Abstract There are many kinds of online services in our daily life, such as e-mail and messenger. When we link to a remote host, we are required to login first, supplying a username and the corresponding password, and then obtain the resources or have services. Most commonly, we might use a smart card to assistant us to login a remote site.... There are many kinds of online services in our daily life, such as e-mail and messenger. When we link to a remote host, we are required to login first, supplying a username and the corresponding password, and then obtain the resources or have services. Most commonly, we might use a smart card to assistant us to login a remote site. In 1981, Lamport proposed a remote authentication scheme for communication through insecure channels. Lu and Cao further proposed an efficient scheme based on quadratic residue in 2005. In the Lu-Cao scheme, it is unnecessary for the server to store the verifica-tion table. However, some obvious drawbacks are that users cannot freely choose their own passwords and their scheme is inefficient due to complex computations. In this paper, we proposed an improvement of the Lu-Cao scheme to make it more efficient and secure. Read More Read Less

Abstract Keyphrases precisely express the primary top-ics and themes of documents and are valuable for cataloging and classification. Manually assigning keyphrases to existing documents is a tedious task; therefore, automatic keyphrase generation has been extensively used to classify digital docu-ments. Existing automatic keyphrase generation algorithms are limited in assigning semantically relevant keyphrases to documents. In this paper we have proposed a... Keyphrases precisely express the primary top-ics and themes of documents and are valuable for cataloging and classification. Manually assigning keyphrases to existing documents is a tedious task; therefore, automatic keyphrase generation has been extensively used to classify digital docu-ments. Existing automatic keyphrase generation algorithms are limited in assigning semantically relevant keyphrases to documents. In this paper we have proposed a methodology to refine the result set of automatically generated keyphrases by Keyphrase Extraction Algorithm (KEA++), so that the key-phrases accurately and precisely represent the content of the document. Our approach is an additional layer at the top of KEA++ and exploits semantic relationships and hierarchical structure of the controlled vocabulary to filter out irrelevant keyphrases from the result set generated by KEA++. The methodology was applied on different sets of academic publications for evaluation. Evaluation demonstrates that the proposed refinement methodology improves the quality of generated keyphrases. Read More Read Less

Abstract Textual formalisms, visual formalisms, or both types of formalisms can be used to develop a formal model. The exact syntax and semantics of textual formalisms reduce ambiguity and increase formulation precision. This has as side effect that textual formalisms can become complex and suitable for limited audiences only. Visual formalisms consist of graphical notations with formal semantics. The intuitive and... Textual formalisms, visual formalisms, or both types of formalisms can be used to develop a formal model. The exact syntax and semantics of textual formalisms reduce ambiguity and increase formulation precision. This has as side effect that textual formalisms can become complex and suitable for limited audiences only. Visual formalisms consist of graphical notations with formal semantics. The intuitive and well-organized char acter of such models improves their com-prehensibility and eases commu nication. Unfortunately, visual formalisms can become unreadable when the complexity or number of formalisms increases. Conversion patterns are intro-duced to enable conversion of textual to visual formalisms and vice versa. These patterns can be applied to benefit from the advantages of both ways to represent formalisms. The Object-Role Modeling (ORM) language has been used to develop the visual patterns and the textual formalisms are founded in set theory. While the primary focus of this paper is on the theoretic coupling between textual and visual formalisms, the presented patterns are also materialized and evaluated in two applica-tions. First, an ORM model of the ISO/IEC 19763-5 standard to register information of process models is converted to a textual formal model. Sec ond, a textual formal model of an information market is converted to an ORM variant. Read More Read Less

Abstract This paper focuses on authentication with three types of entities: a user who sends an authentication request, a service provider who receives and verifies the request, and a database who supplies the service provider with information for verifying the request. This paper presents novel authentication protocols that satisfy the following important properties: (1) se-cure against replay attacks and (2) the... This paper focuses on authentication with three types of entities: a user who sends an authentication request, a service provider who receives and verifies the request, and a database who supplies the service provider with information for verifying the request. This paper presents novel authentication protocols that satisfy the following important properties: (1) se-cure against replay attacks and (2) the database cannot identify which user is authenticating. First, we show a protocol which satisfies Properties (2). Second, we show a protocol which satisfies Properties (1) and (2). A key idea of our authentication protocols is to use private information retrieval (PIR) [Chor et al. J. ACM, 1998]. Read More Read Less

Abstract As a consequence of rapid technological de-velopment, the normally isolated medical sensor platform is gradually being integrated into networks. However, most ubiq-uitous or mobile health systems are lacking a system that com-bines both network security and QoS (Quality of Service). This paper investigates the possible security and QoS methods of a ubiquitous healthcare network platform in OSI (Open System... As a consequence of rapid technological de-velopment, the normally isolated medical sensor platform is gradually being integrated into networks. However, most ubiq-uitous or mobile health systems are lacking a system that com-bines both network security and QoS (Quality of Service). This paper investigates the possible security and QoS methods of a ubiquitous healthcare network platform in OSI (Open System Interconnections)-layers. This network platform is based on the Wireless Overlay Networks (WON) Bluetooth, 802.11 and 802.16 over IPv6 network, and provides a secure and stable U-healthcare platform by including the application of healthcare sensors with RFID, U-healthcare PDA, VoIPv6, falling detection, and patient orientation. Read More Read Less