• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.6
• /
• pp.2005-2021
• /
• 2014

This paper proposes a novel image authentication scheme, aiming at tampering detection for block truncation coding (BTC) compressed image. The authentication code is generated by using the random number generator with a seed, and the size of the authentication code is based on the user's requirement, with each BTC-compressed image block being used to carry the authentication code using the data hiding method. In the proposed scheme, to obtain a high-quality embedded image, a reference table is used when the authentication code is embedded. The experimental results demonstrate that the proposed scheme achieves high-quality embedded images and guarantees the capability of tamper detection.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.319-322
• /
• 2002

In this paper, we present a digital authentication technique using content-based watermarking in digital images. To digest the image contents, Hopfield network is employed on the block-based edge image. The Hopfield function extracts the same tit fur similarly looking blocks so that the values are unlikely to change to the innocuous manipulations while being changed far malicious manipulations. By inputting the extracted bit sequence with secret key to the cryptographic hash function, we generate a watermark for each block by seeding a pseudo random number generator with a hash output Therefore, the proposed authentication technique can distinguish between malicious attacks and innocuous attacks. Watermark embedding is based on the block-based spread spectrum method in DCT domain and the strength of watermark is adjusted according to the local statistics of DCT coefficients in a zig-zag scan line in AC subband. The numerical experiments show that the proposed technique is very efficient in the performance of robust authentication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.130-131
• /
• 2018

To day, the number of small game developer has increased, developers who lacked financial resources have difficulty in creating various and quality maps. However, if applied in game that randomly generated maps, development time and human costs will be significantly reduce. In this paper, we describe a method for generating 3D maps with smooth noise maps, can be used in games.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.1
• /
• pp.27-34
• /
• 2017

The signal transmitted from radar is not reflected from a single point when the signal reflected by complex target. Resultantly, the amplitude and phase of the received signal can be changed because the target has lots of scatterers. The changes of the amplitude and the phase mean Glint and RCS, respectively. Although the Glint and RCS that caused by the same scatters are uncorrelated, however, they are not independent completely. Therefore, this paper proposes a method for generating the Glint and RCS by using same random number generator. And the time correlations of the Glint and RCS are respectively implemented in frequency domain by using each power spectral density of them.

• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.209-212
• /
• 2004

실난수 발생기는 소프트웨어로 구현된 의사난수 발생기와는 달리 비결정적인 출력열을 제공하고, 알고리즘의 분해나 노출에 따른 위협이 없으며 의사난수발생기의 시드 값 관리가 불필요하다는 장점 등을 가지고 있다. 그러나 전자회고 잡음을 이용하는 경우 실난수 발생기는 온도나 주변 전자회로 기판 잡음 등으로 인해 지속적으로 편이성을 갖지 않는 안정된 출력 난수열을 얻는 것은 어렵다. 본 논문에서는 실난수 발생기에서 추출된 출력 난수열이 지속적으로 안정화된 출력 수열을 얻기 위한 방안을 연구하였다. 제시한 방안은 출력 난수열 "0"나 "1" 비트의 편이성을 가질 경우 FIPS 140-1에서 제시하고 있는 랜덤성의 조건을 만족하도록 출력 난수열의 랜덤성을 개선하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2019.05a
• /
• pp.219-222
• /
• 2019

IoT 기술이 발달하면서 기기들 간의 안전한 통신을 위한 보안 시스템 탑재의 필요성이 대두되었다. 보안 시스템은 암호 키의 안전성과 밀접한 관련이 있기 때문에, 안전한 난수발생기를 통해 생성한 난수를 키로 사용하는 것이 중요하다. 그러나 제한된 리소스를 갖는 IoT 기기들의 특성으로 인해, 기존 난수발생기를 IoT 기기에 구현하기 어려운 문제가 있다. 이에 IoT 기기에서 사용 가능한 난수발생기에 대한 연구들이 진행되어 왔으며, 특히 IoT 기기들이 탑재하고 있는 각종 센서를 활용한 난수발생기의 설계 방안들이 활발히 연구되고 있다. 본 논문에서는 IoT 기기에 주로 탑재되는 센서를 5가지로 분류하고, 각각의 센서별로 난수성을 측정하는 연구들을 분석한다. 우리가 조사한 바에 따르면 이러한 센서들의 출력이 충분한 난수성을 제공하고 있으며, 본 논문에서 각 센서들을 활용하여 난수발생기를 설계한 연구들을 분류하고 특징을 살펴본다.

• Electronics and Telecommunications Trends
• /
• v.33 no.6
• /
• pp.94-106
• /
• 2018

A quantum key distribution (QKD) provides in principle an unconditional secure communication unlike the standard public key cryptography depending on the computational complexity. In particular, free-space QKD can give a secure solution even without a fiber-based infrastructure. In this paper, we investigate an overview of recent research trends in the free-space QKD system, including satellite and handheld moving platforms. In addition, we show the key components for a free-space QKD system such as the integrated components, single photon detectors, and quantum random number generator. We discuss the technical challenges and progress toward a future free- space QKD system and components.

• Journal of Korea Multimedia Society
• /
• v.24 no.3
• /
• pp.406-415
• /
• 2021

The worldwide spread of the Internet and the digital information revolution have resulted in a rapid increase in the use and transmission of multimedia information due to the rapid development of communication technologies. It is important to protect images in order to prevent problems such as piracy and illegal distribution. To solve this problem, I propose a new digital color image encryption algorithm in this paper. I design a new pseudo-random number generator based on 1D five-neighborhood maximum length cellular automata (FN-MLCA) to change the pixel values of the plain image into unpredictable values. And then I use a 3D chaotic cat map to effectively shuffle the positions of the image pixel. In this paper, I propose a method to construct a new MLCA by modeling 1D FN-MLCA. This result is an extension of 1D 3-neighborhood CA and shows that more 1D MLCAs can be synthesized. The safety of the proposed algorithm is verified through various statistical analyses.

• IEIE Transactions on Smart Processing and Computing
• /
• v.1 no.2
• /
• pp.95-105
• /
• 2012

The widespread implementation of RFID in ubiquitous computing is constrained considerably by privacy and security unreliability of the wireless communication channel. This failure to satisfy the basic, security needs of the technology has a direct impact of the limited computational capability of the tags, which are essential for the implementation of RFID. Because the universal application of RFID means the use of low cost tags, their security is limited to lightweight cryptographic primitives. Therefore, EPCGen2, which is a class of low cost tags, has the enabling properties to support their communication protocols. This means that satisfying the security needs of EPCGen2 could ensure low cost security because EPCGen2 is a class of low cost, passive tags. In that way, a solution to the hindrance of low cost tags lies in the security of EPCGen2. To this effect, many lightweight authentication protocols have been proposed to improve the privacy and security of communication protocols suitable for low cost tags. Although many EPCgen2 compliant protocols have been proposed to ensure the security of low cost tags, the optimum security has not been guaranteed because many protocols are prone to well-known attacks or fall short of acceptable computational load. This paper proposes a remedy protocol to the flyweight RFID authentication protocol proposed by Burmester and Munilla against a desynchronization attack. Based on shared pseudorandom number generator, this protocol provides mutual authentication, anonymity, session unlinkability and forward security in addition to security against a desynchronization attack. The desirable features of this protocol are efficiency and security.

• The KIPS Transactions:PartC
• /
• v.10C no.6
• /
• pp.747-754
• /
• 2003

Thia paper suggests a milti user-authentication system comprises that DNA biometric informatiom, owner's RFID(Radio Frequency Identification) smartcard of hardware token, and PKI digital signqture of software. This system improved items proposed in [1] as follows : this mechanism provides one RFID smartcard instead of two user-authentication smartcard(the biometric registered seal card and the DNA personal ID card), and solbers user information exposure as RFID of low proce when the card is lost. In addition, this can be perfect multi user-autentication system to enable identification even in cases such as identical twins, the DNA collected from the blood of patient who has undergone a medical procedure involving blood replacement and the DNA of the blood donor, mutation in the DNA base of cancer cells and other cells. Therefore, the proposed system is applied to terminal log-on with RFID smart card that stores accurate digital DNA biometric information instead of present biometric user-authentication system with the card is lost, which doesn't expose any personal DNA information. The security of PKI digital signature private key can be improved because secure pseudo random number generator can generate infinite one-time pseudo randon number corresponding to a user ID to keep private key of PKI digital signature securely whenever authenticated users access a system. Un addition, this user-authentication system can be used in credit card, resident card, passport, etc. acceletating the use of biometric RFID smart' card. The security of proposed system is shown by statistical anaysis.