The new concept of ES (Encryption-Signature) schemes which realize an encryption scheme and a signature scheme with a unique padding technique and key pair, was proposed by Coron et al. They also gave a proof of PSS-ES. In this paper, first, we discuss the methodology for the construction for ES schemes by using padding techniques of encryption schemes, and propose a new ES scheme, OAEP-ES, adopting this methodology. It is proven that OAEP-ES scheme can be constructed under the assumption of the one-wayness of the encryption permutation, while the security of PSS-ES utilized as an encryption scheme is based on the partial-domain one-wayness; which is a theoretical progress since the one-wayness is more general assumption than the partial-domain one-wayness. It is shown that OAEP-ES attains tighter security than PSS-ES, which is a practical interest.

Secure distribution of digital goods is now a significantly important issue for protecting publishers' copyrights. In this paper, we study a useful primitive for constructing a secure and efficient digital rights management system (DRM) where a server which encrypts digital content and one which issues the corresponding decryption key works independently, and existing schemes lack this property. We first argue the desired property necessary of an encryption scheme for constructing an efficient DRM, and formally define an encryption scheme as split encryption scheme containing such property. Also, we show that an efficient split encryption scheme can be constructed from any identity-based scheme. More precisely, we show an equivalence result implying that a split encryption scheme for some system parameter setting and an identity-based encryption scheme have the same primitives but for different uses. Since currently there is no identity-based encryption scheme which is based on well-known computational assumption and/or provably secure in the standard model (i.e. without the random oracle model), by reasonably tuning the system parameter, we show another construction of split encryption which is secure against chosen ciphertext attacks in the standard model assuming that decision Diffie-Hellman problem is hard to solve.

A new approach for electronic sealed-bid auctions that preserve the privacy of losing bids is presented. It reduces the number of operations performed by the auctioneers to O(log ); previous protocols require O(N ) or O(N log ) where the number of bidders is N and that of available bidding prices is . Namely, the number of auctioneers' operations in our auction protocol is independent of the number of bidders. This feature offers strong advantages in massive auctions. We also propose a new scheme that checks the equality of two values without disclosing them. The scheme enhances our basic auction protocol, in terms of security and communication costs.

There are two main types of digital watermark systems. In the first, users are given their own detection programs by which to verify the presence of watermark in data they have in their possession. In the second, users must request such verification from a detection center. The disadvantage of the first type is the possibility that a user might be able to analyze the detection program sufficiently to be able to obtain the secret data (secret key) used to embed the watermark. The disadvantage of the second is the possibility that a center might give dishonest results. In this paper, we propose a watermark detection scheme that can be used to overcome the disadvantages of both: it prevents users from obtaining secret key, and it prevents a center from reporting dishonest results. Our scheme is based on a previously proposed scheme which nearly achieved the same goals but, unfortunately, allowed users to receive watermark detection results for data specially created by them so as to reveal, through the results, secret information about how a center created its watermarks. To overcome this drawback, we have developed new scheme by which a center can prove its detection results to a user without revealing any other information. This scheme was developed by extending the work found in. Moreover we provide an option that prevents the center from encroaching on a user's privacy. The resulting watermark detection scheme is the first that, in addition to protecting secret keys of watermarks from user-tampering, is also able to prevent a center from reporting dishonest results. Although the proposed scheme is introduced first using the patch-work watermarking system, it is straightforward to extend it to a scheme that uses the correlation-based watermarking system, which yields a more robust watermark detection scheme.

In this paper, a process is described for analysing the motion of a human target in a video stream. Moving targets are detected and their boundaries extracted. From these, a "star" skeleton is produced. Two motion cues are determined from this skeletonization: body posture, and cyclic motion of skeleton segments. These cues are used to determine human activities such as walking or running, and even potentially, the target's gait. Unlike other methods, this does not require an a priori human model, or a large number of "pixels on target". Furthermore, it is computationally inexpensive, and thus ideal for real-world video applications such as outdoor video surveillance.

We propose a new method to precisely detect pupil contours in face images. Pupil contour detection is necessary for various applications using face images. It is, however, difficult to detect pupils precisely because of their weak edges or lack of edges. The proposed method is based on minimizing the energy of pattern and edge. The basic idea of this method is that the energy, which consists of the pattern and the edge energy, has to be minimized. An efficient search method is also introduced to overcome the underlying problem of efficiency in energy minimization methods. "Guide patterns" are introduced for this purpose. Moreover, to detect pupils more precisely we use an ellipse model as pupil shape in this paper. Experimental results show the effectiveness of the proposed method.

Synchronous Gaussian code-division multiple access (CDMA) systems employing group-orthogonal signature waveforms are proposed and analyzed. All users in the system are divided into groups of users. The signature waveforms are constructed such that all the signature waveforms in one group are orthogonal to all the signature waveforms used in all other groups. This construction of signature waveforms ensures that there is no inter-group interference (i.e., among users in different groups), but at the expense of having intra-group interference (i.e., among users in the same group). However, by choosing a small size for each group, the intra-group interference can be effectively handled by a low-complexity, optimal (or suboptimal) multiuser detector. It is shown that a significant improvement in the system capacity can be achieved by the proposed technique over the conventional one that uses signature waveforms constructed from Welch-bound-equality (WBE) sequences. In particular, it is demonstrated that, while the conventional system's error performance is very sensitive to even small amount of overload, the proposed system with an appropriate design of signature waveforms can achieve a much higher overload (up to 300% as shown in the paper) with an excellent error performance.

A new bipolar scan waveform is proposed to increase the light emission duty factor by achieving the fast address in AC plasma display panel (AC-PDP). The new bipolar scan waveform consists of two-step scan pulse, which can separate the address discharge mode into two different discharge modes: a space charge generation mode and a wall charge accumulation mode. By adopting the new bipolar scan waveform, the light emission duty factor is increased considerably under the single scan ADS driving scheme due to the reduction of address time per single subfield.

This paper describes the performance improvement of power amplifiers by defected ground structure (DGS). Due to the excellent capability of harmonic rejection and tuning, DGS plays a great role in improving the major nonlinear behaviors of power amplifier such as output power, harmonics, power added efficiency (PAE), and the ratio between the carrier and the third order intermodulation distortion (C/IMD3). In order to verify the improvement of performances by DGS, measured data for a power amplifier, which adopts a 30 Watts LDMOS device for the operation at 2.1-2.2 GHz, are illustrated under several operating bias currents for two cases, i.e., with and without DGS attached. The principle of the improvement is described by the simple Volterra nonlinear transfer functions with the consideration of different operating classes. The obtained improvement of the 30 Watts power amplifier, under 400 mA of IdsQ as an example, includes the reduction in the second and third harmonics by 17 dB and 20 dB, and the increase in output power, PAE, and C/IMD3 by 1.3 Watts, 3.4%, and 4.7 dB, respectively.

This paper deals with a first evaluation of the efficiency and the robustness of the real-time "v-disparity" algorithm in stereovision for generic road obstacles detection towards various types of obstacles (vehicle, pedestrian, motorbike, cyclist, boxes) and under adverse conditions (day, night, rain, glowing effect, noise and false matches in the disparity map). The theoretical good properties of the "v-disparity" algorithm--accuracy, robustness, computational speed--are experimentally confirmed. The good results obtained allow us to use this stereo algorithm as the onboard perception process for Driving Safety Assistance: conductor warning and longitudinal control of a low speed automated vehicle (using a second order sliding mode control) in difficult and original situations, at frame rate using no special hardware. Results of experiments--Vehicle following at low speed, Stop'n'Go, Stop on Obstacle (pedestrian, fallen motorbike, load dropping obstacle)--are presented.

In this paper, a novel methodology for designing and analyzing high performance sigma-delta leapfrog modulators for ultra-high resolution analog-to-digital (A/D) converters is presented. The less sensitive topology, the leapfrog topology, in component variations is analyzed by considering the noise transfer function (NTF). By using theoretical analysis, the loop coefficients are constrained to a small, clear and definite range called the stable region (SR). With the output voltage limited within 2 V, an absolutely stable region (ASR) is obtained. A program that analyzes and generates the required coefficients is constructed for easily designing this topology. For a 256 over-sampling ratio (OSR) and the coefficients from ASR, the signal to noise ratio (SNR) and dynamic range (DR) are 105 dB and 100 dB, respectively. In accordance with the behavior simulation results, the system is not only stable and efficient but also suitable for high-resolution applications.

An analysis of the phase difference spectrum between two images allows precise image shift detection. Image shifts are directly evaluated from the phase difference spectrum without Fourier inversion. In the calculation, the weight function containing the frequency and the cross spectrum is used and an unlapping procedure is carried out. In an experiment using synthetic and real images of typical image patterns, accuracy as high as 0.01-0.02 pixel was achieved stably and reliably for most of the image patterns.

In the past decade, significant effort has been made toward increasing the accuracy and robustness of three-dimensional scanning methods. In this paper, we present a new prototype vision system named 3D Model Studio, which has been built to reconstruct a complete 3D model in as less as a few minutes. New schemes for a probe calibration and a 3D data merging (axis consolidation) are employed. We also propose a new semi-automatic contour registration method to generate accurate contour model from 3D data points, along with a contour triangulation based surface reconstruction. Experimental result shows that our system works well for reconstructing a complete 3D surface model of a human body.

This paper proposes a new concept of Interaction key. An interaction key is a group public key that corresponds to a shared key shared by multiple users, and it has a new feature that an interaction key generator can verify the following: the shared key has been generated now, and the shared key has not existed before. In other words, the multiple users can prove them to the key generator. This feature is different from Time-stamp technology proves that a message existed at a point in time. Here, the key generator is a third party that can observe communications of the multiple users. Present technology only allows a group member or a privileged entity to generate a group public key. We are not presently aware of a technology where a third party can generate the group public key as above. The interaction key technology is useful both for generating public key certificates and for message certification. In a certificate generation, a certificate authority can issue a public key certificate with the shared key (i.e. secret key) to be used by the multiple users. In a message certification, the users can prove the signed message has not existed before, since the message is signed by the shared key corresponds to the interaction key.

Kernel methods such as the support vector machines map input vectors into a high-dimensional feature space and linearly separate them there. The dimensionality of the feature space depends on a kernel function and is sometimes of an infinite dimension. The Gauss kernel is such an example. We discuss the effective dimension of the feature space with the Gauss kernel and show that it can be approximated to a sum of polynomial kernels and that its dimensionality is determined by the boundedness of the input space by considering the Taylor expansion of the kernel Gram matrix.

In this paper, we propose a new method of automatic speech summarization for each utterance, where a set of words that maximizes a summarization score is extracted from automatic speech transcriptions. The summarization score indicates the appropriateness of summarized sentences. This extraction is achieved by using a dynamic programming technique according to a target summarization ratio. This ratio is the number of characters/words in the summarized sentence divided by the number of characters/words in the original sentence. The extracted set of words is then connected to build a summarized sentence. The summarization score consists of a word significance measure, linguistic likelihood, and a confidence measure. This paper also proposes a new method of measuring summarization accuracy based on a word network expressing manual summarization results. The summarization accuracy of each automatic summarization is calculated by comparing it with the most similar word string in the network. Japanese broadcast-news speech, transcribed using a large-vocabulary continuous-speech recognition (LVCSR) system, is summarized and evaluated using our proposed method with 20, 40, 60, 70 and 80% summarization ratios. Experimental results reveal that the proposed method can effectively extract relatively important information by removing redundant or irrelevant information.

Determining consistent global checkpoints of a distributed computation has applications in the areas such as rollback recovery, distributed debugging, output commit and others. Netzer and Xu introduced the notion of zigzag paths and presented necessary and sufficient conditions for a set of checkpoints to be part of a consistent global checkpoint. This result also reveals that determining the existence of zigzag paths between checkpoints is crucial for determining consistent global checkpoints. Recent research also reveals that determining zigzag paths on-line is not possible. In this paper, we present an off-line method for determining the existence of zigzag paths between checkpoints.

Distributed database systems require a commit process to preserve the ACID property of transactions executed on a number of system sites. With the appearance of main memory database system, the database processing time has been reduced in the order of magnitude, since the database access does not incur any disk access at all. However, when it comes to distributed main memory database systems, the distributed commit process is still very slow since the disk logging at several sites has to precede the transaction commit. In this paper, we re-evaluate various distributed commit protocols and come up with a causal commit protocol suitable for distributed main memory database systems. To evaluate the performance of the proposed commit protocol, extensive simulation study has been performed. The simulation results confirm that the new protocol greatly reduces the time to commit the distributed transactions without any consistency problem.

The present paper reports a robust projection onto eigenspace that is based on iterative projection. The fundamental method proposed in Shakunaga and Sakaue and involves iterative analysis of relative residual and projection. The present paper refines the projection method by solving linear equations while taking noise ratio into account. The refinement improves both the efficiency and robustness of the projection. Experimental results indicate that the proposed method works well for various kinds of noise, including shadows, reflections and occlusions. The proposed method can be applied to a wide variety of computer vision problems, which include object/face recognition and image-based rendering.

We propose using SQP (Sequential Quadratic Programming) to directly recover 3D quadratic surface parameters from multiple views. A surface equation is used as a constraint. In addition to the sum of squared reprojection errors defined in the traditional bundle adjustment, a Lagrangian term is added to force recovered points to satisfy the constraint. The minimization is realized by SQP. Our algorithm has three advantages. First, given corresponding features in multiple views, the SQP implementation can directly recover the quadratic surface parameters optimally instead of a collection of isolated 3D points coordinates. Second, the specified constraints are strictly satisfied and the camera parameters and 3D coordinates of points can be determined more accurately than that by unconstrained methods. Third, the recovered quadratic surface model can be represented by a much smaller number of parameters instead of point clouds and triangular patches. Experiments with both synthetic and real images show the power of this approach.