this study, we proposed, simulated, and analyzed a "shallow dual well" structure Power MOSFET, which utilize an n-well to cover the conventional p-well. The cell pitch can be reduced and results in an increased cell density. The reduced cell pitch and increased cell density improves the gate charge and on resistance performances about 66.5% and 15.8% without sacrificing the device breakdown owing to a shallow junction design. In addition, with the dual well structure design, the breakdown point will occur at the center of the well. Therefore, the capability of avalanche energy can be improved about 1.9 times than the tradition well structure.

The proton-exchanged waveguide formed on MgO-doped lithium niobate crystals is resistant to the optical damage or the photorefractive effect. Therefore, this waveguide is believed to be a promising device for optical information and processing. However, the optical damage can also be an important problem for this waveguide in the communication wavelength since the high-power optical source is used. In this report, a brief general review on the optical properties and its practical application of the lithium niobate crystal as the optical waveguide are given. Then the experimental research work aimed to clarify the properties and its mechanism of the electrooptic effect and the optical damage or photorefractivity of the lithium niobate optical waveguide is described. In this work, the optical damage in this proton-exchanged waveguide is measured quantitatively at various optical wavelengths including blue and red light by using the holographic grating method and the infrared communication wavelength (1550 nm) by using the prism coupler method. The optical damage is significant not only in blue wavelength but also in the red, and even at 1550 nm with high power (100 mW) laser diode for communication. So the optical damage cannot be negligible also in the communication wavelengths. The effect of annealing temperature is also discussed. At the relatively high temperatures, the optical damages are founde to be annealed out. The effect of the applied electric field to the optical damage is experimentally discussed and its enhancement is observed to the applied d.c. and a.c. fields. In conclusion, the optical properties as the electrooptic constant and the optical damage are experimentally measured and the many fundamental data are obtained to realize the useful and practical optical devices.

A transport layer mobility management scheme for handling seamless handoffs between appropriate networks is presented. The future mobile environment will be characterized by multimodal connectivity with dynamic switching. Many technologies have been proposed to support host mobility across diverse wireless networks, and operate in various layers of the network architecture. Our major focus is on the transport protocol that recovers packets lost during handoffs and controls transmission speed to achieve efficient communication. Majority of the existing technologies can maintain the connection by updating the information of a single connection around a handoff. Moreover, none of the studies extensively examine the handoff latencies and focus how an appropriate network is selected, during the handoff. In this paper, we first extensively investigate the various handoff latencies and discuss the limited performance of existing technologies based on the single connection. We then propose a new scheme resolving the problems by the transport protocol enabling the adaptive selection of an appropriate interface based on communication condition among all available interfaces. Finally, we demonstrate that the proposed scheme promptly and reliably selects the appropriate interface, and achieves excellent goodput performance by comparing with the existing technologies.

Light-induced self-written (LISW) technology is a unique and simple method of forming low-loss 3-dimensional (3-D) optical circuits in photopolymers using radiation from an optical fiber. Since this technology is applicable to almost all kinds of optical fiber and optical wiring, many studies have been carried in a number of different organizations on the applications of this technology. The technology helps simplify optical interconnections, and it is expected that it will reduce the cost of mounting optical devices. In this paper, we introduce LISW technology and report on related studies developed in our research group.

A precoding scheme is described for multiple-input and multiple-output orthogonal frequency-division multiplexing systems with a QR-decomposition maximum likelihood detector (MLD) incorporated with a parallel interference canceller (PIC) at a receiver. Transmit antenna ranking based on received substream signal power or per-substream minimum Euclidean distances is fed back to a transmitter. Based on the ranking information, precoding matrices are determined as permutation matrices such that specific packets are transmitted from transmit antennas with higher channel quality over the whole subcarriers. The simulation results demonstrated that precoding effectively utilizes PIC by reducing the possibility that all substreams are incorrectly decoded and thus improves the transmission performance of a QR-decomposition MLD with PIC.

This paper describes a novel parameter generation algorithm for an HMM-based speech synthesis technique. The conventional algorithm generates a parameter trajectory of static features that maximizes the likelihood of a given HMM for the parameter sequence consisting of the static and dynamic features under an explicit constraint between those two features. The generated trajectory is often excessively smoothed due to the statistical processing. Using the over-smoothed speech parameters usually causes muffled sounds. In order to alleviate the over-smoothing effect, we propose a generation algorithm considering not only the HMM likelihood maximized in the conventional algorithm but also a likelihood for a global variance (GV) of the generated trajectory. The latter likelihood works as a penalty for the over-smoothing, i.e., a reduction of the GV of the generated trajectory. The result of a perceptual evaluation demonstrates that the proposed algorithm causes considerably large improvements in the naturalness of synthetic speech.

In this paper, we propose an adaptive data transmission scheme for DS/CDMA packet radio communication systems in bandlimited indoor multipath fading channels. We first analyze the relationship between the code rate and the processing gain (defined as the number of chips per coded bit) in maximizing the normalized throughput in connection with the channel state of the indoor multipath fading channels. One observation made is that the maximum throughput with BPSK modulation is attained when the code rate is chosen as low as possible irrespective of the channel state, and the processing gain is increased (decreased) as the channel becomes worse (better). The other observation made is that when DPSK modulation is employed, there exists an optimal combination of the code rate and the processing gain in maximizing the normalized throughput for each channel state. Based on these observations, we propose to adapt the processing gain and/or code rate according to the fading conditions in order to maximize the normalized throughput. We analyze the performance of the proposed scheme and compare it with the non-adaptive data transmission scheme. Our results show that the adaptive transmission scheme yields a significant performance improvement over the nonadaptive scheme, and increasing the adaptation level is more effective as the channel gets worse, but the 3-state adaptation seems to be practically optimum.

The most time consuming operation to verify a signature with the Elliptic Curve Digital Signature Algorithm is a multi-scalar multiplication with two scalars. Efficient methods for its computation are the Shamir method and the Interleave method, whereas the performance of those methods can be improved by using general base-2 representations of the scalars. In exchange for the speed-up, those representations require the precomputation of several points that must be stored. In the case of two precomputed points, the Interleave method and the Shamir method provide the same, optimal efficiency. In the case of more precomputed points, only the Interleave method can be sped-up in an optimal way and is currently more efficient than the Shamir method. This paper proposes a new general base-2 representation of the scalars that can be used to speed up the Shamir method. It requires the precomputation of ten points and is more efficient than any other representation that also requires ten precomputed points. Therefore, the proposed method is the first to improve the Shamir method such that it is faster than the Interleave method.

This paper proposes an event-based transition system called A-LTS. An A-LTS is a simple system consisting of two agents, a basic program and a monitor. The monitor observes the behavior of the basic program and if the behavior matches some pre-defined pattern, then the monitor interrupts the execution of the basic program and possibly triggers the execution of another specific program. An A-LTS models a common feature found in recent software technologies such as Aspect-Oriented Programming (AOP), history-based access control and active database. We investigate the expressive power of A-LTS and show that it is strictly stronger than finite state machines and strictly weaker than pushdown automata (PDA). This implies that the model checking problem for A-LTS is decidable. It is also shown that the expressive power of A-LTS, linear context-free grammar and deterministic PDA are mutually incomparable. We also discuss the relationship between A-LTS and pointcut/advice in AOP.

In this letter, we propose a novel subsampling based image watermark sequentially embedding scheme to reduce the risk of common permutation attack. The image is still perceptual after watermarking, and experimental results also show its effectiveness and robustness.

A new block coded modulation scheme with inter-level memory is proposed. The proposed code construction is based on the use of single parity check codes to concatenate a set of coded blocks. Simulation results show that the proposed scheme can achieve considerable coding gains while the decoding complexity is not too large.

This report presents Dual Field-modulating-Plates (Dual-FP) technology for a 28 V operated high power GaAs heterojunction FET (HJFET) amplifier. A developed HJFET has two FP electrodes; the 1st-FP is connected to the gate and the 2nd-FP to the ground. The 2nd-FP suppresses the drain current dispersion effectively cooperating with the 1st-FP, and it can also reduce the gate-drain parasitic capacitance. The developed push-pull amplifier, with four Dual-FPFET chips, demonstrated 55.1 dBm (320 W) output power with a 14.0 dB linear gain and a drain efficiency of 62% at 2.14 GHz. Under two-carrier W-CDMA signals, it showed a high drain efficiency of 30% and low third-order Inter-modulation distortion of -37 dBc at output power of 47.5 dBm.

We investigate the issues involved in designing a packet scheduler for the proportional delay differentiation (PDD) model in differentiated services (DiffServ) networks. The PDD model controls the average waiting time of each class such that the average waiting time is proportional to its corresponding delay differentiation parameter. This paper proposes a novel packet scheduler for PDD referred to as the longest waiting time first (LWTF). By adding certain conditions, we found that the LWTF scheduler can be reduced to a known packet scheduler-priority queue with linear priorities (PQ-LP). The properties and behaviors of LWTF can be predicted from the analysis of PQ-LP. The simulation results in comparison with other PDD algorithms have also revealed that LWTF provides no worse level of service quality in long timescales and affords more accurate and robust control over the delay ratio in short timescales.

Two-dimensional discrete wavelet transform (DWT) for processing image is conventionally designed by line-based architectures, which are simple and have low complexity. However, they suffer from two main shortcomings - the memory required for storing intermediate data and the long latency of computing wavelet coefficients. This work presents a new block-based architecture for computing lifting-based 2-D DWT coefficients. This architecture yields a significantly lower buffer size. Additionally, the latency is reduced from N2 down to 3N as compared to the line-based architectures. The proposed architecture supports the JPEG2000 default filters and has been realized in ARM-based ALTERA EPXA10 Development Board at a frequency of 44.33 MHz.

Accurate extraction of the trap position in the oxide in deep-submicron MOSFET by RTN measurement has been investigated both theoretically and experimentally. The conventional equation based on the ratio of emission time and capture time ignores two effects, that is, the poly gate depletion effect and surface potential variation in strong inversion regime. In this paper, by including both of the two effects, we have derived a new equation which gives us more accurate information of the trap depth from the interface and the trap energy. With experimental result, we compare the trap depth obtained from the new equation and that of the conventional method.