• Journal of Communications and Networks
• /
• v.18 no.2
• /
• pp.190-200
• /
• 2016

In this paper, we consider some aspects of binding properties that bind an anonymous user with messages. According to whether all the messages or some part of the messages are bound with an anonymous user, the protocol is said to satisfy the full binding property or the partial binding property, respectively. We propose methods to combine binding properties and anonymity-based authenticated key agreement protocols. Our protocol with the full binding property guarantees that while no participant's identity is revealed, a participant completes a key agreement protocol confirming that all the received messages came from the other participant. Our main idea is to use an anonymous signature scheme with a signer-controlled yet partially enforced linkability. Our protocols can be modified to provide additional properties, such as revocable anonymity. We formally prove that the constructed protocols are secure.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.6
• /
• pp.1319-1328
• /
• 2018

A blockchain system developed for crypto-currency has attractive characteristics, such as de-centralization, distributed ledger, and partial anonymity, making itself adopted in various fields. Among those characteristics, partial anonymity strongly assures privacy of users, but side effects such as abuse of crime are also appearing, and so countermeasures for circumventing such abuse have been studied continuously. In this paper, we propose a machine-learning based method for classifying smart contracts in Ethereum regarding their functions and design patterns and for identifying user behaviors according to them.

• The Journal of Society for e-Business Studies
• /
• v.20 no.1
• /
• pp.217-241
• /
• 2015

One of the challenges in online community management is what level of perceived anonymity can be granted to encourage active participation from members while discouraging unhealthy activities. Few studies developed a scheme of anonymity and investigated how different levels of anonymity influence community activities. This study develops a classification scheme of anonymity encompassing the following three different levels : (1) real name(no anonymity), (2) nickname (partial anonymity), and (3) random assignment of a temporal ID (complete anonymity). Then, it examines how different levels of anonymity influence trust and perceived risk, which in turn affect virtual team performance. A series of laboratory experiments were performed, manipulating the levels of anonymity, in the context of well-structured communities that allow prior interactions among community members. The data was collected from 364 laboratory participants and analyzed using ANOVA and PLS. The results indicate that the difference of anonymity between (2) and (3) had not be significant and the only (1) could not guarantee the anonymity. The impact of anonymity on trust and perceived risk could not be significant in this situation. These findings could contribute to make more beneficial member identification strategies in online community practice.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.6C
• /
• pp.645-650
• /
• 2006

GSM(Global System for Mobile communications) provides mobile users with portability and convenience as the most popular standard for mobile phones in the world. However, GSM system has the problem that can't normally authenticate a user by the exposure of IMSI(International Mobile Subscriber Identity) of Ms(Mobile station) during the user authentication procedure. In this paper, we propose secure user authentication by preventing the exposure if IMSI via transfer the encrypted IMSI from the HLR(Home Location Register) and making the only network entities verified from the HLR use the IMSI value, as the modified mechanism based on the original user authentication protocol to solve this authentication problem. Also the proposed mechanism provides fast user authentication without changing the architecture between new VLR and old VLR in the original GSM user authentication protocol as well as user's anonymity by using a temporary ID.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.1 s.39
• /
• pp.177-184
• /
• 2006

The sensors in a ubiquitous network are limited because of the low power and ultra light weight, so many studies have revolved around the sensor. This study improves the process of the registration and authorization and suggests a way to minimize discloser of privacy by using an alias. We introduce RA(Relay Agent) for the restrict function of sensor node, and improve anonymity for private information of each sensor node by assigning alias from SM(Service Manager) in procedure of registration and authentication. The privacy of sensor node is secure in procedure of registration, authentication, and communication between nodes. We could improve the level of security with the only partial increment of computation power of RA and SM without an increase in the amount of sensor nodes.

• Journal of Communications and Networks
• /
• v.18 no.6
• /
• pp.948-961
• /
• 2016

Internet protocol (IP) spoofing is a serious problem on the Internet. It is an attractive technique for adversaries who wish to amplify their network attacks and retain anonymity. Many approaches have been proposed to prevent IP spoofing attacks; however, they do not address a significant deployment issue, i.e., filtering inefficiency caused by a lack of deployment incentives for adopters. To defeat attacks effectively, one mechanism must be widely deployed on the network; however, the majority of the anti-spoofing mechanisms are unsuitable to solve the deployment issue by themselves. Each mechanism can work separately; however, their defensive power is considerably weak when insufficiently deployed. If we coordinate partially deployed mechanisms such that they work together, they demonstrate considerably superior performance by creating a synergy effect that overcomes their limited deployment. Therefore, we propose a universal anti-spoofing (UAS) mechanism that incorporates existing mechanisms to thwart IP spoofing attacks. In the proposed mechanism, intermediate routers utilize any existing anti-spoofing mechanism that can ascertain if a packet is spoofed and records this decision in the packet header. The edge routers of a victim network can estimate the forgery of a packet based on this information sent by the upstream routers. The results of experiments conducted with real Internet topologies indicate that UAS reduces false alarms up to 84.5% compared to the case where each mechanism operates individually.

• The Journal of Society for e-Business Studies
• /
• v.23 no.3
• /
• pp.13-32
• /
• 2018

Btcoin has made a big progress through anonymity, decentralized authority, sharing economy, multi-ledger book-keeping, block-technology and the convenient financial vehicle. Bitcoin has the characteristics of mining and supply by decentralized suppliers, limited supply quantity and the partial money-like function as well as gold. The paper studies the hedge and safe-haven of Bitcoin and gold on daily frequency data over the period of July 20, 2010-Dec. 27, 2017 employing Asymmetric Vector GARCH. It finds that gold has the hedge and safe-haven against inflation and capital markets while Bitcoin has the weak hedge and the weak safe-haven. It shows insignificant effects of inflations of US and Korea on the volatilities of Bitcoin and gold. It also suggests the necessity of clearing of vagueness behind the anonymity for fair and transparent trade through the law application in the absence or fault in law (Lucken im Recht). following the spirit of the living constitution (lebendige gutes Recht oder Vorschrift). The relevant institutions are hoped to be given some of obligations such as registration, minimum required capital. report, disclosure, explanation, compliance and governance with autonomous corresponding rights. The study also suggests the reestablishment of the relevant financial law and taxation law. The hedge would not be successfully accomplished without the vigilant cautions of investors.