著者

Daiki CHIBA Ayako AKIYAMA HASEGAWA Takashi KOIDE Yuta SAWABE Shigeki GOTO Mitsuaki AKIYAMA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103.D, no.7, pp.1493-1511, 2020-07-01 (Released:2020-07-01)

参考文献数

70

被引用文献数

3

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Internationalized domain names (IDNs) are abused to create domain names that are visually similar to those of legitimate/popular brands. In this work, we systematize such domain names, which we call deceptive IDNs, and analyze the risks associated with them. In particular, we propose a new system called DomainScouter to detect various deceptive IDNs and calculate a deceptive IDN score, a new metric indicating the number of users that are likely to be misled by a deceptive IDN. We perform a comprehensive measurement study on the identified deceptive IDNs using over 4.4 million registered IDNs under 570 top-level domains (TLDs). The measurement results demonstrate that there are many previously unexplored deceptive IDNs targeting non-English brands or combining other domain squatting methods. Furthermore, we conduct online surveys to examine and highlight vulnerabilities in user perceptions when encountering such IDNs. Finally, we discuss the practical countermeasures that stakeholders can take against deceptive IDNs.

著者

Ayako Akiyama Hasegawa Takuya Watanabe Eitaro Shioji Mitsuaki Akiyama Tatsuya Mori

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.28, pp.1030-1046, 2020 (Released:2020-12-15)

参考文献数

42

被引用文献数

1

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Online service providers exert tremendous effort to protect users' accounts against sensitive data breaches. Although threats from complete outsiders, such as account hijacking for monetization, still occur, recent studies have shed light on threats to privacy from insiders. In this study, we focus on these latter threats. Specifically, we present the first comprehensive study of an attack from insiders that identifies the existence of a target's account by using the target's email address and the insecure login-related messages that are displayed. Such a threat may violate intimates' or acquaintances' privacy because the kinds of service accounts a user has implies his/her personal preferences or situation. We conducted surveys regarding user expectations and behaviors on online services and an extensive measurement study of login-related messages on online services that are considered sensitive. We found that over 80% of participants answered that they have sensitive services and that almost all services were vulnerable to our attack. Moreover, about half the participants who have sensitive services were insecurely registered on them, thus could be potential victims. Finally, we recommend ways for online service providers to improve login-related messages and for users to take appropriate defensive actions. We also report our responsible disclosure process.

著者

Keika MORI Takuya WATANABE Yunao ZHOU Ayako AKIYAMA HASEGAWA Mitsuaki AKIYAMA Tatsuya MORI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103.D, no.7, pp.1541-1555, 2020-07-01 (Released:2020-07-01)

参考文献数

33

被引用文献数

1 2

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This work aims to determine the propensity of password creation through the lens of language spheres. To this end, we consider four different countries, each with a different culture/language: China/Chinese, United Kingdom (UK) and India/English, and Japan/Japanese. We first employ a user study to verify whether language and culture are reflected in password creation. We found that users in India, Japan, and the UK prefer to create their passwords from base words, and the kinds of words they are incorporated into passwords vary between countries. We then test whether the findings obtained through the user study are reflected in a corpus of leaked passwords. We found that users in China and Japan prefer dates, while users in India, Japan, and the UK prefer names. We also found that cultural words (e.g., “sakura” in Japan and “football” in the UK) are frequently used to create passwords. Finally, we demonstrate that the knowledge on the linguistic background of targeted users can be exploited to increase the speed of the password guessing process.

著者

Kazuki Hotta Kentaro Kamiya Ryosuke Shimizu Misako Yokoyama Misao Nakamura-Ogura Minoru Tabata Daisuke Kamekawa Ayako Akiyama Michitaka Kato Chiharu Noda Atsuhiko Matsunaga Takashi Masuda

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

vol.54, no.2, pp.59-63, 2013 (Released:2013-04-03)

参考文献数

31

被引用文献数

13 34

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The purpose of this study was to clarify the acute effects of a single session of stretching exercises on vascular endothelial function and peripheral circulation in patients with acute myocardial infarction. This study evaluated 32 patients (mean age, 66 ± 9 years) who received phase I cardiac rehabilitation after acute myocardial infarction. Five types of stretching exercises were performed on the floor: wrist dorsiflexion, close-legged trunk flexion, open-legged trunk flexion, open-legged lateral trunk bending, and cross-legged trunk flexion. Each exercise entailed a 30-second stretching followed by a 30-second relaxation, and was repeated twice. Low- and high-frequency components (LF and HF) of heart rate variability (LF, 0.04-0.15 Hz; HF, 0.15-0.40 Hz) were analyzed, and HF and LF/HF were used as indices of parasympathetic and sympathetic nervous activities, respectively. Reactive hyperemia peripheral arterial tonometry (RH-PAT) index was measured and used as a parameter for vascular endothelial function. Transcutaneous oxygen pressure (tcPO2) on the right foot and chest was also measured, and the Foot-tcPO2/Chest-tcPO2 ratio was used as a parameter for peripheral circulation. The HF, RH-PAT index, and Foot-tcPO2/Chest-tcPO2 ratio were significantly higher after the exercises than before (P < 0.05, P < 0.01, and P < 0.05, respectively). There was no significant difference in the LF/HF ratio measured before and after stretching exercises. These findings demonstrate that stretching exercises improve vascular endothelial function and peripheral circulation in patients with acute myocardial infarction.