• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.12
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• pp.5596-5615
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• 2016

Security is one of the major challenges in the Wireless Sensor Networks (WSNs). WSNs are more vulnerable to adversarial activities. All cryptographic security services indirectly depend on key management. Symmetric key management is the best key establishment process for WSNs due to the resource constraints of the sensors. In this paper, we proposed dynamic session key establishment scheme based on randomly generated nonce value and sensor node identity, in which each sensor node is equipped with session key on expire basis. The proposed scheme is compare with five popular existing key management systems. Our scheme is simulated in OMNET++ with MixiM and presented experimental results. The analytical study and experimental results show the superiority of the proposed scheme over the existing schemes in terms of energy, storage, resilience and communication overhead.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.11-17
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• 2018

This study reports on a production experiment designed to investigate how Korean speaking learners of English produce English forms ending in stops. In a repetition experiment, Korean participants listened to English nonce words ending in a stop and repeated what they heard. English speakers were recruited for the same task as a control group. The experimental result indicated that the transcriptions of the Korean productions by English native speakers showed vowel insertion in only 3% of productions although the pronunciation of English final stops showed that noise intervals after the closure of final stops were significantly longer for Korean speakers than for English speakers. This finding is inconsistent with the loanword data where 49% of words showed vowel insertion. It is also not compatible with the perceptual similarity approach, which predicts that because Korean speakers accurately perceive an English final stop as a final consonant, they will insert a vowel to make the English sound more similar to the Korean sound.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.101-110
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• 2018

This study aimed to show that Selkirk's concept of resyllabification offers a better analysis than Kahn's ambisyllabification to account for phonetic resyllabification. We conducted two production experiments to investigate the acoustic characteristics of the English /s/ in real words and nonce words. Ten English native speakers and six English native speakers participated in experiment 1 and experiment 2, respectively. Three acoustic cues - frication duration, center of gravity and aspiration duration of word-medial /s/ - were measured. We found that these three cues of the word-medial /s/ were realized significantly differently depending on the stresshood and openness of the preceding syllable. We preferred Selkirk's resyllabification to Kahn's ambisyllabification to explain this result because the word-medial and intervocalic /s/ behaved as the coda (as opposed to the onset) when the preceding syllable was stressed and open. The result thus suggested that two conditions must be met for the resyllabification rule to apply in English: a word-medial consonant is resyllabified only when its preceding syllable is stressed and open.

• Journal of English Language & Literature
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• v.55 no.6
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• pp.1193-1220
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• 2009

This study examined the impact of sonority profiles, positional differences and L2 proficiency on Korean EFL learners' perception of English biconsonantal clusters, using nonce words. The overall results showed that major predictions of the sonority-based typological markedness on consonant clusters were supported, as obstruent plus sonorant and sonorant plus obstruent sequences were better perceived than obstruent only or sonorant only sequences. Yet, some consonant clusters did not show a preference for sonority profiles. Positional effects were also confirmed, as word-initial biconsonantal clusters were better perceived than wordfinal ones across all the participant groups. Participants' English proficiency turned out to be also important in the perception of consonant clusters, since university students' mean rate of accuracy was highest, followed by that of high school students, which in turn followed by that of middle school students. Further, the effects of other factors like frequency and stimuli on speech perception were also addressed, along with some implications for future research.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.256-259
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• 2003

This paper presents mutual authentication scheme between user and network on mobile communications using public key scheme based on counter, and simultaneously shows key agreement between user and user using random number for secure communications. This is also a range of possible solutions to authentication and key agreement problem-authentication and key agreement protocol based on nonce and count, and secure end-to-end protocol based on the function Y=f(.)$\^$1/, C$\^$i/ is count of user I, and f(.) is one way function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4060-4075
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• 2019

ACORN is an authenticated encryption algorithm proposed as a candidate in the currently ongoing CAESAR competition. ACORN has a good performance on security and efficiency which has been a third-round candidate. This paper mainly concentrates on the security of ACORN under the forgery attack and the non-repudiation of ACORN. Firstly, we analyze the differential properties of the feedback function in ACRON are analyzed. By taking advantage of these properties, the forgery attacks on round-reduced ACORN are proposed with a success probability higher than $2^{-128}$ when the number of finalization rounds is less than 87. Moreover, the non-repudiation of ACRON in the nonce-reuse setting is analyzed. The known collision can be used to deny the authenticated message with probability $2^{-120}$. This paper demonstrates that ACORN cannot generate the non-repudiation completely. We believe it is an undesirable property indeed.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.2
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• pp.81-85
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• 2009

In VANET, it is required one-way broadcast transmission because vehicles move at high speed and warning messages need to broadcast. our protocol employs digital signatures to authenticate nodes along the path. this prevents impersonation attacks and message modification attacks. our protocol also employs the node list to recognize intermediate nodes of the path. The node list, the time, and the nonce can prevent replay attacks.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.40-42
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• 2005

최근 XML을 기반으로 한 웹서비스는 인터넷 전자상거래와 인터넷을 기반으로 한 서비스통합 등 다양한 분야에서 활용되고 있으며 웹서비스를 이용한 메시지 및 문서를 안전하게 송수신 하기위해 XKMS기반 하에 XML전자서명, XML암호화 등이 표준화 되어 있다. 그러나 웹서비스를 위한 XML기반 PKI서비스인 XKMS는 PKI와의 연동방안이 제시되어 있지 않으며 PKI와 XKMS간의 상호인증이 보장되어 있지 않고 서비스거부공격과 재연공격 등에 취약점이 있는 등 여러 가지 취약점이 분석되고 있다. 본 논문에서는 CA발행 공인인증서를 활용한 XKMS와 PKI서버간의 상호인증방안을 제시하고 메시지 송수신 시 nonce값을 이용하여 재연공격을 방지할 수 있는 메시지 형식을 정의함으로써 보다 안전하게 XKMS PKI가 연동을 하는데 도움이 되고자 한다.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.189-199
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• 2005

Now it is increasing the necessity for micropayment system according to activation for trade on internet. Because of the reason, it is requesting safety for personal information as well as for payment cost. But current micropayment systems cannot support anonymity or have heavy overheads in payment process. This paper suggests a micropayment system to keep anonymity of users and also to keep payment cost safe. The proposed system is to use blind signature anonymous ID which is combined nonce with an encryption of personal information. It also keeps payment cost of users by reconfirmation payment cost and product from certification and increases the computational efficiency by using secret key and session key instead of public key.

• ETRI Journal
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• v.28 no.4
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• pp.444-452
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• 2006

Biometric-based authentication can provide a strong security guarantee of the identity of users. However, the security of biometric data is particularly important as any compromise of the biometric data will be permanent. In this paper, we propose a secure and efficient protocol to transmit fingerprint images from a fingerprint sensor to a client by exploiting the characteristics of the fingerprint images. Because the fingerprint sensor is computationally limited, a standard encryption algorithm may not be applied to the full fingerprint images in real-time to guarantee the integrity and confidentiality of the fingerprint images transmitted. To reduce the computational workload on the resource-constrained sensor, we apply the encryption algorithm to a nonce for integrity and to a specific bitplane of each pixel of the fingerprint image for confidentiality. Experimental results show that the integrity and confidentiality of the fingerprint images can be guaranteed without any leakage of the fingerprint ridge information and can be completed in real-time on embedded processors.