Considering the edge-cloud environment and uploading large amounts of data from IoT devices through the edge node towards the cloud, this paper investigates an aggregation method of data streams compressed by Generalized Deduplication (GD) for the edge node. The simplest way is to decode GDcompressed data streams, aggregate raw streams and re-encode it into a single GD-compression stream. However, this involves a large computational complexity for aggregation due to the decoding and re-encoding of linear codes underlain the GD. From this observation, this paper presented a novel aggregation method, called Aggregable GD (AGD). The AGD is designed to aggregate multiple GD streams into a single AGD stream, and removes duplicated information among GD streams without decoding and re-encoding operations of GD. This paper also shows that AGD involves smaller computational complexity for data aggregation than the ordinary simple scheme. Furthermore, by the preliminary computer simulation using the Hamming code as the underlying linear code of GD, we demonstrate that AGD performs comparable to the ordinary method from the viewpoints of the compression rate.

Private information delivery (PID) from coded stor-age is a problem in delivering a message to a receiver without revealing the locations of servers storing encoded pieces of the message. Although existing researches only focus on the method to keep the server locations secret to the receiver, they do not consider other types of security against storage servers; security of stored messages against the Byzantine servers and the eavesdropping servers. In this paper, we first define the security properties against these attackers in PID; 1) the t-Byzantine resistance and 2) the$\mu$-message confidentiality, where$t$and$\mu$are the maximum capable numbers of Byzantine servers and eavesdropping servers, respectively. We also introduce an explicit scheme guaranteeing these properties with no deterioration of the PID's server locations privacy. The scheme can be viewed as a pre-coding method of messages using the maximum rank distance (MRD) code, and it can be applied to any PID scheme from coded storage. Furthermore, we characterize the maximum possible$t$and$\mu$in terms of parameters of the underlying MRD code, and clarify the degradation in the transmission rate introduced by these properties.

The traditional Domain Name System (DNS) lacks fundamental security and privacy features in its design. As privacy concerns increased on the Internet, security and privacy enhancements of DNS have been actively investigated. Specifically, in the context of user privacy in DNS queries, several relay-based anonymization schemes have been recently introduced. However, these schemes are vulnerable to collusion between relays and full-service resolvers, which means user identities cannot be hidden from resolvers. This paper introduces a new concept for achieving user anonymity in DNS queries through a multiple-relay-based approach, called μODNS (Mutualized Oblivious DNS), by extending the concept of existing relay-based schemes. μODNS introduces a reasonable assumption that each user has at least one trusted or dedicated relay within the network and mutually shares the relay with other users. The user simply sets his trusted relay as the next-hop relay to convey his queries to the resolver and randomly chooses its zero or more subsequent relays shared by other entities. Under this assumption, the user’s identity remains concealed from the target resolver in μODNS even if an unknown subset of relays colludes with the resolver. Namely, in μODNS, users can preserve their anonymity by paying a small cost of sharing their resources. Additionally, we extend existing protocols, Anonymized DNSCrypt and Oblivious DoH, to provide practical Proof-of-Concept specifications and implementations as instances of μODNS. These implementations are publicly available on the Internet as open-source software and public services. Furthermore, we demonstrate, through measurements of round-trip times for DNS messages, that our implementation can minimize the performance degradation resulting from its privacy enhancements, achieving performance levels that maintain the positive user experiences observed in existing schemes.

In 2010, JST/RISTEX in Japan started a new R&D program “Service Science, Solutions and Foundation Integrated Research Program”. The authors are engaged in a research project “Innovation for Service Space Communication by Voice Tweets in Nursing and Caring” selected by this program, and are developing a stress-free information assisting system based on smart voice messaging. By providing voice messaging environment optimized for current situation of nurses, the system helps nurses in their cooperation, knowledge sharing, and making work records, and as a result the system reduces various kinds of stresses associated with their work. To estimate the current situation of nurses, it is important to have detailed process models that describe working schedules and how they behave in various situations. Moreover, computer simulation based on the process models is useful for quantitative evaluation of the system. In this paper, we first analyze complex processes in nursing and caregiving services, and then propose a modeling architecture. An implementation based on object-oriented Petri nets is also presented.

A key issue for an organization that is responsible for disaster and emergency management becomes how to gather reliable and useful information during a major disaster. We consider an information-gathering platform for large-scale disasters and emergencies based on mobile terminals. A simple solution to realize an information-gathering system is to construct a server where information is uploaded and published. However, such a centralized approach is not flexible nor is it robust. For example, it is very hard to find an appropriate system to which the user can upload information during a disaster, and the centralized server may be down because of overload or has been physically destroyed. We must consider a distributed and dynamic architecture for the system. Security and privacy issues are another concern that should be addressed for providing information from user's mobile terminals. We focus on a design of a privacy preserving data upload mechanism for the information-gathering system. We design the mechanism that accommodates privacy requirements and present a feasibility analysis of the mechanism.

A challenging task in privacy protection for public data is to realize an algorithm that generalizes a table according to requirements of a data user. In this paper, we propose an anonymization scheme for generating a k-anonymous and l-diverse table, and show evaluation results using three different tables. Our scheme is based on both top-down and bottom-up approaches for full-domain and partial-domain generalization, and the requirements are automatically incorporated into the generated table. The generated table meets user's requirements and can be employed in the services provided by users without any modification or evaluation.

When a cellular phone is lost or stolen, it may be used improperly or the personal information may be stolen from it by a malicious user. Biometric authentication such as palm-print recognition is the strongest of the personal authentication technologies designed to prevent such misuse. Ito et al. proposed several palmprint recognition schemes using correspondence matching based on the phase-only correlation among various schemes. However, these schemes require a palmprint image to be captured with the hand touching the dedicated device, while palmprint images must be captured without such physical contact when using cellular phones. Thus these schemes cannot be applied to cellular phones since there are large positioning gaps and large differences in brightness and distortion between the images. Furthermore, they are not implemented in the cellular phone and their performances are not evaluated either.

Various handover technologies for heterogeneous wireless networks have been proposed. Most of these technologies are based on mobile IP technology, which reduces the processing time of handovers, network authentication, and service authentication. However, guaranteeing continuity with real-time services and/or video-on-demand services is difficult, particularly when the processing time is reduced by separating the node and network sides. Cooperative processing is therefore needed between the node and network sides or network and service authentication. Moreover, the handover mechanism must provide anonymity to the users of content distribution services. We propose an anonymous handover mechanism and efficient authentication scheme that divides the content key into two data sets and transmits these data sets to the mobile node by way of two paths. We analyze this handover mechanism in this paper.

In this paper, we propose a perfectly anonymous attribute authentication scheme that is both unidentifiable and untraceable. The proposed scheme employs a self-blindable certificate that a user is able to change randomly; thus the certificate is modified for each authentication, and the authentication scheme is unidentifiable and untraceable. Furthermore, our scheme can revoke issued self-blindable certificates without leaks of confidential private information and check the revocation status without online access.

Copyright protection is a major issue in online content distribution services and many key-management schemes have been proposed for protecting content. Tree-based schemes aim at reducing the load on the server, and do not give consideration to that on clients. This scheme is not fully suitable for devices with low computational capacity. On the other hand, the load on clients is low in a star-based scheme. However, the load on the server becomes large in proportion to the number of clients. This structure is far from scalable. We propose a key-management scheme that is the intermediate scheme of a star-based scheme and a tree-based scheme. Then, we evaluate both the load on the server and clients in key-management scheme using the three structures. We find that the load on server and that on clients in our scheme have a relation of trade-off. We can construct optimal key-management structure satisfying system requirements using our scheme. Furthermore, the loads on both the server and clients in our scheme are lower than tree-based structure scheme under a certain condition.

This paper describes the construction and performance evaluation of a mobile video communication system composed of an H.263 video encoder, decoder, and RF transceiver equipment. It can establish a video connection using a 32 kbits/s wireless channel because it uses automatic repeat request (ARQ) as the error control scheme. Retransmission control can produce excessive transmission delay, but the improved ARQ protocol and coding-rate control scheme adopted by this system minimizes the delay. This ARQ protocol uses short ARQ frame length and an acknowledgement/negative acknowledgement (ACK/NAK) indicator. The coding-rate control scheme uses backward NAK signals to reduce the coding rate of the video encoder as necessary. We measure the transmission delay characteristics of this video system and confirm that the proposed scheme can reduce the delay over a noisy channel. Subjective assessment tests involving videophone usage are also conducted. Test results show that in a noisy channel (BER=3/spl times/10/sup -3/), this system can achieve the same mean opinion store as in a noiseless channel.

This paper presents several interesting technologies that will support the next-generation of mobile wireless communications. First, a higher data transmission system based on the Personal Handy-Phone System (PHS) is introduced which provides 64 and 128 kb/s data services. Multi-slot channel assignment, which decreases blocking probability, is also presented. New wireless access, called PHS-ODS, is proposed. This can adaptively determine whether a received signal is voice or data, and forward the signal to the user's voice or data terminal as appropriate. A wireless agent that combines the conventional mobile agent with information specific to the mobile terminal environment is discussed. Furthermore, the application of AO/DI (always on dynamic ISDN) to wireless system is discussed; its concept and simulated effective data transmission speed are described.

We evaluate error control techniques proposed for a mobile video communication system. Our proposed system is based on SR-ARQ, using proposed ARQ protocol and coding control scheme for decreasing delay. Moreover, we assume the use of RCPC codes in realizing a hybrid ARQ scheme. We measure video quality degradation due to channel error and quantization error and also evaluate the maximum delay caused by interleaving and ARQ retransmission in Rayleigh and Rician fading channels. We show that the hybrid ARQ scheme is effective especially in Rican fading channels for reducing the delay.

Adaptive time diversity for CBR transmission in a time division duplex (TDD) system is proposed and its BER performance and video transmission performance are evaluated in PHS radio environments. In a TDD system, the frame error in the forward channel can be predicted from the frame error in the backward channel with high probability. We revealed that the proposed scheme shows a better BER performance than the RCPC code with practical interleaving in a Rayleigh fading environment. The proposed scheme improved the image SNR.

This paper proposes a new image transmission control method for fading channels, which uses SR-ARQ based on the DCT frequency and image frame structure. The experimental results gained using a PHS 32 kbit/s digital bearer as the communication channel show that, with some slight image quality degradation, this method can reduce the image transmission time by more 50% at a FER of 2/spl times/10/sup -1/ compared to conventional SR-ARQ. The experimental results gained by applying the proposed method to moving picture transmission using motion JPEG, show that a QCIF size moving picture can be transmitted at a frame rate of 1.3 frame/sec with some error, and is transmitted at a frame rate of 0.9 frame/sec at a FER of 2/spl times/10/sup -1/ with 1.5 dB of image quality degradation.

The Personal Handy Phone System (PHS) employs autonomous distributed control and a dynamic channel allocation scheme. A base station does not have many traffic channels because its cell radius is only a few hundred meters. However, a base station can experience heavy traffic. In this case, the blocking probability will increase. Congestion control can be employed, but it can never solve this problem fundamentally. We propose a dynamic cell assignment scheme and evaluate the improvement in system performance by computer simulations and theoretically. The scheme overlaps the base stations in and adjacent to heavy traffic areas to equalize base station loading. Each base station broadcasts a congestion factor and each mobile station dynamically selects a base station to get a traffic channel. This dynamic cell assignment technique makes it possible to improve the blocking probability characteristics.

The authors have analyzed the dynamics of associative neural networks based on macroscopic state equations and have shown that both a layered associative net and an autocorrelation type net have the same convergence property: If a recalling process succeeds, the network converges very fast to one of the memorized patterns. But if a recalling process fails, it converges very slowly to a spurious state or does not converge. This property was also checked by computer simulations on a large scale (N = 1000) neural network. Moreover, it is shown that the convergence time for a successful recall is of order log(N). If this convergence time difference is used, execution time and memory can be saved and it can be determined whether a recalling process succeeds or fails without any additional procedure.

Results are presented of a study of the feasibility realizing a real-time information retrieval service operating between different worldwide videotex systems by means of gateway facilities that use conversion of data syntax and processing of the videotex information structure. Two separate evaluations were carried out, both using response time as the performance criterion. One was for communication processes at both of two gateways, and the other was for data syntax conversion at the local host. Both approaches are considered as kernel functions in the gateway system. The results of each evaluation were favorable in the sense that response time for the total system using gateways compared favorably to the response time in direct videotex access over the packet-switched public data network.>

An advanced silicon compilation system called HARP is described that creates a register-transfer language (RTL) description from a FORTRAN program. HARP contains three main processing parts: a data path synthesizer; a sequence controller synthesizer; and an RTL translator. The first synthesizer generates data paths by solving three subproblems: allocation of function units, storage elements, and interconnection units. The second synthesizer generates a microprogrammed controller and microinstructions. Since the RTL translator transforms the synthesized LSI structures into RTL descriptions which are input for a VLSI synthesizer, LSI mask patterns can be directly generated. HARP produces acceptable LSI ICs which exactly execute the input FORTRAN program. HARP's target is to construct a top-down LSI design methodology starting with fewer hardware images.>