• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.31-35
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• 2000

An nonlinear observer-based longitudinal control law for vehicles is presented in this paper. It is assumed that for vehicle i knows only the distance between vehicle i and the preceding vehicle, i-1. An nonlinear state observer for vehicle I is developed to estimate the velocity and acceleration of the preceding vehicle, i-1. The communication of the position, velocity, and acceleration information is not used in the proposed method. It will be shown by mathematical analysis that the longitudinal control of vehicle can be implemented without an communication of the informations. It will be proven that the observation errors of the nonlinear states converge to zero asymptotically. To show the effectiveness of the proposed method, the simulation results are presented for the longitudinal control of the vehicle.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.5
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• pp.73-92
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• 2005

Joux's tripartite key agreement protocol is one of the most prominent developments in the area of key agreement. Although certificate-based and ID-based authentication schemes have been proposed to provide authentication for Joux's protocol, no provably secure password-based one round tripartite key agreement protocol has been proposed yet. We propose a secure one round password-based tripartite key agreement protocol that builds on Joux's protocol and adapts PAK-EC scheme for password-based authentication, and present a proof of its security.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.3-16
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• 2010

Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.17-22
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• 2021

With the application of the Data 3 method, the scope of the use of pseudonym information has expanded. In the case of pseudonym information, a specific individual can be identified by linking and combining with various data, and personal information may be leaked due to incorrect use of the pseudonym information. In this paper, we propose the scope of use of data is subdivided and a differentiated pseudonym information processing method according to the scope. For the study, the formula was modified by using zero-knowledge proof among the pseudonym information processing methods, and when the proposed formula was applied, it was confirmed that the performance improved by an average of 10% in terms of verification time compared to the case of applying the formula of the existing zero-knowledge proof.

• Journal of Advanced Navigation Technology
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• v.5 no.1
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• pp.1-10
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• 2001

Speech has a good characteristics of which car drivers busy to concern with miscellaneous operation can make use in convenient handling and manipulating of devices. By utilizing this, this works proposes a speaker verification method for protecting cars from being stolen and identifying a person trying to access critical on-line services. In this, continuant phonemes recognition which uses language information of speech and MLP(mult-layer perceptron) which has some advantages against previous stochastic methods are adopted. The recognition method, though, involves huge computation amount for learning, so it is somewhat difficult to adopt this in speaker verification application in which speakers should enroll themselves at real time. To relieve this problem, this works presents a solution that introduces speaker cohort models from speaker verification score normalization technique established before, dividing background speakers into small cohorts in advance. As a result, this enables computation burden to be reduced through classifying the enrolling speaker into one of those cohorts and going through enrollment for only that cohort.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.580-587
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• 2016

In the purpose of suggesting the necessity and proper method of providing the standard reference material for acquiring the aircraft pilot license, this study provides the FAA and ROKAF case study, and positively analyzes the materials of 178 pilots and student pilots who acquired the aircraft pilot license. The result of case study shows that compared to the case of Korea which the restriction on the standard reference material providing exists, the FAA(Federal Aviation Administration) and ROKAF are currently providing the standard reference material. Additionally, the result of positive analysis indicates the fact that the necessity of standard reference material providing is well recognized and its importance also found to be remarkably high. These results represent that the standard reference material providing is necessary for training competent aircraft pilots. Also, this will mitigate the current shortage of aircraft pilots due to the rapid growth of air transportation industry, and this will play an important role in preventing diverse aircraft-related accidents.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.23-32
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• 2013

As the mobile communication technology is developed, the services for communication between the mobile devices are provided, and the amount of usage is increasing tremendously. For the device-to-device communication, the device should be verified if it is a service member. The existing verification schemes include interactions with the third party, while this may cause the problems that the bandwidth is dissipated and the devices which are out of the communication range of the base station cannot communicate with other devices. To solve such problems, we propose a new scheme for verification between mobile devices without interaction of third party. For the proposed scheme, we develop and employ a new zero-knowledge proof protocol, which verifies the device's membership and its expiration time. Furthermore, the scheme guarantees privacy of the mobile device since it checks the encrypted verification message without decrypting, and protects replaying attack since it uses challenge-response method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.547-557
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• 2015

The security of all cryptographic algorithms and protocols is based on the confidentiality of secret keys. Key management mechanism is an indispensable part of the cryptographic system and this deals with the generation, exchange, storage, use, and replacement of keys. Within the key management mechanism there are key derivation functions (KDFs) which derive one or more keys from a master key. NIST specifies three families of PRF-based KDFs in SP 800-108. In this paper, we examine the difference of security models between the KDFs and the encryption modes of operations. Moreover we focus on the provable security of PRF-based KDFs according to input types of counters, and show that the counter and feedback modes of KDFs using XOR of counters are insecure, while these modes using concatenation of counters are secure.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.66-74
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• 2021

With the development of the Internet, user authentication technology that proves me online is improving. Existing ID methods pose a threat of personal information leakage if the service provider manages personal information and security is weak, and the information subject is to the service provider. In this study, as online identification technology develops, we propose a DID-based self-authentication model to prevent the threat of leakage of personal information from a centralized format and strengthen sovereignty. The proposed model allows users to directly manage personal information and strengthen their sovereignty over information topics through VC issued by the issuing agency. As a research method, a self-authentication model that guarantees security and integrity is presented using a decentralized identifier method based on distributed ledger technology, and the security of the attack method is analyzed. Because it authenticates through DID Auth using public key encryption algorithms, it is safe from sniffing, man in the middle attack, and the proposed model can replace real identity card.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.6
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• pp.69-78
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• 2004

During the last decade, security models have been defined for two- and three-parity key exchange protocols. Currently there is a growing research interest in security models for group key management schemes. While various security models and provably secure protocols have been proposed for distributed group key exchange schemes, no results are hewn for centralized group key distribution schemes in spite of their theoretical and practical importance. We describe security requirements and a formal security model for centralized group key distribution scheme: we define the model on the channel controlled by adversaries with the ability of strong user corruption. In the security model, we propose a conversion module which can transform centralized tree-based group key distribution schemes in the literature to provably secure centralized tree-based group key distribution schemes.