• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.462-466
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• 2005

Dynamic (On-line) signature verification system consists of preprocessing, feature extraction, comparison and decision process for internal processing, and registration and verification windows for the user interface. We describe an implementation and design for an advanced dynamic signature verification system. Also, we suggest the method of feature extraction, matching algorithm, efficient user interface and an objective criteria for evaluating the performance.

• Journal of Electrical Engineering and information Science
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• v.2 no.4
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• pp.37-45
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• 1997

With rapid increase of information requirements from various application areas, there has been much research on dynamic information storage structures that effectively support insertions, deletions and updates. In this appear we evaluate the performance of he existing dynamic signature file methods such as the S-tree, Quick Filter and HS file and provide guidelines for the most effective usage to a given operational environment. We derive analytic performance evaluation models of the storage structures based on retrieval time, storage overhead and insertion time. We also perform extensive experiments with various data distributions such as uniform, normal and exponential distributions. The relationships among various performance parameters are throughly investigated. We show through performance comparison based on analytic models and experiments that regardless of data distribution, the HS file significantly improves performance in both the retreival time and the storage overhead over S-tree and Quick Filter.

• ETRI Journal
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• v.37 no.1
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• pp.138-146
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• 2015

This paper presents a new non-constraining online optical handwritten signature reconstruction system that, in the main, makes use of a transparent glass pad placed in front of a color camera. The reconstruction approach allows efficient exploitation of hand activity during a signing process; thus, the system as a whole can be seen as a viable alternative to other similar acquisition tools. This proposed system allows people with physical or emotional problems to carry out their own signatures without having to use a pen or sophisticated acquisition system. Moreover, the developed reconstruction signature algorithms have low computational complexity and are therefore well suited for a hardware implementation on a dedicated smart system.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.49-55
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• 2016

In a delegate authentication, a user can lend his/her own authentication data to the third parties to let them be authenticated instead of himself/herself. The user authentication schemes based on the memory of unique data such as password, are vulnerable to this type of attack. Biometric authentication could minimize the risk of delegate authentication since it uses the biometric data unique by each person. Group authentication scheme is used to prove that each group member belongs to the corresponding group. For applications such as an electronic voting or a mobile meeting where the number of group members is changing dynamically, a new group authentication method is needed to reflect the status of group in real time. In this paper, we propose biometric authentication based dynamic group signature scheme. The proposed scheme is composed of biometric key generation, group public key creation, group signature generation, group signature verification and member update protocols. The proposed member update protocol is secure against colluding attacks of existing members and could reflect group status in real time.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.663-673
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• 2005

An analysis model for the dynamics information of two-dimensional time-series patterns is described. In the proposed model, two novel transforms that visualize the dynamic characteristics are proposed. The first transform, referred to as speed equalization, reproduces a time-series pattern assuming a constant linear velocity to effectively model the temporal characteristics of the signing process. The second transform, referred to as velocity transform, maps the signal onto a horizontal vs. vertical velocity plane where the variation oi the velocities over time is represented as a visible shape. With the transforms, the dynamic characteristics in the original signing process are reflected in the shape of the transformed patterns. An analysis in the context of these shapes then naturally results in an effective analysis of the dynamic characteristics. The proposed transform technique is applied to an online signature verification problem for evaluation. Experimenting on a large signature database, the performance evaluated in EER(Equal Error Rate) was improved to 1.17$\%$ compared to 1.93$\%$ of the traditional signature verification algorithm in which no transformed patterns are utilized. In the case of skilled forgery experiments, the improvement was more outstanding; it was demonstrated that the parameter set extracted from the transformed patterns was more discriminative in rejecting forgeries

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.963-974
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• 2018

With the growing interest in cryptocurrency such as bitcoin, the blockchain technology has attracted much attention in various applications as a distributed security platform with excellent security. However, Cryptojacking, an attack that hijack other computer resources such as CPUs, has occured due to vulnerability to the Cryptomining process. In particular, browser-based Cryptojacking is considered serious because attacks can occur only by visiting a Web site without installing it on a visitor's PC. The current Cryptojacking detection system is mostly signature-based. Signature-based detection methods have problems in that they can not detect a new Cryptomining code or a modification of existing Cryptomining code. In this paper, we propose a Cryptojacking detection solution using a dynamic analysis-based that uses a headless browser to detect unknown Cryptojacking attacks. The proposed dynamic analysis-based Cryptojacking detection system can detect new Cryptojacking site that cannot be detected in existing signature-based Cryptojacking detection system and can detect it even if it is called or obfuscated by bypassing Cryptomining code.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.143-151
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• 2001

This paper investigates the development of a neural network based system for automated signature authentication that relies on an autoregressive characterization for the segments of a signature. The primary contributions of this work are tow-fold: a) the development of the neural network architecture and the modalities of training it, b) adaptation of the dynamic time warping algorithm to fomulate a new method for enabling consistent segmentation of multiple signatures from the same writer. The performance of the signature verification system has been tested using a sizable database that includes a comprehensive set of simulated and realistic forgeries. False Acceptance and False Rejection error rates of 0.78% and 1.6% respectively were obtained in tests conducted using 1920 skilled forgeries.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.129-137
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• 2004

This paper presents a signature verification method that uses Gabor filter in computing similarity between signatures. In computing similarity to compare two on-line signatures, the temporal relationship between two signatures should be computed in advance. However, conventional point matching method using DP(dynamic programming) matching consumes much computation. In this paper, we propose a fast method for computing the temporal relationship between two on-line signatures by using the phase output of Gabor Inter applied on the on-line signature signals. Two similarity measures are defined in the method: Temporal Similarity and Temporally Arranged Feature Profile Similarity. With the proposed method, Ive could compare signatures 30 times faster than conventional method using DP matching.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.45-48
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• 2009

USN(Ubiquitous Sensor Network)은 우리가 관심이 있는 모든 사물에 통신기능이 있는 무선센서(전자태그)를 부착하고 이를 통해 사물 인식정보와 주변 환경정보(온도나 습도, 압력, 충격, 오염 등)를 탐지해 이를 실시간 네트워크를 통해 센싱 데이터들을 전송, 취합, 저장, 분석하여 사용자의 현재 상황에 정보(가정, 병원, 사무실, 유통, 군사, 교통 등)를 적절히 제공해 줄 수 있는 기술 및 첨단 지능형 서비스를 통칭한다. 향후 USN 서비스는 광범위한 영역에서 활용될 전망이며, 그에 따른 사용자 인증 보안의 중요성도 크게 부각될 것이다. 이를 위해 본 논문에서는 자필 서명을 이용한 보안기술의 USN 연동 방안을 제안하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.373-376
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• 2007

This paper presents dynamic (on-line) signature verification using direction and speed information as feature information. We describe a detail method of the adjusted constant(W) in the suggested DTW for the speed between adjacent two points.