Akio Shiibashi

Multi-layered Data Consistency Technology, An Enhanced Autonomous Decentralized Data Consistency Technology for IC Card Ticket System

The vulnerability discovery process for a program describes the rate at which the security vulnerabilities are discovered. Being able to predict the vulnerability discovery process allows developers to adequately plan for resource allocation needed to develop patches for them. It also enables the users to assess the security risks. Thus there is a need to develop a model of the discovery process that can predict the number of vulnerabilities that are likely to be discovered in a given time frame. Recent studies have produced vulnerability discovery process models that are suitable for a specific version of a software. However, these models may not accurately estimate the vulnerability discovery rates for a software when we consider successive versions, hi this paper, we propose a new approach for quantitatively modeling the vulnerability discovery process, based on shared source code measurements among multi-version software systems. Such a modeling approach can be used for assessing security risk both before and after the release of a version. The applicability of the approach is examined using two open source software systems, viz., Apache HTTP Web server and Mysql DataBase Management System (DBMS). We have examined the relationship between shared code size and shared vulnerabilities between two successive versions. We observe that vulnerabilities continue to be discovered for an older version because part of its code is shared by the newer and more popular later version. Thus, even when the installed base of an older version has declined, vulnerabilities applicable to it are still discovered. Our results are validated using the source code and vulnerability data for two major versions of Apache HTTP Web server and two major versions of Mysql DBMS.

High-speed processing in wired-and-wireless integrated autonomous decentralized system and its application to IC card ticket system

The automatic fare collection systems need both high performance and high reliability. High performance is one of the most expected functions on the automatic fare collection gates (AFCGs) handling the highly dense passengers during rush hours. Reliability is also indispensable because the tickets are equivalent to money. For a wireless IC card ticket system, expected to improve the passengers’ convenience and to reduce the maintenance cost, is difficult to meet these two requirements because of wireless communications between an IC card and an AFCG. This paper introduces the autonomous decentralized system as the solution and how it is applied to the system. Then, two models are prepared and simulated to evaluate the efficiency, especially high-speed processing. The technologies are implemented into the “Suica” system at East Japan Railway Company and have proven the effectiveness.

Research of Reliability Technology in Heterogeneous Autonomous Decentralized Assurance Systems

Reliability, the conventional measure, is defined as whether a system can continue the operation without failure. It indicates 0 or 1 and is not suitable for systems with functions gradually increasing and decreasing. Functional reliability, on the other hand, scales a system as integration of functions by subsystems. So it can reflect how the system is changing. autonomous decentralized systems, for example, can continue the operation even when some of the subsystems fail. In this case, functional reliability is more appropriate to grasp the state of the system. This paper introduces functional reliability to evaluate the IC card ticket system, one of the autonomous decentralized assurance systems. Two models of the centralized system model and the decentralized system model are prepared, simulated, and compared. According to the results, the decentralized system model shows higher functional reliability. In reality, the IC card ticket system is operating very well without any fatal errors, which proves the usefulness of functional reliability

Technologies Toward High Performance and High Reliability in Suica System

Railway transportation is required to serve without rest every day. In Japan trains and platforms are terribly crowded every morning and evening, so that the Automatic Fare Collection (AFC) Systems need high performance. On the other hand, the systems need high reliability since the tickets they process are equivalent to cash. This paper introduces Autonomous Cooperative Processing Technology for high performance and Autonomous Decentralized Data Consistency Technology for high reliability. These technologies are applied to Suica System, an AFC system in East Japan Railway Company. The system has been running for about ten years, and serious troubles are not filed. That is, the technologies are proven to be effective.

Autonomous Decentralized Multi-layered Data Consistency Technology and its application

With the diversification of users and systems requirements, the integration of control and information systems has become more and more important. In these systems, assurance is required to achieve high performance of real-time control and high reliability of the transaction process. However, in high load transaction conditions, it is difficult for conventional centralized systems to achieve data consistency during real-time processing. In this paper, “Autonomous Decentralized Multi-layered Data Consistency Technology (ADMLDCT)”is proposed, which is based on heterogeneous “Data Fields (DFs)”with different process times of data consistence. The consistent data and inconsistent data coexist in the system. In this technology, each layer autonomously makes data consistent and cooperates with other layers according to the different stay time of data. As a result, both the recovery of inconsistent data and congestion of each layer can be improved. These technologies have been applied to the IC (Integrated Circuit) Card ticket system of East Japan Railway Company, where the effectiveness of the technology has been proved.