• The Journal of the Korea Contents Association
• /
• v.17 no.6
• /
• pp.32-38
• /
• 2017

Despite the opinion that certificate is useless, half of the population in Korea (approx. 35 million) get an certificate, and use it for internet banking, internet shopping, stock trading, and so on. Most users store their certificates on a usb memory or smartphone, and certificates or passwords stored on such storage media can be easily attacked and used to disguise as legitimate users. Due to these security problem of certificate, a various authentication technologies has been proposed such as smartphone owner authentication using SMS, and a personal authentication using biometric authentication. However, a safe technique is not presented yet without user password, and certificate. In this paper, I proposed a method to secure certificate/private key without a user password using a combination of USIM card and smartphone's information. Even if a hacker gets the user password, the certificate, and the private key, he can not use the certificate. User do not need to remember complex password which is a combination of alphabetic / numeric / special characters, and use his certificate safely.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.75-82
• /
• 2018

As user of mobile device increases, various user authentication methods are actively researched. The user authentication methods includes a method of using a user ID and a password, a method of using user biometric feature, a method of using location based, and a method of authenticating secondary authentication such as OTP(One Time Password) method is used. In this paper, we propose a user system which improves the problem of existing authentication method and encryption can proceed in a way that user desires. The proposed authentication system is composed of an authentication factor collection module that collects authentication factors using a mobile device, a security key generation module that generates a security key by combining the collected authentication factors, and a module that performs authentication using the generated security key module.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.309-312
• /
• 2011

본 논문에서는 유무선 통신환경의 클라이언트-서버 모델에서 바이오정보를 이용해 비밀 키 또는 비밀 정보를 실시간 공유할 수 있는 신뢰구간 기반의 바이오-암호 기법을 설계하고 분석한다. 제안하는 바이오-암호 기법은 키 결합 방식의 바이오-암호 기법의 대표적인 기법의 하나인 퍼지볼트 기법을 기본 모델로 두고 있으나, 퍼지볼트 기법의 주요 이슈인 거짓 볼트 수의 증가에 따른 인식률 저하, 고차 다항식 복원 시간의 실용성 여부, 상관 공격에의 취약을 해결하기 위하여 T-검정 기반 신뢰구간을 적용한 키 결합 방식으로 설계하였다. 실험결과는 거짓 볼트 수의 증가와 상관없이 항상 비밀 키를 획득해 보안성과 정확성이 향상되고, 이때의 수행시간도 사용자가 인지하기 힘든 작은 값으로 실시간 사용의 가능성을 높이고, 유사 바이오정보로 비밀 키를 획득할 수 없어 상관 공격에도 강인함을 확인하였다.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.9
• /
• pp.89-96
• /
• 2021

In this paper, we analyzed that the user authentication scheme for TMIS(Telecare Medicine Information System) proposed by Al-Saggaf et al. In 2019, Al-Saggaf et al. proposed authentication scheme using biometric information, Al-Saggaf et al. claimed that their authentication scheme provides high security against various attacks along with very low computational cost. However in this paper after analyzing Al-Saggaf et al's authentication scheme, the Al-Saggaf et al's one are missing random number s from the DB to calculate the identity of the user from the server, and there is a design error in the authentication scheme due to the lack of delivery method. Al-Saggaf et al also claimed that their authentication scheme were safe against a variety of attacks, but were vulnerable to password guessing attack using login request messages and smart cards, session key exposure and insider attack. An attacker could also use a password to decrypt the stored user's biometric information by encrypting the DB with a password. Exposure of biometric information is a very serious breach of the user's privacy, which could allow an attacker to succeed in the user impersonation. Furthermore, Al-Saggaf et al's authentication schemes are vulnerable to identity guessing attack, which, unlike what they claimed, do not provide significant user anonymity in TMIS.

• The Journal of the Korea Contents Association
• /
• v.16 no.8
• /
• pp.90-96
• /
• 2016

The 3390 million people, around 83% of the adult population in Korea use smartphone. Although the safety problem of the certificate has been occurred continuously, most of these users use the certificate. These safety issues as a solution to 'The owner of a mobile phone using SMS authentication technology', 'Biometric authentication', etc are being proposed. but, a secure and reliable authentication scheme has not been proposed for replace the certificate yet. and there are many attacks to steal the certificate and private key. For these reasons, security experts recommend to store the certificate and private key on usb flash drive, security tokens, smartphone. but smartphones are easily infected malware, an attacker can steal certificate and private key by malicious code. If an attacker snatchs the certificate, the private key file, and the password for the private key password, he can always act as valid user. In this paper, we proposed a safe way to keep the private key on smartphone using smartphone's unique information and user password. If an attacker knows the user password, the certificate and the private key, he can not know the smart phone's unique information, so it is impossible to use the encrypted private key. Therefore smartphone user use IT service safely.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.1
• /
• pp.1-11
• /
• 2022

PURPOSE. The maximum width between the mesial and distal labial transitional line angles, described as "esthetic width" herein, could significantly influence the visual perception of the teeth and smile. This study aimed to conduct biometric research on esthetic width and to explore whether regular distribution exists in the esthetic width of human teeth. MATERIALS AND METHODS. A total of 4,264 maxillary and mandibular anterior teeth were measured using the Geomagic studio software program. The proportions of maxillary to mandibular homonymous teeth and proportions between the adjacent teeth were calculated. Bilateral symmetry and the correlation between the esthetic and mesiodistal widths were both accounted for during the measurement procedures. RESULTS. The mean esthetic widths were 6.773 ± 0.518 mm and 4.329 ± 0.331 mm for maxillary and mandibular central incisors, respectively, 5.451 ± 0.487 mm and 5.008 ± 0.351 mm for maxillary and mandibular lateral incisors, respectively, and 3.340 ± 0.353 mm and 5.958 ± 0.415 mm for maxillary and mandibular canines, respectively. Except for the mandibular canines, no significant difference in esthetic width was found among homonymous teeth from the same jaw. A high linear correlation was found between the esthetic and mesiodistal widths of the same tooth, except for the maxillary canines. Esthetic width proportions among different tooth categories showed some regular patterns, which were similar to those of the mesiodistal width. CONCLUSION. Esthetic width is regularly distributed among the teeth in the Chinese population. This could provide an important reference for anterior dental restorations and dimension recovery in esthetic reconstruction of anterior teeth.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.5
• /
• pp.1085-1095
• /
• 2015

In music theory, the triton is defined as a musical interval composed of three adjacent whole tones(or six semitones), which generates a harmonic and melodic dissonance. The triton paradox is an auditory illusion which is heard as ascending by some people and as descending by others. In this paper we examine an emerging non-static biometric technique that aims to identify users based on analyzing uniqueness and consistency through the user experiences. We also propose some authentication schemes which provides protection against key logging, shoulder surfing, and brute force attacks.

• Journal of Korea Multimedia Society
• /
• v.16 no.10
• /
• pp.1156-1162
• /
• 2013

Face verification has been widely studied during the past two decades. One of the challenges is the rising concern about the security and privacy of the template database. In this paper, we propose a secure face verification system which generates a unique secure cryptographic key from a face template. The face images are processed to produce face templates or codes to be utilized for the encryption and decryption tasks. The result identity data is encrypted using Advanced Encryption Standard (AES). Distance metric naming hamming distance and Euclidean distance are used for template matching identification process, where template matching is a process used in pattern recognition. The proposed system is tested on the ORL, YALEs, and PKNU face databases, which contain 360, 135, and 54 training images respectively. We employ Principle Component Analysis (PCA) to determine the most discriminating features among face images. The experimental results showed that the proposed distance measure was one the promising best measures with respect to different characteristics of the biometric systems. Using the proposed method we needed to extract fewer images in order to achieve 100% cumulative recognition than using any other tested distance measure.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.12 no.2
• /
• pp.41-49
• /
• 2016

Lossless encryption methods are more applicable than lossy encryption methods when marginal distortion is not tolerable. In this research, the author propose a novel lossless symmetric key encryption/decryption technique. In the proposed algorithm, the image is transformed into the frequency domain using the lifting wavelet transform, then the image sub-bands are encrypted in a such way that guarantees a secure, reliable, and an unbreakable form. The encryption involves scattering the distinguishable frequency data in the image using a reversible weighting factor amongst the rest of the frequencies. The algorithm is designed to shuffle and reverse the sign of each frequency in the transformed image before the image frequencies are transformed back to the pixel domain. The results show a total deviation in pixel values between the original and encrypted image. The decryption algorithm reverses the encryption process and restores the image to its original form. The proposed algorithm is evaluated using standard security and statistical methods; results show that the proposed work is resistant to most known attacks and more secure than other algorithms in the cryptography domain.

• International journal of advanced smart convergence
• /
• v.8 no.1
• /
• pp.44-57
• /
• 2019

Most banks in Korea have provided Internet banking services based on PKI(Public Key Infrastructure) certificates since the early 2000s when Internet banking began in Korea. To support PKI Internet banking, the Korean government backed the electronic signature law and supported the rapid spread of PKI-based Internet banking by regulating the application of PKI certificates to be compulsory in Internet banking until 2015. PKI Internet Banking in Korea has been developed as a pioneer in this field through many challenges and responses until its present success. Korea's PKI banking, which started with soft-token-based closed banking, has responded to various types of cyber attack attempts and promoted the transition to open banking by accepting various criticisms due to lack of compatibility with international standards. In order to improve the convenience and security of PKI Internet banking, various attempts have been made, such as biometric-integrated smartphone-based PKI authentication. In this paper, we primarily aim to share the experience and lessons of PKI banking by analyzing the evolution process of PKI Internet banking in Korea. It also has the purpose of presenting the challenges of Korea's PKI Internet banking and sharing its development vision.