Browsing by Author "Yeh, TC"

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A secure one-time password authentication scheme using smart cards
(2002-11-01)
Yeh, TC
;
Shen, HY
;
Hwang, JJ
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Using the great one-time password concept,, the widely utilized one-way authentication scheme S/Key provides well protection against replay attacks. In this paper, S/key is enhanced to secure transactions in a critical environment. The proposed scheme is free from any of server spoofing attacks, pre-play attacks, and off-line dictionary attacks. A session key here is also established to provide confidentiality. Moreover, simplicity and efficiency are taken into consideration from the user's point of view. A smart card is applied to simplify the user login process and only the hash function is used to keep its efficiency. Therefore, the scheme proposed hereinafter is able to build a safer shield for sensitive transactions like on-line banking or on-line trading in bonds and securities.
ICA-based spatiotemporal approach for single-trial analysis of postmovement MEG beta synchronization
(2003-12-01)
Lee, PL
;
Wu, YT
;
Chen, LF
;
Chen, YS
;
Cheng, CM
The extraction of event-related oscillatory neuromagnetic activities from single-trial measurement is challenging due to the non-phase-locked nature and variability from trial to trial. The present study presents a method based on independent component analysis (ICA) and the use of a template-based correlation approach to extract Rolandic beta rhythm from magnetoencephalographic (MEG) measurements of right finger lifting. A single trial recording was decomposed into a set of coupled temporal independent components and corresponding spatial maps using ICA and the reactive beta frequency band for each trial identified using a two-spectrum comparison between the postmovement interval and a reference period. Task-related components survived dual criteria of high correlation with both the temporal and the spatial templates with an acceptance rate of about 80%. Phase and amplitude information for noise-free MEG beta activities were preserved not only for optimal calculation of beta rebound (event-related synchronization) but also for profound penetration into subtle dynamics across trials. Given the high signal-to-noise ratio (SNR) of this method, various methods of source estimation were used on reconstructed single-trial data and the source loci coherently anchored in the vicinity of the primary motor area. This method promises the possibility of a window into the intricate brain dynamics of motor control mechanisms and the cortical pathophysiology of movement disorder on a trial-by-trial basis. (C) 2003 Elsevier Inc. All rights reserved.
Improvement on Peyravian-Zunic's password authentication schemes
(2002-04-01)
Hwang, JJ
;
Yeh, TC
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Peyravian and Zunic (2000) presented two schemes for protecting password transmission and password change respectively. Like the traditional authentication scheme using passwords, the two new schemes are also vulnerable to attacks like guessing attacks, server spooling, and server data eavesdropping, This paper will give demonstrations on what have caused to these drawbacks, and more of that, two improved schemes are also proposed which are free from worries of those possible attacks.
Securing on-line credit card payments without disclosing privacy information
(2003-05-01)
Hwang, JJ
;
Yeh, TC
;
Li, JB
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Two revisions of the original Secure Electronic Transaction (SET) protocol are proposed to conceal cardholders' identities in the electronic marketplace in which cardholders' trust for banks can be reduced to a minimum. Constrained by being extensions of the existing card payment networks to the Internet, most on-line credit card payment schemes in use or proposed in recent papers assume the sensitive card information could be disclosed to all the participating banks. The assumption used to work well in traditional credit card payments before. However, negative impacts such as banking scandals, closure programs due to poor management, and security problems with Internet banking are all undermining cardholders' trust in banks. The issuer is the trusted bank selected by the cardholder, but the acquirer is not. To reveal the cardholder's sensitive card information to every possible acquirer implies potential risk. Based on the need-to-know principle, the two revisions are proposed to relax the assumption mentioned above. In our solutions, the sensitive card information is well protected along the way and can be extracted only by the issuer. A cardholder needs only to select a trustworthy issuer, instead of worrying about the possible breakdowns of every involved acquirer. The cost to achieve our more. secure schemes demands only minor information modifications on the legacy system. (C) 2002 Elsevier Science B.V. All rights reserved.